11 Aircraft Systems 747 400 v10

AIRCRAFT SYSTEMS 11 - 1

PMDG 747-400 AOM DO NOT DUPLICATE Revision – 26JUL05

AIRCRAFT SYSTEMS

TABLE OF CONTENTS

SUBJECT PAGEINTENTIONALLY BLANKAIR CONDITIONING / PRESSURIZATION................6

AIR CONDITIONING / PRESSURIZATION..........................................................7Overview .................................................................................................................................7Cabin Temperature..................................................................................................................7Air Conditioning Packs.............................................................................................................7Pack Control ............................................................................................................................8Pack Hi Flow Mode..................................................................................................................8Recirculation Fans...................................................................................................................8Trim Air....................................................................................................................................8Equipment Cooling ..................................................................................................................9Gasper Operation ....................................................................................................................9Humidifie .................................................................................................................................9Secondary EICAS Indications ..................................................................................................9Master Target Temperature: ....................................................................................................9Pressurization Overview ........................................................................................................10Cabin Altitude Control ............................................................................................................10Landing Altitude.....................................................................................................................10Outflow Valves.......................................................................................................................10Cabin Altitude Warning ..........................................................................................................10AIR CONDITIONING/PRESSURIZATION EICAS MESSAGES..............................................11

ELECTRICAL SYSTEM .....................................................................................12Overview ...............................................................................................................................12AC Power ..............................................................................................................................12IDG Drive Disconnects...........................................................................................................12APU / External Power ............................................................................................................13Split System Breaker .............................................................................................................13Power Switching/Preferencing ...............................................................................................14AC Bus Tie System................................................................................................................14Autoland Configuration ..........................................................................................................14Batteries ................................................................................................................................14DC Power ..............................................................................................................................14DC Tie Bus............................................................................................................................15Battery Busses ......................................................................................................................15Main Standby Power..............................................................................................................15APU Standby Power ..............................................................................................................15Transfer Busses.....................................................................................................................15Ground Handling Bus.............................................................................................................16Ground Service Bus...............................................................................................................16Utility and Galley Busses .......................................................................................................16Load Shedding ......................................................................................................................17EICAS ELEC Synoptic ...........................................................................................................17ELECTRICAL CONTROL PANEL DIAGRAMS.......................................................................18

11 - 2 AIRCRAFT SYSTEMS

Revision – 26JUL05 DO NOT DUPLICATE PMDG 747-400 AOM

SECONDARY EICAS DISPLAY - ELECTRICAL SYSTEM SYNOPTIC .................................19Bus Equipment Overview.......................................................................................................20APU Battery Bus Equipment ..................................................................................................20APU Hot Battery Bus Equipment............................................................................................20Main Battery Bus ...................................................................................................................20Main Hot Battery Bus.............................................................................................................20Main Standby Bus..................................................................................................................20APU Standby Bus..................................................................................................................20AC Bus 1 ...............................................................................................................................20AC Bus 2 ...............................................................................................................................21AC Bus 3 ...............................................................................................................................21AC Bus 4 ...............................................................................................................................21DC Bus 1...............................................................................................................................21DC Bus 2...............................................................................................................................21DC Bus 3...............................................................................................................................22DC Bus 4...............................................................................................................................22ELECTRICAL SYSTEM EICAS MESSAGES .........................................................................22

ENGINES AND ENGINE SYSTEMS ..................................................................23Overview ...............................................................................................................................23Electronic Engine Controls.....................................................................................................23EEC NORMAL Mode .............................................................................................................24EEC ALTERNATE Mode........................................................................................................24Engine Indication ...................................................................................................................25Engine Vibrometers ...............................................................................................................25Engine Fuel System...............................................................................................................25Engine Starter/Ignition Systems .............................................................................................25Oil System .............................................................................................................................26Reverse Thrust Capabilities ...................................................................................................26ENGINE START/CONTROL SWITCHES...............................................................................28PRIMARY / SECONDARY EICAS ENGINE DISPLAYS .........................................................29ENGINE THRUST REVERSER ACTIVATION DIAGRAM .....................................................31

FIRE DETECTION / SUPPRESSION SYSTEMS ...............................................32Fire/Overheat Indications.......................................................................................................32Cargo Compartment Fire Detection/Suppression....................................................................32Lower Cargo Fire Switches ....................................................................................................33APU Fire Detection/Suppression............................................................................................33APU Fire/Shutoff Handle........................................................................................................33APU BTL DISCH Light ...........................................................................................................33Using Fire Handles ................................................................................................................33Engine Fire Detection/Suppression ........................................................................................33Engine Fire/Shutoff Handles ..................................................................................................34Lavatory Fire Detection/Suppression......................................................................................34Wheel Well Fire Detection......................................................................................................34FIRE/Overheat Testing ..........................................................................................................34Importance of Procedures......................................................................................................34OVERVIEW OF ENGINE FIRE SUPPRESSION SYSTEM.....................................................35FIRE CONTROL SYSTEM EICAS MESSAGES:....................................................................36



FLIGHT CONTROLS..........................................................................................37Overview: ..............................................................................................................................37Elevators ...............................................................................................................................37Elevator Position Indication....................................................................................................37Horizontal Stabilizer...............................................................................................................37Important Note on Trimming...................................................................................................37Ailerons .................................................................................................................................37Spoilers .................................................................................................................................38Spoiler Position Indication......................................................................................................38Speedbrake Handle Function.................................................................................................38Rudder ..................................................................................................................................39FLIGHT CONTROL CONFIGURATION .................................................................................40Leading and Trailing Edge Flaps............................................................................................41Trailing Edge Flaps................................................................................................................41Leading Edge Slats................................................................................................................41Flap Position Indicators..........................................................................................................42FLIGHT CONTROLS EICAS MESSAGES: ............................................................................43

FUEL SYSTEM...................................................................................................44Overview ...............................................................................................................................44Fuel Pump Systems...............................................................................................................44Fueling ..................................................................................................................................44Fuel Management..................................................................................................................45Main Tank Fuel Pumps ..........................................................................................................45Main Tank 2 and 3 Override/Jettison Pumps..........................................................................45Center Wing Tank Fuel Pumps ..............................................................................................45Crossfeed Manifold and Valves..............................................................................................45Reserve Tank Transfer Valves...............................................................................................46Main Tank 1 and 4 Transfer Valves........................................................................................46Operating With Center Wing Tank Fuel ..................................................................................46Operating With Center Wing Tank Empty...............................................................................47Fuel Quantity Indicating System (FQIS) .................................................................................47Fuel Jettison System..............................................................................................................47Fuel Transfer .........................................................................................................................48Secondary EICAS Fuel System Synoptic ...............................................................................48FUEL SYSTEM AND EICAS FUEL SYSTEM DEPICTION .....................................................49FUEL SYSTEM CONTROL PANEL DIAGRAM ......................................................................49FUEL SYSTEM CONTROL PANEL DIAGRAM ......................................................................50FUEL CONTROL PANEL / FUEL PUMP SCHEMATIC ..........................................................51FUEL SYSTEM EICAS MESSAGES......................................................................................52

HYDRAULIC SYSTEM.......................................................................................53Overview ...............................................................................................................................53Hydraulic Reservoirs..............................................................................................................53Engine Driven Pumps ............................................................................................................53Auxiliary Demand Pumps.......................................................................................................53Electric AUX System..............................................................................................................54Hydraulic System 1................................................................................................................54Hydraulic System 2................................................................................................................54Hydraulic System 3................................................................................................................54Hydraulic System 4................................................................................................................54Hydraulic System 4 AUX........................................................................................................54



EICAS STAT Screen Hydraulic Indicators ..............................................................................54Hydraulic Quantity Warning....................................................................................................54SECONDARY EICAS DISPLAY - HYDRAULIC SYSTEM SYNOPTIC....................................55Secondary EICAS HYD Display .............................................................................................55HYD Display Examples..........................................................................................................55Hydraulic Reservoir Quantity Indicator ...................................................................................55HYDRAULIC SYSTEM CONTROL PANEL ............................................................................56SYS FAULT Light ..................................................................................................................56DEM PUMP PRESS Light......................................................................................................56Demand Pump Selector.........................................................................................................56ENG PUMP Switch ................................................................................................................56ENG PUMP PRESS light .......................................................................................................56HYDRAULIC SYSTEM EICAS MESSAGES...........................................................................57

ICE AND RAIN PROTECTION...........................................................................58Overview ...............................................................................................................................58Probe Heat ............................................................................................................................58Nacelle Anti-Ice .....................................................................................................................58

LANDING GEAR ................................................................................................60Overview ...............................................................................................................................60Landing Gear.........................................................................................................................60Landing Gear Position Indicators ...........................................................................................60Expanded Gear Disagree Indicator ........................................................................................60Landing Gear Brake System ..................................................................................................60Antiskid..................................................................................................................................61Autobrakes ............................................................................................................................61Ground Steering ....................................................................................................................61Landing Gear Configuration Warning .....................................................................................62Secondary EICAS Display - Landing Gear Synoptic ...............................................................62

LIGHTING SYSTEMS.........................................................................................63Overview ...............................................................................................................................63Storm Lights ..........................................................................................................................63Circuit Breaker/Overhead Panel Dimmer................................................................................63Glare shield/Panel Flood Dimmer...........................................................................................63Dome Light ............................................................................................................................63Aisle Stand Panel Flood Dimmer............................................................................................63Landing Lights .......................................................................................................................63Runway Turnoff Lights ...........................................................................................................63Runway Turnoff Lights ...........................................................................................................63Taxi Lights.............................................................................................................................63Beacon Lights........................................................................................................................63Navigation Lights ...................................................................................................................63Strobe Lights .........................................................................................................................64Wing Lights............................................................................................................................64Logo Lights............................................................................................................................64Indicator Lights Test...............................................................................................................64Screen Dimming....................................................................................................................64Emergency Lights..................................................................................................................64



PNEUMATIC SYSTEMS ....................................................................................65Overview ...............................................................................................................................65External Air............................................................................................................................65APU Bleed Air........................................................................................................................65Engine Bleed Air ....................................................................................................................65Engine Bleed Air Valve ..........................................................................................................65Engine Bleed Switch..............................................................................................................65Nacelle Anti-Ice .....................................................................................................................66Distribution ............................................................................................................................66Pneumatic System Indications ...............................................................................................66SECONDARY EICAS DISPLAY - PNEUMATIC SYSTEM SYNOPTIC ...................................67Secondary EICAS Pneumatic Indications...............................................................................67Pneumatic System Control Panel...........................................................................................67Isolation Valve Switch............................................................................................................67SYS FAULT Lights.................................................................................................................67APU Bleed Air Switch ............................................................................................................67Engine Bleed Air Switches .....................................................................................................67

GLOBAL NAVIGATION SYSTEMS ...................................................................68Overview ...............................................................................................................................68Inertial Reference Units..........................................................................................................68

CENTER PEDESTAL SYSTEMS.......................................................................69Overview ...............................................................................................................................69Communications Radios ........................................................................................................69Navigation Radio Signal Monitoring........................................................................................69Autobrakes: ...........................................................................................................................69Flight Control Trimming:.........................................................................................................69Transponder and TCAS Controls: ..........................................................................................69



INTENTIONALLY BLANK



AIR CONDITIONING / PRESSURIZATIONOverview: To provide cabin airconditioning, air from the pneumaticmanifold is directed to three air conditioningpacks. Ozone is removed by catalyticconverters, and after passing through one ofthe three packs, the conditioned air enters acommon air conditioning manifold fordistribution to the cabin.

Conditioned air is then circulated to thecockpit, the upper deck area, and one of fivemain deck cabin condition control zones.Output temperature of the air conditioningpacks is determined by the single zonewhich requires the coolest air output. Theair destined for other zones is warmedabove this temperature level by the additionof hot air from the pneumatic system (trimair.)

ECS Overhead Panel

Cabin Temperature: Cabin temperature iscontrolled by air conditioning in sevenindependent temperature control zones:Five on the main passenger deck, one onthe upper deck and one in the cockpit.Conditioned air is provided by three airconditioning packs located below decks inthe center section of the airplane. Packcontrol, cabin air recirculation, faultprotection and overheat protection are allautomatic. Temperature is controlledautomatically to selected levers for the flightdeck and passenger zones. A backup modeof temperature control is available in theevent of system failures.

The air conditioning packs can operateusing pressurized bleed air from theengines, APU or an external pneumaticground source.

Temperature control is managed byadjusting the temperature of the airconditioned output from the packs to thecoolest zone requirement. Other zones arethen heated using a modulated amount oftrim air to meet commanded temperaturerequirements in those zones. Unlessmanually set, the temperature controlselectors will target an average cabintemperature of 24ºC.

The forward cargo compartment is heatedby the equipment cooling air exhaust fromthe flight compartment and the equipmentcenter. The aft cargo compartment takeshot bleed air directly from the center bleedair duct. Temperature is regulated by atemperature sensing probe and a regulatorvalve. Control of aft cargo heat can beeffected through use of the Aft Cargo Heatswitch on the overhead ECS panel.

The air conditioning system synopticprovides an overview of the aircrafttemperature control zones in the upper leftcorner. This overview includes the mastertemperature setting, target and averagetemperature for each zone, plus the currenttemperature of the forward and aft cargocompartments.

Air Conditioning Packs: Bleed air from thepneumatic manifold passes through twosections of the dual heat exchanger. Thefirst section cools the bleed air then passesit into a compressor for the air cyclemachine. As a result of compression thetemperature of the air increases, so it is thenrouted to the secondary section of the dualheat exchanger, where it is cooled. The



compressed, cooled air then passes throughthe turbine section of the pack where itexpands rapidly causing further cooling. Acondenser/separator eliminates excessmoisture which is produced during theexpansion process.

To prevent ice forming in thecondenser/separator, the temperature of airflowing through the mechanism is controlledby mixing hot air from the compressionstage of the pack.

The air conditioning packs and heatexchangers produce significant amounts ofheat during normal operation. Additionallythey consume bleed air resources from theengines thus increasing EGT values andreducing engine efficiency. It isrecommended that two packs be turned offduring takeoff.

The packs themselves are cooled byinducing air flow over the heat exchangerduring ground operation, and by ram airduring in-flight operation.

Pack Control: Pack control is handled bytwo pack controllers, A and B. Each packcontroller has three control channels, one foreach pack. If either pack controller fails,control will automatically switch to the othercontroller.

Pack controllers can be selectedautomatically, or manually by positioning thepack control selector to NORM, A or B.Provided bleed air is available, this willcause the selected controller to commandpack operation.

In the event of a pack overheat or a fault inthe pack controller, an EICAS advisorymessage is displayed, the pack SYSTEMFAULT light illuminates and the respectivepack valve closes automatically, resulting ina pack shutdown. Pack three will shut downautomatically if any Cargo Fire Extinguishingsystem is armed, and pack two will shutdown automatically if the cabin becomesover-pressurized.

The Pack Controller logic will automaticallychange the pack control mode betweeneach subsequent flight. The pack controlmode can be read from the secondary

EICAS screen for the Environmental ControlSystem (ECS screen.) The pack controlmode is denoted by the letter A or Bassociated with each pack.

If left in NORM, the airplane willautomatically alternate between A and B onsubsequent flights, or the control mode maybe selected manually by the crew in theevent a particular control mode fails.

Pack Hi Flow Mode: Packs normallyoperate in HI FLOW mode at all timesexcept cruise flight. During cruise, thepacks will operate in low flow in order toincrease efficiency and reduce pneumaticdemands on the engines. This may beoverridden by selecting HI FLOW on thepack control switch if desired or necessary.An EICAS memo indicating the HI FLOWsetting will be displayed in order to remindthe crew that the Hi Flow switch is ON andthe pack flow setting is not being managedautomatically.

Recirculation Fans: In order to recirculatepassenger cabin air through the manifoldsystem, four recirculation fans are installed,two overhead and two under floor. Therecirculation fans operate in conjunction withthe air conditioning packs, and arecontrolled by the pack controller. Unlessmanually overridden, the lower recirculationfans will only operate during cruise. Thishelps to reduce engine bleed air demandand fuel consumption. The fans must beactivated using the switches on theoverhead ECS panel.

If a fan overheat is detected, electricalpower is automatically removed from thatfan. If a fan is not operating because of anoverheat, it has failed or the RecirculationFan switch is OFF, system logicreconfigures the pack flow and recirculationfan operating combination to maintainproper ventilation to the cabin.

Trim Air: In order to regulate temperaturedifferences between zones, heated air from



the bleed ducts is used to modulate airtemperature in different zones. This airflowis called Trim Air, and the control for thisfunction is located on the ECS OverheadPanel.

Equipment Cooling: The equipmentcooling system provides cooling air for theflight deck electrical equipment and theelectronics and equipment center racks.This system directs cooler air from the lowerfuselage into the equipment racks andexhausts warmer air to the forward cargocompartment.

The Equipment Cooling system operates inthree modes; NORM, STBY and OVRD.The modes are selected using theequipment cooling selector on the ECSportion of the overhead panel.

On the ground without engine power, theNORM setting will automatically causewarmer exhaust air to be ducted to theforward cargo compartment or out theground exhaust valve if the ambienttemperature is greater than 45º F.

With the selector on STBY, the systemfunctions the same as in NORM mode. Thesystem will not exhaust warmer air out theground exhaust valve, regardless of ambienttemperature, however.

With the selector in OVRD, the equipmentcooling system is deactivated and anoutboard vent is opened, creating airflowacross the equipment, through the supplyduct and overboard through the use of cabindifferential pressure.

Gasper Operation: In order to improveairflow to the passenger service unitslocated above each passenger seat row, agasper system is used to add additionalairflow through the overhead ducting.Operation of this system is controlled by thegasper switch on the overhead ECS panel.

Humidifier: In order to improve humiditylevels which are traditionally very low inpack conditioned air, operation of thehumidification system can be controlledusing the HUMID switch on the overheadECS panel. The humidification system re-introduces moisture to the airflow rather than

routing it through the evaporator.Humidification levels will vary depending onthe number of packs in operation.

Secondary EICAS Indications: A synopticof the air conditioning system is provided onthe Environmental Control Systems (ECS)page, which is selected using the ECSswitch on the secondary EICAS controlpanel.

Main Deck Temperature by Zone:

Flight Deck/Upper Deck Temp:

Master Target Temperature:

FWD and AFT Cargo Zone Temp:

Pack Controller and Hi Flow Indication:



Pressurization Overview: The cabin ispressurized with conditioned air from the airconditioning packs. Cabin altitude iscontrolled by regulating the discharge ofconditioned air through two outflow valves atthe rear of the cabin. The system isnormally fully automatic but the outflowvalves may be positioned manually ifrequired due to a system failure or as aresult of some contingency with the normalsystem or requirement in the event of anonboard smoke source. There are twocabin altitude controllers designated A andB. Although both controllers simultaneouslyreceive identical information, only onecontroller is active at a time.

Pressurization Control Panel

Cabin Altitude Control: The active cabinaltitude controller uses origin airportelevation, cruise altitude and landing altitudeinformation from the FMS and automaticallypositions the outflow valves to conform tocabin altitude climb and descent rate limits,differential pressure limits and to achieve thecorrect landing cabin altitude. The initialpressurization, slightly above ambientpressure, begins when the airplane reaches65 knots ground speed. The cabin altitudecontroller automatically sets cabin altitudeslightly below destination field elevation sothe cabin is pressurized slightly on landing.At touchdown, the outflow valves open,depressurizing the cabin.

Landing Altitude: Landing altitude may beentered manually into the cabin altitudecontroller using the Landing Altitude knob.This switch allows selection of numericalsettings from 1,000feet below sea level to14,000 feet MSL. Normally the landingaltitude is set automatically by informationreferenced to the FMS. An EICAS advisorymessage LANDING ALT is displayed if thelanding altitude information is not available

from the FMC The message is inhibited ifboth cabin altitude controllers A and B fail.

Outflow Valves: The outflow valves arelocated on the bottom of the aircraft aft ofthe lower aft cargo compartment. They arebifold type valves that operate independentlyof each other. Each outflow valve has an ACmotor and a DC motor. The AC motor isused to position the outflow valve whenoperating in the automatic mode ofoperation. An EICAS advisory messageOUTFLOW VLV L (R) is displayed ifautomatic control is inoperative or themanual mode is selected for the respectivevalve. An EICAS caution message CABINALT AUTO is displayed if both cabin altitudecontrollers are inoperative or both outflowvalves are in the manual mode.

If either Outflow Valve Manual switch is ON,the Outflow Valves Manual control may beused to open or close the respective outflowvalve using the slower operating DC motor.The outflow valve not selected for manualoperation remains under the control of thecabin altitude controller. When an OutflowValve Manual switch is ON, the cabinaltitude controller and the cabin altitudelimiter are bypassed for the respectiveoutflow valve. If both Outflow Valve Manualswitches are ON, all automatic cabin altitudecontrol functions are bypassed. Outflowvalve position indicators are located on thecabin altitude panel and the ECS synoptic.

Cabin Altitude Warning: The EICASwarning message CABIN ALTITUDE isdisplayed and a siren sounds if cabinaltitude exceeds 10,000 feet. The messageis no longer displayed and the siren silenceswhen cabin altitude descends below 9,500feet. The siren may also be silenced bypushing the Master Warning/Caution Resetswitch. With the system operating in theautomatic mode, the outflow valvesautomatically close when cabin altitudeexceeds 11,000 feet.



AIR CONDITIONING/PRESSURIZATION EICAS MESSAGES:

CABIN ALTITUDE Cabin altitude exceeds 10,000 feet.

CABIN ALT AUTO Failure of both cabin altitude controllers or both outflow valveMANUAL switches ON.

EQUIP COOLING With Equipment Cooling selector in NORM or STBY, airflow isinadequate, or overheat or smoke detected. With selector inOVRD, differential pressure for reverse flow cooling isinadequate, or ground exhaust valve not in commanded position.

>E/E CLNG CARD Message inhibited in flight.On Ground: Control card failure.

LANDING ALT Disagreement between FMC landing altitude and cabin pressurecontroller landing altitude.

OUTFLOW VLV L(R) Auto control of L or R outflow Valve inoperative, or MANUAL wasselected for the respective valve.

PACK 1, 2, 3 Pack Controller FaultPack Operation FaultPack overheat or Pack 2 shutdown with either cabin pressurerelief valve open.

PACK CONTROL Automatic control of outlet temperature of all packs has failed.

PRESS RELIEF Either pressure relief valve actuates and pack 2 fails to shutdown.

TEMP CARGO HEAT Cargo compartment overheat and the temperature control valvefailed to close. (Inhibited on ground)

TEMP ZONE Zone duct overheat sensed or master trim air valve failed closedor zone temp controller failed.Cabin temperature control is in backup mode.

>TRIM AIR OFF Master trim air valve commanded closed.

PACK 1,2,3 OFF Pack 1, 2, 3 off. Inhibited by PACK 1,2,3 advisory message.

PACKS HI FLOW Packs hi flow manually selected by HI FLOW switch.

PACKS OFF All 3 packs selected off.

PACKS 1+2 OFF Packs 1 and 2 selected off.

PACKS 2+3 OFF Packs 2 and 3 are selected off.

PACKS 1+3 OFF Packs 1+3 are selected off.



ELECTRICAL SYSTEMOverview: The electrical system on the747-400 is highly automated, and wasdesigned from the beginning to both reducepilot workload and provide a higher level ofdependability. The electrical systemprovides for automatic system faultdetection, automatic system fault isolationand reconfiguration, load management, on-line power, no-break power switching, ACand DC system status monitoring andmaster frequency referencing. The electricalsystem is also designed to automaticallyconfigure itself to provide the tripleredundant power required by the autopilotsystem for full autoland capability.

Electrical Control Panel

AC Power: Each engine contains anIntegrated Drive Generator (IDG) which isattached to a constant speed drive locatedin the accessory section of it’s respectiveengine. The constant speed drive providesa constant, normal rotation for the generatoracross a broad range of engine RPM.

Each IDG provides 115 volt, 400 hertz ACpower to its individual bus, and is capable ofproviding 90 KVA. Each IDG incorporates agenerator, a constant speed drive and an oilcooling system. The oil cooling system is astandard configuration Fuel/Oil heatexchanger which serves the dual purpose ofheating the fuel system and cooling the IDG.

IDG Drive Disconnects: The constantspeed drive that operates the IDG in eachengine can be separated from the accessorysection in the event of a fault or failure. TheIDG Drive Disconnect switches located onthe Electrical Panel on the overhead provideaccess to this disconnect function.Disconnecting an IDG drive should only beconducted at the request of maintenance, orin the conduct of an Abnormal Checklist, asthe disconnect action will cause the loss ofthat generator for the remainder of the flight.

When starting or shutting down an engine, itis not uncommon to see the DRIVEannunciation in the IDG Disconnect switch.This annunciation indicates that the constantspeed drive lacks sufficient oil pressure orrotational energy to provide adequate powerfrom an IDG.

NOTE: Once an IDG is disconnected, itcannot be reactivated in flight.Disconnected IDGs must be inspected andreset by ground maintenance personnel.

We have provided an IDG reconnect optionin the PMDG/OPTIONS/VARIOUS menu inorder to allow for the practice of failurescenarios that might call for an IDGdisconnect in flight.



APU / External Power: While on theground, it is possible to provide AC power tothe 747-400 via an external power source orthe Auxiliary Power Unit generator. Theelectrical system is designed so that bothmethods of providing electrical power can beused simultaneously on different portions ofthe electrical system.

Two non-paralleled 90KVA generators aredriven by the APU and are capable ofproviding 115 Volt, 400 hertz AC power toeach AC system while the aircraft is on theground.

To simulate differences in various airportfacilities around the world, PMDG hasincluded a logic parameter that will provideExternal Ground Power for EXT1 whenselected from thePMDG/OPTIONS/VARIOUS menu. (SeeChapter 00 Introduction for moreinformation.) Occasionally, the groundpower will also be made available on EXT2.

Split System Breaker: The electricalsystem on the 747-400 is divided into twosystems, Left and Right. The left system iscomprised of Bus 1 and 2, while the rightsystem is comprised of Bus 3 and 4. Thetwo sides are separated by a Split SystemBreaker (SSB). The SSB condition willalternate between open and closed basedon a complex logic designed to ensureredundancy and protection of the entireelectrical system.

If the left and right sides of the airplane arepowered by non IDG sources (EXT1 andAPU2, for example) then the SSB will open,allowing each to power its own side of theairplane.

To understand the behavior of the SSB, it isimportant to understand that the only powersources that can be paralleled on the 747-400 are IDGs. All other power sources mustoperate independently on their side of theairplane.

For example if External Power is active onboth sides of the airplane, the SSB will beopen. If APU power is active on both sidesof the airplane, the SSB will be open. If

IDGs are powering both sides of theairplane, the SSB will be closed.

It is possible to power the left and right sidesof the airplane using dissimilar powersources. If the right side of the airplane ispowered by an APU generator, while the leftside is powered by Ground Power, then theSSB will open to allow both sides to receivepower from the selected source whilepreventing them from being paralleled.

When first beginning to power the aircraft,the behavior of the SSB will depend uponwhat power sources are AVAILABLE.(AVAILABLE means that the source isavailable for use, but has not been selectedas an ACTIVE power source.) If only EXT1is showing as AVAIL on the electrical panel,then the SSB will remain open when EXT1is selected.

The only way to close the SSB, thusproviding power to the entire airplane, is fora power source to be AVAILABLE for theright side of the airplane, whether it is in useor not.

For example, if only EXT1 is available, it willpower the left side of the airplane whenselected ON. The right side will remainunpowered unless:

EXT2 becomes AVAILABLE.APU2 becomes AVAILABLE.

It is not necessary to select either EXT2 orAPU2 on, it is only necessary that they beavailable in order to provide power to triggerthe SSB to close.

If the second source (either APU or EXTPWR) is selected for the other side of theaircraft, the SSB will open and both systemswill run from their selected power sources.

In the event that two power sources are inuse powering each the left and the rightsystem, the SSB provides a safety backup inthe event one source should fail. If one of



the two power sources fails, the SSB willclose automatically, and power will continueto be provided to both the Left and Rightsystems without interruption.

Power Switching/Preferencing: Whenboth systems are being powered by enginedriven IDGs, selection of either an APU orEXT power source will automatically takeboth IDGs on that side of the electricalsystem offline, and will instead providepower from the newly selected source.

If APU or EXT power is selected on theother side of the electrical system, then theentire electrical system will be powered fromnon IDG sources. (And the SSB will remainopen!)

If the entire system is being powered by nonIDG sources, the SSB is open. If an IDG isthen brought online on the right side of thesystem, the IDG will take over powerproduction from the previously selectedpower source, but the IDG will remain OPENbecause the left side of the airplane is beingpowered by a non IDG source.

If an IDG is then selected for the left side ofthe electrical system, the SSB will close, andboth sides will be powered by IDG sources.

When power is transferred from IDGs to anAPU or EXT source, the systemautomatically synchronizes the electricalcurrent to ensure a no-break powercondition is maintained.

AC Bus Tie System: There are four ACbuses on the 747-400, each is directlypowered by its respective IDG, or alternatelyby the system bus in the event therespective IDG has failed or is offline.

Each of the AC buses is connected to the tiebus by a Bus Tie Breaker (BTB). Placingthe BUS TIE switch in AUTO will commandthe BTB to open and close automatically inorder to maintain the integrity of the systemin the event of a system fault. If the BUSTIE switch is placed in ISLN, the BTB andthe DC ISLN relay will open, separating thatAC bus from the rest of the system.

If the power on an AC bus becomesunsynchronized, the BTB will openautomatically and the isolated bus willcontinue to operate from it’s own IDG.

Conversely, if the IDG is not able to maintainacceptable power quality for the AC bus,then the respective generator controlbreaker will open and the bus tie will close topower the bus form the synchronous bus.

Autoland Configuration: During autolandmaneuvers, AC buses 1-3 are automaticallyisolated in order to provide redundant powerto each of the FCCs.

Batteries: The 747-400 has two nickel-cadmium batteries. One battery is the mainbattery and the other powers the APUstarter. Each battery has a battery chargerwhich is powered by the external powersource. The batteries, if fully charged, canprovide power to all standby loads for aminimum of 30 minutes.

DC Power: Four 75 amp Transformer-Rectifiers (TR’s) are powered, one by eachAC bus. The TR’s provide power to DC



buses 1-4, respectively. The DC buses canbe paralleled or isolated.

DC Tie Bus: With the BUS TIE switch inAUTO, each DC isolation relay operatesautomatically, and will remain closed if noDC faults are detected. With the BUS TIEswitch set to ISLN, the respective system isopened, which isolates the DC bus from thetie bus and leaves it powered only by therespective AC bus and TR.

Battery Busses: There are four batterybusses:

Main Battery Bus Main Hot Battery Bus APU Battery Bus APU Hot Battery Bus

The hot busses are always connected totheir respective batteries and are normallypowered by the ground service bus throughthe battery chargers if the ground servicebus is powered.

The main and APU battery busses arenormally powered by DC bus 3.

On a cold aircraft with AC bus 3 and /or DCbus 3 unpowered, when the battery switch ispushed ON, the main hot battery bus andthe APU hot battery bus automatically powertheir respective main battery busses.

Main Standby Power: Power to the Mainand APU Standby busses is primarilycontrolled by the STANDBY POWERselector in conjunction with the BatterySwitch.

Under normal conditions, the Main StandbyBus receives its power from AC bus 3.

In the event that AC bus 3 is unpowered andthe STANDBY POWER selector is in the

AUTO position, the Main Standby bus will bepowered from the main standby inverter.The standby inverter will draw it’s powerfrom AC bus 1 (via the ground service bus,the main battery charger and the main hotbattery bus). The BATTERY switch must beon for this backup to function properly.

If both AC bus 1 and AC bus 3 areunpowered, the standby bus is poweredfrom the main battery through the main hotbattery bus and the standby inverter.Battery power can be expected to power themain standby bus for at least 30 minutes.The battery switch must be ON and thestandby power selector must be in theAUTO position for this transfer to take place.

If the STANDBY POWER selector is rotatedto the BAT position and the battery switch isON, the standby bus is powered by the mainbattery via the main hot batter bus and thestandby inverter. The APU battery bus ispowered by the APU battery through theAPU hot battery bus. (In this configurationthe APU battery chargers are disabled.)The standby bus can be powered in thisconfiguration for at least 30 minutes. (Thisconfiguration is not used in any flightoperation and is used primarily bymaintenance.)

APU Standby Power: With the STANDBYPOWER selector in AUTO, flight criticalitems can also be powered by the APUstandby power bus automatically in theevent of a critical loss of AC power.

The APU standby bus will automaticallyprovide power to the primary EICAS,captains PFD, ND and CDU, the VORreceivers and the ILS receivers.

Transfer Busses: Many of the captain’sand first officer’s flight instruments receiveAC power from their respective transferbusses. The captain’s transfer bus isnormally powered by AC bus 3 and the firstofficer’s transfer bus is normally powered byAC bus 2. AC bus 1 provides automaticbackup for both transfer busses. There areno flight deck controls or indicators for thetransfer busses.

Captains Transfer Bus Equipment:• Avionics and Warnings



• System Status Assembly• Center Air Data Computer• Center Engine Instrumentation Unit• Left FMC• Left High Frequency Radio• Left Navigation Display• Left Primary Flight Display• APU Standby Bus

First Officer s Transfer Bus Equipment• Secondary EICAS• Autothrottle Servo• Right Air Data Computer• Right EFIS Control Panel• Right Engine Instrumentation Unit• Right FMC• Right High Frequency Radio• Right Navigation Display• Right Navigation Display• Right Primary Flight Display•

Ground Handling Bus: The GroundHandling Bus is powered by either APU1generator or EXT1 power source.

The bus is powered automatically wheneverexternal power or APU power isAVAILABLE, whether or not that powersource is selected ON. If both APU andEXT power are available, priority goes toexternal power. The ground handling buscan only be powered with the aircraft is onthe ground. If any three engines areoperating above 75% N2 the groundhandling bus will inhibit. There are no flightdeck indicators for the Ground HandlingBus.

Ground Handling Bus Equipment:• Fueling System• Cargo Systems• Cargo Deck Lighting• Auxiliary Hydraulic Pump 4

Ground Service Bus: The Ground ServiceBus is normally powered automatically byAC bus 1. Although not modeled in thisversion, if AC bus 1 is not powered while theaircraft is on the ground, there is a button atthe door 2L flight attendant control panelthat allows the Ground Service Bus to beconnected to the ground handling bus inorder to provide power to the cabin forcleaning, preparation while the aircraft has

AVAILABLE power, but is not activelyconnected.

Ground Service Bus Equipment:• Main and APU battery chargers• Fuel pump for APU start.• Horizontal stabilizer pump for

defueling.• Upper deck doors• Flight deck floodlights• Navigation lights• Cabin and service lighting• Cabin service power outlets

Utility and Galley Busses: Each main ACbus provides power to a utility bus and agalley bus. Each utility and galley bus iscontrolled by a separate electrical loadcontrol unit (ELCU) which protects theelectrical system from utility and galley busfaults and provides load shedding functions.The ELCUs are controlled by the left andright utility power switches located on theoverhead electrical panel.

With the left utility power switch ON, theutility and galley busses 1 and 2 areactivated and the busses are poweredaccording to ELCU logic. Similarly, the rightutility power switch activates utility andgalley busses 3 and 4.

A guarded Emergency Power Off switch islocated in each galley. If this switch ismoved to the OFF position, an EICASadvisory message ELEC UTIL BUS L, R isdisplayed and the OFF light in the respectiveutility power switch illuminates. In this event,cycling the utility power switch to OFF thenON will not reset the indications because theswitch in the galley is forcing the powerdisconnect.



The utility power switch should remain in theON position after cycling, however as thispermits the remaining utility and galleybusses to be powered.

Load Shedding: In the event that ACpower availability decreases due to engineor generator failure, the ELCUs reduce ACpower load requirements by shutting downthe galley buses until AC power availabilityincreases, or until the AC load has beenreduced to a level sustainable with thecurrent supply.

During load shedding, associated EICASalert messages and illumination of the utilityswitch OFF lights are inhibited. However,the following EICAS advisory messagesmay be displayed in the order showndepending upon fuel system configurationand the extent of load shedding:

• FUEL PUMP 3 FWD• FUEL OVRD 2 FWD• FUEL OVRD 3 FWD• FUEL OVRD CTR L• FUEL PUMP 2 FWD

If available power increases, ELCU logic willreturn power to shed busses to the degreesustainable power is available.

EICAS ELEC Synoptic: The EICAS ELECsynoptic displays the current status of theentire bus tie system. The SSB, each of theIDGs, GEN CONT, BUS TIEs and ISLNswitches are displayed in graphic format toquickly allow the crew to asses thedisposition of the electrical system.Electrical flow is depicted by heavy greenbars. During autoland, the EICAS ELECdisplay will be inhibited once the FlightControl Computers engage for autoland.



ELECTRICAL CONTROL PANEL DIAGRAMS(Overhead)

Standby Power Selector:OFF: Disconnects the main and APUstandby buses from all power sources.Standby power is not available.

AUTO: Allows main and APU standby busesto be powered automatically from AC bus 3or batteries.

BAT: Powers the main and APU standbybuses from their respective batteriesprovided the BATTERY switch is ON.

Battery Switch:ON: Enables main and APU batteries andenables backup power.

OFF: Disconnects main and APU batteries.

APU GEN ON Lights: Indicates APUpower breaker is closed.

APU GEN AVAIL Lights: Indicates thatoutput voltage and frequency of the APUgenerator are within normal limits and ready.

APU GEN Switches: Allows selection/de-selection of power APU generator power tobus.

EXT PWR Switch: Allows selection/de-selection of external power to bus.

EXT PWR AVAIL Lights: Indicates thatexternal power unit is connected and voltageand frequency are within normal limits.

EXT PWR ON Lights: Indicates externalpower contactor is closed.

BUS TIE Switches:AUTO: Allows bus tie breaker and DCisolation relay to close automatically ifrequired.

OFF: bus tie breaker and DC isolation relayopen.

UTILITY Power Switches:ON: Each switch powers two galley and twoutility buses unless load reduction isnecessary.

OFF: Respective galley and utility buses aredisconnected from AC power. (Resetscircuitry on buses.)



BUS TIE ISLN Lights: Respective AC busis isolated from the tie bus as the bus tiebreaker is opened due to a fault or theswitch has been selected OFF.

GEN CONT Switches:ON: Closes the generator field and allowsthe generator control breaker to closeautomatically when required.

OFF: Opens generator field and controlbreaker.

GEN OFF Lights: Generator controlbreaker is open.

DRIVE DISC Switches: Disconnects IDGfrom the engine. Can only be reconnectedon the ground.

DRIVE Lights: Generator drive has low oilpressure or high oil temperature.

SECONDARY EICAS DISPLAY - ELECTRICAL SYSTEM SYNOPTIC

DRIVE TEMP/PRESS: Indicates high driveoil temperature or low drive oil pressure.

Split System Breaker (SSB):[Closed] Connects both tie bus halves.[Open] splits tie bus into two halves.

ISLN: Indicates respective BTB is open.

Utility/Galley: [amber] Utility busunpowered. [green] Utility bus powered.

BUS: [amber] Bus unpowered.[green] Bus powered.

GEN CONT: [ON] Generator field closed.[OFF] Generator field open. (Resets)



Bus Equipment Overview: Following is anon-conclusive list describing the equipmentpowered by the primary busses in the ACand DC systems on the 747-400.

APU Battery Bus Equipment:APU battery overheat protectionAPU DC fuel pumpAPU fire/bleed duct overheat loops A and BCabin interphoneCaptain’s interphoneElectronic Engine Control 1-4 channel AEngine 1-4 fire/overht detect loops A and BEngine 1-4 speed sensors 1 and 2Engine start air control First officer’sinterphone Left VHFLeft radio communication panelNacelle anti-ice valve actuate 1-4Observer's interphonePassenger address systems 1-4Primary landing gear display and controlService interphone

APU Hot Battery Bus Equipment:APU duct overheat APU fire warning hornAPU inlet doorAPU primary controlIRU left, center, and right DCLeft and right outflow valves

Main Battery Bus:APU alternate controlE/E cooling smoke overrideEngine 1-4 fuel control valvesEngine 1-4 fuel crossfeed valvesFlight deck dome lightsFlight deck storm lightsFlight deck, captain’s indicator lightsGenerator drive disconnect 1-4Hydraulics EDP supply 1-4Left ILS antenna switchLeft and right manual cabin pressurizationLeft aural warningLeft stabilizer trim/rudder ratio moduleLeft stick shakerOxygen resetOxygen valve and indicationParking brakePrimary trailing edge flap control DCStabilizer trim alternate control Standbyaltimeter vibratorStandby attitude indicatorStandby attitude indicator ILS deviation barsUpper yaw damper

Main Hot Battery Bus:ACARS DCAPU fire extinguisherAPU fuel shutoff valveEngine 1-4 fire extinguishers A and BEngine 1-4 fuel shutoff valveFire switch unlockGalley/Utility ELCU control bus 1-4Generator Control Units 1-4Hydraulic system 2 and 3ELCU controlIRS on battery warningLower cargo fire extinguisherMain battery overheat protection

Main Standby Bus:Avionics and warning systemFlight control 1L and 2L ACLeft ADCLeft EFIS controlLeft EIULeft FMS-CDULeft ILSLeft VORPrimary trailing edge flap control ACRMIStandby ignition 1-4Standby instrument lightsUpper EICAS

APU Standby Bus:Left FMCLeft PFDLeft ND

AC Bus 1:Center FCCCenter FMS-CDUCenter ILSCenter IRUCenter radio altimeterEngine 1 probe heatEngines 1-4 igniter 1Flight control 1R ACL and R wing gear alt extensionLE flap drive group A controlLeft AOA heatLeft aux pitot probe heatLeft pitot probe heatLeft TAT probe heatTR unit 1Voice recorder



AC Bus 2:ACARS ACBody gear steering controlFlight control 2R ACLeft and right wing anti-ice valvesLower rudder ratio changerRight ADFRight ATC transponderRight DME Right FCCRight ILS Right IRURight radio altimeterRight VORRight weather radar R/TTR unit 2Wheel well fire detectionWindow heat 1R, 2L, 3R

AC Bus 3:Engines 1-4 igniter 2Engines 2 and 3 probe heatFirst officer’s panel lightsGlare shield flood lightsGPWSLE flap drive group B controlLeft ADFLeft ATC transponderLeft DME Left FCCLeft IRULeft radio altimeterLeft weather radar R/TObserver’s panel lightsOverhead panel lights 2Pilot’s main panel flood lightsTCASTR unit 3Upper rudder ratio changerWindow heat 2R and 3L

AC Bus 4:Captain’s panel lightsEngine 4 probe heatEngines 1-4 vibration monitorGlare shield panel lightsLeft and right body gear alt extensionNose gear alt extensionOverhead and P7 panel lightsOverhead panel lights 1Right AOA heatRight aux pitot probe heatRight pitot probe heatRight TAT probe heatTR unit 4Window heat 1LWindshield washer pump

DC Bus 1:Auto cabin press controller AFirst officer’s digital display lightsFirst officer’s indicator lightsFlight control 1R DCFlight deck door releaseFuel system management card AFuel transfer valve main 1Fuel transfer valve reserve 2A and 3AGround safety relayHYDIM system 4Hydraulic demand pump 1 controlHydraulic sys 1 EDP depress controlIgnition controlLeft center and main 3 jettison valvesLeft FMCS autothrottle servo

DC Bus 2:Auto cabin press controller BFlight control 2R DCFuel system management card BFuel transfer valve main 4Fuel transfer valve reserve 2B and 3BHYDIM system 3Hydraulic demand pump 2 controlHydraulic sys 2 EDP depress controlLanding gear alt display and controlLower yaw damperNose gear steering - primaryOutboard aileron lockoutRight center and main 2 jettison valvesRight FMCS autothrottle servoRight MCP Right refuelRight stabilizer trim controlRight stabilizer trim rateRight stabilizer trim shutoffRight stick shakerWing anti-ice control



DC Bus 3:Aileron trim controlCenter VHFFuel jettison controller A Fuel quantity 1HYDIM system 2Hydraulic demand pump 3 controlHydraulic quantity indicatorHydraulic sys 3 EDP depress controlInboard TE flap controlLeft Jettison nozzle valve controlLeft MCPLeft stabilizer trim controlLeft stabilizer trim rateLeft stabilizer trim shutoffLeft windshield wiperMaster trim air controlNose gear steering – alternateOverhead and P7 panel lightsPack temperature controller A

Rudder and stabilizer indicatorsRudder trim controlSpeed brake auto controlWindshield rain repellent

DC Bus 4:Fuel jettison controller BFuel quantity 2Hyd sys 4 EDP depress controlHYDIM system 1Hydraulic demand pump 4 controlOutboard TE flap electric controlPack temperature controller BRight Jettison nozzle valve controlRight windshield wiperSpeed brake flight detentSpoiler and aileron position indicationWindshield washer

ELECTRICAL SYSTEM EICAS MESSAGES:>BAT DISCH MAIN Respective battery is discharging.>BAT DISCH APU Respective battery is discharging.

>BATTERY OFF Battery Switch is off.

>DRIVE DISC 1,2,3,4 Generator drive disconnect switch pushed, IDG manuallydisconnected.

ELEC AC BUS 1,2,3,4 AC Bus is unpowered. Additional related messages displayedfor unpowered equipment.

ELEC BUS ISLN 1,2,3,4 Bus tie breaker is open. (Inhibited when ELEC AC BUS isdisplayed)

ELEC DRIVE 1,2,3,4 Low IDG oil pressure, or high IDG oil temperature. Inhibitedwhen IDG disconnected manually.

ELEC GEN OFF 1,2,3,4 Generator control breaker is open with respective enginerunning. Inhibited when ELEC AC BUS message is displayed.

>ELEC SSB OPEN Split system breaker is open when commanded closed.

ELEC UTIL BUS L, R, OFF Galley or Utility bus has tripped off, or Utility power switch L or Ris positioned off, or Galley Emergency Power Off switch wasactivated. Inhibited during load shedding.

>STBY POWER OFF Standby bus is unpowered.

>STBY BUS AP APU Standby bus is not powered.

>STBY BUS MAIN Main standby bus is not powered.



ENGINES AND ENGINE SYSTEMS

Overview: The 747-400 has three enginevariants certified for the airframe.

• General Electric CF6-80C2BF1F@62,100lbs thrust.

• Rolls Royce RB211- 524H2T@59,500lbs thrust.

• Pratt & Whitney PW4062 @ 63,300lbs thrust.

Note that there are an array of enginevariants by each manufacturer currentlyflying on the wings of 747-400s. As variousengine offerings have been improved uponto match the needs of 747-400 operators,engine model variant availability haschanged over time. Operationally thedifferences between model variants isgenerally quite small.

The PMDG 747-400 engine mathematicalperformance model is based upon the GECF6-80C2BF1F engine model at 58,000lbsof thrust. Extensive engine performancedata was used to produce an engine thrustand operative model that most closelyresembles its real world counterpart.

We recognize that users may wish to fly a747-400 that uses engines other than theCF6, (BA for example uses only the RRengine on their airplanes) and as such wehave provided all three engine modelsattached to the visual model of the airplane.

It is important understand that while we haveincluded visual models of each engine type,we have only designed a singlemathematical model for engineperformance. This mathematical model isbased upon the GE CF6 engine.

The Rolls Royce and Pratt & Whitneyengines are instrumented significantlydifferently than the GE engine offering. (TheRR engine is a three spool engine, forexample, and the PW engine uses EPRrather than N1% for thrust control) As such,producing three engine performancemathematical models would also haverequired changes to engine displays, engine

behavior calculations, autothrottle controllaws and numerous small, but significantcockpit items.

We may at a future date offer additionalengine performance mathematical models.For most operators, the engine differencesbetween airplanes represent almostinsignificant performance differences for theairplane.

The GE CF6 engines are two rotor turbofanengines with the N1 and N2 stagesindependent of each other. The N1 rotorconsists of a fan, a low pressure compressorsection and a low pressure turbine section.The N2 rotor consists of a high pressurecompressor section and a high pressureturbine section. The N2 section drives theaccessory pack for each engine, and thebleed air powered starter connects to the N2rotor.

Each engine is fully monitored andcontrolled by an independent ElectronicEngine Control (EEC) which monitorsthrottle input and manages engine controlautomatically to provide peak efficiency in allregimes of flight. The EEC draws powerfrom a dedicated alternator located withinthe engine accessory pack, and is notdependent on the aircraft electrical system.

EEC data on engine performance for eachengine is displayed via the EICAS system inthe cockpit.

Throttle control is provided for the full rangeof forward and reverse thrust. Fuel controlis provided via FUEL CONTROL switches,engine start is controlled by engine STARTswitches and ignition control via IGNITIONswitches.

Electronic Engine Controls: The EEC is asystem of sensors, actuators andvibrometers located within the enginenacelle, the engine casing and within theengine itself. The EEC reads and interpretsraw data from each sensor as well as control



input from cockpit controls and switches.The EEC maintains full control authority overthe engine at all times, and providesprotection from exceeding engine limitationssuch as temperature and rotational speed.

EEC NORMAL Mode: In the normal mode,the EEC sets thrust by controlling N1%based on the throttle position. The EECincreases thrust from idle to maximum asthe throttle is moved through its entire rangeof motion. Thrust will reach maximum N1 atthe full forward throttle position. MaximumN1 is the maximum thrust available from theengine, regardless of flight enveloperestrictions. Maximum thrust is availableduring any phase of flight, regardless ofother restrictions.

When accelerating the engine, EEC willmonitor parameters within the engine toensure that no limitations are exceeded.Fuel flow to the engine is strictly controlledin order to prevent over temperatureconditions during rapid increases in thrust.

Once engine thrust is stabilized, the EECwill continually adjust engine fuel meteringand other parameters based onenvironmental conditions in order tomaintain the thrust setting demanded by thethrottles. This eliminates the need for re-trimming the throttles during the climb, orconstant engine performance monitoring.As such, a fixed throttle position will deliverthe same engine performance throughout aclimb or descent.

The EEC will automatically adjust engineperformance to compensate for bleed airsystem loads such as those imposed bywing and engine nacelle anti-ice, cabinpressurization or in flight engine starts.

When idle thrust is selected, the EEC willchoose between approach idle or minimumidle thrust setting. Minimum idle is a loweridle setting used during ground and taxioperations. Approach idle is a higher idlepower setting used if the flaps and landinggear are out of the UP position. This higheridle power setting will reduce the timeneeded for the engines to spool from idle toa go around power setting.

The EEC also provides engine overspeedprotection. If either the N1 or N2 rotorsapproach the engine overspeed envelope,the EEC will adjust fuel metering to preventrotor speed from exceeding the operatinglimit.

EEC ALTERNATE Mode: In the alternatemode, the EEC sets thrust by controlling N1RPM based on throttle position. Thealternate mode does not provide thrustlimiting at maximum N1% if Maximum N1 isreached at a throttle position less than fullforward. The throttles must be adjusted tomaintain desired thrust as environmentalconditions and bleed requirements change.

If the EEC detects a fault and can no longercontrol the engine using the normal mode, ittransfers control automatically to thealternate mode. The alternate control modecan also be selected manually using theELEC ENG CONTROL switch on theoverhead panel for each enginerespectively.

EEC Control Panel

The alternate mode provides equal orgreater thrust than the normal mode for thesame throttle position. Thrust does notchange when the EEC transfers controlautomatically from the normal to alternatemode. Thrust increases when control isselected manually. When thrust is greaterthan idle, the throttle should be moved afterprior to manually selecting the alternatemode so thrust does not exceed maximumN1%.

The EEC’s have redundant systems. A lossof redundancy may degrade EEC operation.If three or more EECs are operating in thisdegraded condition, the EICAS advisorymessage ENG CONTROLS is displayed.The EICAS advisory message ENGCONTROL is displayed if one EEC systembecomes unreliable. The ENGE CONTROL



and ENG CONTROLS messages aredisplayed only on the ground.

If control for any EEC transfers from thenormal to the alternate mode, theautothrottle disconnects automatically. Theautothrottle can be re-engaged after allEECs are again in the normal mode.

Engine Indication: Engine parameters asmeasured by the EEC are displayed on theEICAS system in the cockpit. The primaryEICAS display will provide a full time tapedepiction of N1 setting and EGT. N2, fuelflow, engine oil and vibration parameters aredisplayed on the secondary EICAS ENGdisplay.

The vertical tape displays provide valuableinformation to the crew in the form ofnumerical and relative data. The numericalperformance of each parameter (N1 forexample) is displayed, as well as a verticaltape displaying performance relative to thewhole range. This also allows for cautionranges and maximum values to be displayedsimply.

If an engine is shut down in flight, primaryand secondary reporting information on theengine such as N1 and EGT will not bedisplayed because the power necessary forthe EEC to operate will not be available. Assuch, the EEC will cease functioning and nodata will be reported for that engine.

Normal operating range for engine variablesis displayed by the vertical white tape.Caution ranges are depicted by a horizontalamber bar. Warning ranges are depicted bya horizontal red bar.

If any indication reaches a caution orwarning range, it will change color toindicate that the caution or warning rangehas been entered. If the secondary CRThas been blanked, it will automaticallyactivate at the ENG page if an abnormalengine indication is detected.

Engine Vibrometers: Each engine usesvibrometers to monitor engine vibration inboth the N1 and N2 rotors. The rotor whichis producing the most vibration will beannunciated on the secondary EICASengine display. If a system fault prevents

the EEC from being able to determine whichrotor is causing the highest level of vibration,an average base vibration level for theengine will be displayed under the header ofBB, instead of N1or N2.

Engine Fuel System: Fuel is carried toeach engine via the fuel ducting systemwithin the wing and engine struts. Fueltransfers through the ducting under pressurefrom fuel pumps located within the fueltanks. The first stage engine fuel pump thenadds additional pressure to the fuel as it ispassed to the Fuel/Oil Heat Exchanger. Hotengine oil from the IDGs warms the fuel as itpasses through the Fuel/Oil HeatExchanger. Fuel is then passed through afilter to remove contaminants, and additionalpressure is added by the second stage fuelpump before the fuel passes through thefuel metering unit. The fuel metering unitadjusts fuel flow to the thrust requirementsdetermined by the EEC. Fuel flows, finally,through the engine fuel valve for distributionto the engine itself.

Fuel is allowed to flow to the engine as longas the engine fire shutoff handle is IN, theFUEL CONTROL switch is in the RUNposition and the engine fuel pumps areproviding fuel pressure. Fuel pumps willprovide pressure as long as the N2 rotor isturning.

Fuel flow to the engine is shut off any timethe N2 rotor stops turning, the FUELCONTROL switch is placed outside of RUN,or the fire handle is pulled OUT.

Fuel flow through the fuel system from tankto engines can be monitored by selectingthe FUEL synoptic on the secondary EICAS.Valve open/closed position can bemonitored, as well as flow through and crossfeed. Fuel flow is shown in green.

In the event of a loss of fuel pump pressureto an engine, each engine is able to suctionfuel only from it’s respecting wing tank.Indication of suction fuel feed is displayedon the secondary EICAS in amber.

Engine Starter/Ignition Systems: Eachengine has a bleed air powered startermotor connected to the N2 rotor of theengine. If no engines are currently



operating, bleed air is normally provided bythe APU, but may also be provided by aground unit with an air pressure bottle.

If bleed air pressure from a ground source isused to start an engine, bleed air ductpressure can be provided to the secondengine on the same side by closing thebleed duct valve on the opposite side fromthe engines being started. To produceenough duct pressure, it may be necessaryto advance the throttle on the runningengine to approximately 60% N1. Thrustcan be reduced to idle once the secondengine has started.

After starting both engines on the sameside, the bleed ducts can be opened toprovide bleed air pressure to start theremaining engines.

Bleed air is transferred to the starter motorwhen both the start valve and the enginebleed air valve are open. Both valves willopen automatically when the START switchis pulled. The START light will illuminate,indicating that the start valve has openedand bleed air is flowing to the engine.

Each engine has two igniters which operateindependently of one another, orsimultaneously depending on the position ofthe AUTO IGNITION selector. (Both orSingle.)

In order to reduce the likelihood ofinadvertent engine stalls, the ignition systemwill activate any time a start selector ispulled, or if engine nacelle anti-ice isselected ON. The ignition system will alsoactivate any time the CON IGNITION(Continuous Ignition) switch is selected ON,or the flaps are selected out of the UPposition.

The ignition system will deactivate whenanti-ice is selected off, or when the flaps arein the UP position, or when the fuel controlswitch is placed in the cutoff position,depending on the flight requirement.

Oil System: Each engine has anindependent fuel reservoir. Engine oil iscirculated through the engine underpressure to lubricate and cool engine parts.

The oil itself is cooled by passing the oilthrough a combination of Oil/Air HeatExchanger and a Fuel/Oil Heat Exchanger.This process both provides heat to the fuelsystem and cooling to the engine oil system.

Engine oil temperature and pressure aredisplayed on the secondary EICAS ENGdisplay.

Reverse Thrust Capabilities: Each engineis capable of providing both forward andreverse thrust, depending on the flightsituation and crew need. Reverse thrust isavailable while the aircraft is on the ground.

Each engine has an independent,hydraulically actuated fan air reverser. Thehydraulic pressure needed to actuate thereverser comes from the associated enginedriven hydraulic system, and as such, lossof the hydraulic system will cause loss of thehydraulics required for reverser operation.

Actuation of the thrust reverser can onlyoccur when the throttles are in the idleposition. Actuation causes the reversersleeve to move aft, exposing a series ofshroud vanes designed to redirect fan airforward with the help of fan blocker doorswhich redirect fan air flow into the vanesrather than through the engine.



Actuation of the reverser system willdisengage the autothrottle.

The primary EICAS will display REV inamber next to the engine instrumentation toindicate actuation of the reversers. TheREV annunciation will remain amber whilethe reversers are in transit to the deployedposition, or when they are in transit to thestowed position. When REV is annunciatedin green, it is safe to apply reverse thrust.

An amber REV indication in flight indicatesthat the reverser sleeve has released fromthe stowed position and hydraulic pressureis being used to return the sleeve to thestowed and locked position.

During the application of reverse thrust, theEEC will automatically monitor engineperformance, and calculate a maximum N1and fuel flow for engine reverse thrust inorder to prevent exceeding any enginelimitations during the reverse thrust.



ENGINE START/CONTROL SWITCHES

Fuel Control Switch: [Run] allows fuel flowto the associated engine.[Cutoff] discontinues fuel flow and ignition.

Fire Warning Lights: Fire warning lightsare located within the fuel control switchpost to indicate a fire. Light extinguishes iffire is no longer detected.

ENGINE START Switches: Pulling initiatesengine start by opening the start valve,engine bleed air valve and arming theappropriate ignition system. At 50% N2, theswitch returns to the run position, whichcloses the start valve and engine bleed airvalves.

STBY IGNITION Selector: [NORM] AC busprovides power to the selected igniter.Standby bus will automatically providepower if main bus fails.

AUTO IGNITION Selector: Allowsselected igniter to operate automatically if anengine is being started with N2 less than50%, or if flaps are out of UP or if enginenacelle anti-ice is selected ON.

AUTOSTART Selector: Allows functioningof autostart, which will monitor engineperformance and automatically start/re-startengines during engine startup and in flight.

IGNITION CON Switch: [ON] Igniterselected on AUTO IGNITION switch will

operate continuously as long as the FUELCONTROL switches are out of CUTOFF.



PRIMARY / SECONDARY EICAS ENGINE DISPLAYS

N1 Display Indicator: Displays actual N1.Changes to red if at N1 limit.

Reference Annunciation: Indicatesreference N1 limit for current thrustreference mode. Will indicated REV inamber when reverser is in transit. REVchanges to green when reverser deployed.

EGT Display Indicator: Displays actualEGT. Displays white while in normaloperating range, amber at max continuouslimit and red at maximum start or takeoffEGT limit. During takeoff/go around, changeto amber is inhibited for five minutes.

Maximum N1 Limit: (Red) Max allow N1.

Reference N1 Indicator: (green) IndicatesN1 limit for the thrust mode. Indicates[magenta] target N1 as commanded by theFMC when VNAV is engaged.

Command N1 Position: (white)Indicatescurrent throttle position and N1 that willresult from this throttle position.

.

Thrust Mode Annunciation: Indicatescurrent selected thrust mode from whichreference thrust limits are being set by theFMC. Possible settings are:

TO Maximum Takeoff ThrustTO 1 Derate 1 Takeoff (-5%)TO 2 Derate 2 Takeoff (-15%)D-TO Assumed Temperature TakeoffD-TO-1 Derate 1 Assumed Temperature

TakeoffD-TO-2 Derate 2 Assumed Temperature

TakeoffCLB Maximum Climb ThrustCLB 1 Derate Climb 1 SelectedCLB 2 Derate Climb 2 SelectedCON Maximum Continuous ThrustCRZ Maximum CruiseG/A Maximum Go-Around Thrust

Assumed Temperature: (Not shown here)Indicates assumed temperature as enteredinto FMC.

Relative Position Indicators: Rising tapedisplay (white on EICAS) indicates relativeposition of current setting relative to entireavailable range.



NAI Annunciation: Nacelle Anti Iceannunciation [green] indicates that nacelleanti ice is selected ON.

WAI Annunciation: (Not shown here)Wing Anti Ice annunciation [green] indicatesthat wing anti ice is selected ON.

Fuel Flow Indicator: Displays fuel flow in1,000lbs / hour

Oil Pressure Indicator: Displays oilpressure in digital and scale format.

Oil Temperature Indicator: Displays oiltemperature in digital and scale format.

Oil Quantity Indicator: Displays oil quantityin digital format.

Vibration Source: Indicates the vibrationsource displayed. Displays source with thehighest level of vibration.

[N1] – N1 rotor vibration.[N2] – N2 rotor vibration.[BB] – broadband vibration: source cannotbe determined.



ENGINE THRUST REVERSER ACTIVATION DIAGRAM

REVERSERSTOWED

REVERSER UNLOCKED(IN TRANSIT)REV displayed in amber on EICAS

REVERSER DEPLOYEDREV displayed in green on EICAS



FIRE DETECTION / SUPPRESSION SYSTEMSOverview: The 747-400 uses acomprehensive system of fire detection andsuppression for all four engines, the APUand the cargo spaces. Fire detection (butnot suppressions) is provided for the landinggear bays.

The fire detection system is automaticallytested when electrical power is first suppliedto the aircraft, and fire detection remainscontinual until power is removed.

The fire detection system used in theengines, APU and cargo spaces consists ofa double loop system for redundancy. Thesystem logic will automatically reconfigureitself for single loop operation in the event asystem fault is detected in one of the twosystems.

Fire/Overheat Indications: Fire warningsare related to the crew through activation ofthe master warning light, individualilluminated red fire shutoff handles for eachof the engines and the APU, as well as theforward and aft cargo compartments.Engine fires will also cause a red warninglight to illuminate in the FUEL CONTROLswitch for the affected engine, and redwarning indications on the primary EICASwill become active.

When activated, the fire warning bell will ringintermittently, so as not to severely disruptcrew communications in a fire emergency.The fire bell will ring for one second, thenpause for ten seconds before ringing again.The fire warning bell can be silenced byextinguishing the fire or pushing the masterwarning light once.

Crew rest area smoke detectors, as well aslavatory smoke detectors, will providecockpit warning signals.

Overheat indicators are cautionary in nature,and will cause the master caution light toilluminate in conjunction with the associatedcautionary EICAS message. An attentionalert beeper will sound rapidly, four times inone second to indicate an overheat systemfault.

In order to prevent crew distraction duringcritical phases of flight, the fire warning belland master warning light are inhibited whilethe aircraft is between V1 and 400 feetduring takeoff, or twenty five seconds,whichever is longer. All other warningmethods will still operate during this blackoutperiod

Cargo Compartment FireDetection/Suppression: Fire detection inthe forward and aft cargo areas of theaircraft is handled by two pairs of flowthrough type smoke detectors. The flowthrough smoke detectors use a pneumatictype venturi to induce flow through over apair of optical sensors.

In order to trigger a FIRE CARGO warningon the primary EICAS (with associatedmaster warning light and sirens) bothsensors in a single smoke detection modulemust detect the presence of smoke.

Fire suppression is provided by four chargedfire bottles located in the center of theaircraft. The bottles are armed by pressingthe CARGO FIRE EXTINGUISHINGARMED switch on the fire suppression panelThis will arm all four fire suppression bottlesto discharge.

The ducting system which connects the fourfire suppression bottles is designed so as toallow all four bottles to be discharged into asingle cargo compartment.

The fire suppression system is activated bypressing the fire suppression switch on thefire suppression control panel. Pressing thisswitch will cause bottles A and B to fullydischarge into the cargo compartment wherethe smoke was detected.

After approximately 30 minutes bottles Dand C will begin to discharge into the cargospace under a metered flow of suppressant.Combined, the four fire suppression bottleswill provide a total of 195 minutes of firesuppression to a single cargo compartment.It is not possible to discharge to multiplecargo compartments.



If the discharge switch is pushed while theaircraft is on the ground, all four bottlesdischarge immediately, however bottles Cand D still maintain a metered flow into thetarget compartment.

If the fire suppression process is startedwhile airborne, bottles C and D willautomatically discharge when the air groundsensor determines that the aircraft haslanded.

Lower Cargo Fire Switches: The lowercargo fire switches are used for arming arespective compartment should a firewarning be generated.

The FWD switch, when pushed, displays anARMED indication and accomplishes thefollowing:

• Turns off Pack 3.• Turns off all fans.• Arms respective squibs in the cargo

extinguisher bottles.• Configures equipment cooling to

override mode and turns off airflowand heat into the forwardcompartment.

The AFT switch, when pushed, displays anARMED indication and accomplishes thefollowing:

• Turns off Pack3• Turns off all fans.• Arms respective squibs in the cargo

extinguisher bottles.• Configures equipment cooling to

override mode and turns off airflowand heat into the forwardcompartment.

• Turns off aft cargo heat.

APU Fire Detection/Suppression: A dualloop fire detection system is used to firedetection in the APU compartment itself.Although the APU uses a dual loop firedetection system, only one of the two loopsmust detect a fire in order to trigger a fireindication in the cockpit. This varies fromthe fire detection parameters used forengines because of the location of the APUin relation to critical aircraft control system.

Fire detection by either loop will trigger a firewarning in the cockpit via a master cautionlight and a FIRE APU indication on theprimary EICAS.

APU Fire/Shutoff Handle: Illuminates if afire is detected in the APU. Pulling handleinitiates shutdown of APU, closes fuel valve,bleeds and arms the fire suppressionsystem.

APU BTL DISCH Light: Indicates lowpressure in the APU fire extinguisher bottle.

Using Fire Handles: To realistically modelthe steps required to activate engine/apu firesuppression, we have modeled the need forthe pilot to pull the engine/apu firesuppression handle OUT in order to activatethe suppression mechanisms.

To model pulling the fire handle OUT, wehave used similar techniques for both the 2Dand Virtual cockpit:

Engine fire handles• 2D: Click at the base of the handle

to pull.• VC: Click on the panel “behind” the

handle to pull.

APU Fire Handles:• 2D: Click on the far right side of

handle to pull• VC: Click on the panel “behind” the

handle to pull.

Engine Fire Detection/Suppression:Engine fire detection is provided through theuse of a double loop fire detection systemwhich monitors for engine/nacelle fire andoverheat conditions. In order for a fire oroverheat warning to be tripped, both loops ofthe fire/overheat detection system must trip.



Fire suppression for the engines is availablefrom two fire suppression bottles installed ineach wing. The bottles on the left wingprovide fire suppression for engines 1 and 2,while the bottles in the right wing provide firesuppression for engines 3 and 4.

Engine fire suppression is activated bypulling the associated engine fire handle andtwisting to discharge either the A or B firebottle. The fire warning will extinguish whenthe fire is no longer detected. If greaterextinguishing capability is needed, thesecond fire bottle can be used by twistingthe fire handle in the opposite direction.

Engine Fire/Shutoff Handles: Illuminatesupon fire detection in associated engine.Pull handle to close engine fuel valves andbleeds, disengage engine driven functionsand hydraulics and arm fire bottle. Twistinghandle activates fire suppression system.

BTL DISCH Lights: Indicates low pressurein the associated fire extinguisher bottle.

Lavatory Fire Detection/Suppression:Each lavatory has installed a single,standard operation smoke detector whichemits an audible signal in the event smokeis detected.

Fire suppression is provided by one dualnozzle, heat activated Halon fire

extinguisher located under the sink. Theextinguisher operates independently of thesmoke detector, and is independent ofaircraft power in order to operate. Theextinguisher will automatically discharge onestream of Halon directly into the garbagebin, the second will be discharged in thearea immediately underneath the sink.

Wheel Well Fire Detection: The WheelWell fire detection system consists of asingle loop detector in each main gear wheelwell. If a fire condition in any main gearwheel well is sensed by a detection loop, afire warning is activated. There is noextinguishing system installed for fire in thewheel wells.

FIRE/Overheat Testing: In addition to thecontinuous testing of engine and APUdetection systems, testing of all dual loopfire/ overheat detectors and cargocompartment smoke detectors occursautomatically when electrical power isinitially applied to the aircraft. Pushing theFire/Overheat Test switch manually initiatesthe tests. The EICAS warning messageTEST IN PROG is displayed when the test ismanually initiated. On the actual aircraft it isnecessary to hold the test switch in whileconducting the Fire/Overheat test. Thisprocedure is not practical within MSFS sinceit is necessary to check the state oflights/warnings on three different panels, sowe have instead modeled this switch as a 10second test process that will run once theswitch is pressed.

After pressing the switch, check forfire/warning lights on the overhead panel,main panel and throttle console.

At the conclusion of the Fire/Overheat test,either a FIRE TEST PASS or a FIRE TESTFAIL message will be displayed.

Importance of Procedures: It is vitallyimportant that the appropriate Abnormalprocedures be followed in the event of afire/overheat warning in flight. Failure tofollow correct procedure may lead toadditional damage to the aircraft and or lossof control in flight.



.OVERVIEW OF ENGINE FIRE SUPPRESSION SYSTEM

(Left and Right Wing Identical)



FIRE CONTROL SYSTEM EICAS MESSAGES:FIRE CARGO AFT Smoke detected in the lower aft cargo compartmentFIRE CARGO FWD Smoke detected in the lower forward cargo compartment

FIRE ENG 1,2,3,4 Engine fire condition detected, or airframe vibrations withabnormal engine indications.

FIRE WHEEL WELL Fire indication in one of the main gear wheel wells.

FIRE APU APU Fire condition detected

>FIRE TEST PASS Indicates manual fire test has passed.

>FIRE TEST FAIL Indicates manual fire test has failed. (Displays with related failuremessages.)

>TEST IN PROG Indicates manual fire test in progress

EQUIP COOLING Automatic equipment cooling function has failed, or equipmentcooling air supply temperature is excessive, or air flow rate to theflight deck Electronics and Equipment bay is low, or smoke isdetected in the equipment cooling exhaust air, or ground exhaustvalve not in commanded position.

>SMOKE DR 5 REST Smoke is detected in door 5 crew rest area. Recirculation fansautomatically shut down and air conditioning packs switch to HIFLOW.

>BOTTLE LOW APU APU fire extinguisher bottle pressure is low. (Associatedannunciator on overhead panel as well.)

>BTL LOW L (R) ENG A B Engine fire extinguisher bottle A or B pressure is low.(Associated annunciator on overhead panel as well.)

>CARGO DET AIR Insufficient airflow is available for smoke detection.

>CGO BTL DISCH On the ground: A cargo fire bottle pressure is low.In flight: Fire bottle A and B are discharged.

>DET FIRE APU APU fire detection loops A and B have both failed.

>DET FIRE/OHT 1,2,3,4 ENGINE fire/overheat detection loops A and B have both failed.

>SMOKE LAVATORY Smoke is detected in a lavatory.



FLIGHT CONTROLSOverview: The flight control system on the747-400 is powered by the four independenthydraulic systems. Each system provideshydraulic power to the flight controls in orderto provide for maximum redundancy.

The primary aircraft controls, rudder, aileronand elevator, are supplemented byhydraulically powered speedbrakes, spoilersand a hydraulically adjustable horizontalstabilizer. The wing trailing edge flaps arealso hydraulically powered. The leadingedge slats are powered pneumatically.

The flight controls use a computergenerated tactile feedback to simulatecontrol pressure to the yoke. Due to thelarge size of the flight control surfaces, itwould not be feasible for direct controlfeedback, as significant control pressureswould be required by the crew at highairspeeds. The flight controls are designedsuch that the aircraft will respond in a similarfashion to control input regardless of speed,weight and center of gravity.

All flight control surfaces can be controlledby the autopilot just as they are controlled bythe crew, with the exception of spoilers andspeedbrakes which must be manuallyactivated. Provision is made for additionalprotective systems, such as a flap load reliefsystem to prevent damage to the flap jacksand fairings.

Elevators: There are four elevator surfaceson the 747-400, two on each side of theaircraft. The inboard elevator surfacesreceive hydraulic power from twoindependent hydraulic systems each andreceive control input directly from the controlcolumn. The outboard elevator surfaces aremechanically linked to the inboard surfaces,and receive hydraulic power from oneindependent hydraulic source each. Controldeflection is used to actively pitch the noseof the aircraft up or down. Trim control isprovided by the horizontal stabilizer.

Outboard Left: Hydraulic System 1.Inboard Left: Hydraulic System 1/2Inboard Right: Hydraulic System 3/4Outboard Right: Hydraulic System 4

Elevator Position Indication: Thesecondary EICAS STAT page contains adisplay featuring indexing for both elevators.

Horizontal Stabilizer: The horizontalstabilizer is moved by hydraulic powersupplied by systems 2 and 3. The hydraulicmotors drive a jackscrew actuator whichcauses the stabilizer to move up or down.Control of this system is via the horizontalstabilizer trim switches in the cockpit.

Stabilizer trim position is shown in thecockpit on the stabilizer trim positionindicator. The green band will indicate thenormal trim range setting for takeoff.

Autopilot control of the stabilizer trimmechanism is via electric control of thehydraulic actuators, allowing the AFDSsystem full access to the stabilizer trimrange.

Important Note on Trimming: Anautomatic override system is in place whichwill disconnect any trim input (either manualor via the Autopilot if the crew placespressure on the control column in theopposite direct of the trim input. If you areexperiencing problems with trim inputs,ensure that your controller is properlycalibrated.

Ailerons: Each of four ailerons receiveshydraulic power from two independent



hydraulic sources each. Loss of any onesystem will not impair the ability of the crewto deflect the ailerons through their full rangeof travel.

Aileron One: Hydraulic systems 1/2Aileron Two: Hydraulic systems 1/3Aileron Three: Hydraulic systems 2/4Aileron Four: Hydraulic systems 3/4

Two sets of ailerons are provided on eachwing. The outboard ailerons areautomatically locked out when the flaps arein the UP position and airspeed increasesbeyond 235 KIAS or .52 Mach. Reducingspeed below these threshold limits, orselecting flaps out of UP will restoreoutboard aileron function.

The inboard aileron set does not lock out inany speed or configuration.

If necessary, aileron trim can be applied inorder to maintain wings level flight. Theproper procedure is to provide control inputsufficient to maintain the desired bank angle,then add or subtract trim until controlpressure is no longer required, and the flightcontrols are level from the perspective of thepilot. This will prevent an inadvertent rolltendency caused by spilt flap conditions orengine out situations.

When the airplane is parked and hydraulicsare depressurized, it is not uncommon to theinboard ailerons deflected downward fromtheir normal, neutral position. The outboardailerons should not normally exhibit thisbehavior.

Spoilers: Each wing has 6 spoilers. Thetwelve total spoilers are numbered from leftto right, 1 through 6 on the left wing and 7through 12 on the right wing.

The four inboard spoilers on each wing(Spoiler plates 3,4,5,6 on the left side, and7,8,9,10 on the right side) function asspeedbrakes in flight.

On the ground, all six spoiler panels on eachwing function as ground spoilers. Thespeedbrake and ground spoiler functions arecontrolled with the speedbrake lever.

Spoiler mixers combine behaviors of the rollcontrol and spoiler functions to provide bothspeedbrake and spoiler control whennecessary.

Spoiler Position Indication: The positionof one spoiler panel on each wing isdisplayed on the EICAS secondary enginedisplay. On the left wing, the position of thefourth spoiler panel in from the wingtip isdisplayed. This panel functions as a flightspoiler, speedbrake and ground spoiler. Onthe right wing, the position of the outboard-most spoiler panel is displayed. This panelfunctions as a flight spoiler and groundspoiler only. Therefore, speedbrakeextension is not indicated on the right wingspoiler position indicator in flight.

Speedbrake Handle Function: Thespeedbrake lever input is limited to the mid-travel FLIGHT DETENT position by anautomatic stop in flight.

The speedbrakes should not be used withtrailing flaps extended past flaps 20 in orderto prevent excessive wear on the flap jackmechanisms.

Upon touchdown, all twelve spoilers functionas lift canceling devices and will fully deflecton manual command of the speedbrakehandle, or automatically if the speedbrakehandle is placed in the ARMED positionprior to touchdown.

The ground spoilers will activateautomatically upon landing when all threeconditions are met:

• The Speedbrake lever is in the ARMposition.

• Thrust levers 1 and 3 are near theclosed position.

• The main landing gear touch down.

The speedbrake lever will be automaticallydriven to the UP position, extending thespoilers if the following conditions are met:

• The speedbrake lever is in theDOWN position.

• Thrust levers 1 and 3 near theclosed position.

• The main landing gear are on theground.



• Reverse thrust is selected onengines 2 or 4.

This provides automatic ground spoilerfunction for Rejected Take Off conditionsand provides a backup to the automaticground spoiler function for landing if thespeedbrake lever is not armed during theapproach.

For Go-Around protection or rejectedlandings, if thrust lever 1 or 3 is advancedfrom the closed position, the speedbrakelever is automatically driven to the DOWNposition. This function occurs regardless ofwhether the ground spoilers wereautomatically or manually extended.

The speedbrake lever can always bemanually extended or returned to the downposition.

In the event of a hydraulic system failure,the spoilers and speed brakes will lock in thedown position in order to prevent spoilerfloat and the loss of associated lift.

Rudder: Yaw control is provided by tworudder devices; the upper rudder and lowerrudder. Each rudder control surface ispowered by two independent hydraulicsystems, and accepts control input via arudder ratio changer which modulatesrudder deflection based on airspeed.

Rudder trim is applied by deflecting therudder manually to the desired position, thenadding rudder input until the control pedalsreach a new neutral position. Electricalcontrol of the hydraulic actuators on therudder will deflect the rudder thecommanded amount.

The rudder function is supplemented by twofully independent yaw damper systemsdesigned to improve aircraft directionalstability, and to improve aircraft roll rate andturn performance during turns.

The yaw dampers receive hydraulic controlfrom hydraulic systems 2 and 3. Yawdamper deflections are applied directly tothe rudder control surfaces in proportion toany turn or yaw tendencies detected by theIRS yaw sensors located in the nose and tailof the aircraft.

Yaw damper rudder input cannot be sensedby the crew via the rudder pedals, and willnot interfere with crew rudder input.



FLIGHT CONTROL CONFIGURATION

Leading Edge Slats:

Inboard Spoilers (Speed Brakes):

Inboard Aileron:

Outboard Spoilers:

Outboard Aileron:

Inboard Trailing Edge Flaps:

Outboard Trailing Edge Flaps:

Horizontal Stabilizer:

Inboard Elevator:

Outboard Elevator:



Leading and Trailing Edge Flaps: Theleading and trailing edge flaps are operatedby either a primary drive system or asecondary drive system. The primary drivesystem is normal for all phases of flightunless a system fault has been detectedwhich prevents the primary system fromfunctioning. The secondary system canthen be used to change flap configurations.

Flap movement is managed by threeindependent flap control units which provideflap position information to the EICASdisplay, provide for flap load relief ifrequired, and prevent asymmetric flapdeployment.

Trailing edge flaps are driven by hydraulicpower, while the leading edge flaps aredriven by pneumatic power. Flap position iscommanded by the flap position handle.

If the flaps fail to move to, or reach thecommanded position, the flap control unitswill automatically switch to the secondaryactuation and display mode for the affectedflap group. When secondary mode isactuated, the flap drive mechanisms aredriven using electric power. Flap groups willswitch to secondary operation in symmetrybetween the wings, which preventsasymmetric flap deployment.

Secondary flap deployment is significantlyslower than primary flap deployment.

Due to limitations within the simulator, it isnot possible to adequately model thesignificant time difference between primaryand secondary flap actuation

When any trailing edge flap groups switch tosecondary deployment due to a hydraulicpressure failure, they will automaticallyreturn to primary deployment if hydraulicpower is restored. If the trailing edge flapsare switched to secondary mode whilehydraulic power is available, however, theywill not return to primary mode until theyhave been fully retracted and the hydraulicmode system automatically resets.

Leading edge flaps operating in secondarymode will always remain in secondary mode

until reaching the commanded flap position,regardless of whether or not pneumaticpower becomes available.

An alternate flap deployment method isavailable to the crew which allows all flaps tobe electrically driven. When the alternateflaps actuator is set to ALTN, the flapposition command handle becomesinoperative, and flap setting needs to bedetermined by commanding the flaps ALTNdrive up or down as needed.

Trailing Edge Flaps: The trailing edgeflaps are comprised of an inboard and anoutboard set on each wing. All four sets oftrailing edge flaps are driven by separatehydraulic systems. The outboard flaps aredriven by systems 1 or 4, while the inboardtrailing edge flaps are driven by systems 2or 3.

In the event of the loss of any hydraulicsystem, that trailing edge flap set willautomatically revert to secondary flapdeployment.

A flap load relief system, managed by theflap control units protects the trailing edgeflap system from being operated atexcessive airspeeds while in the flaps 25 orflaps 30 range. At airspeeds in excess of178 knots, the flaps control units willreposition the flaps from the 30 position tothe 25 position. At airspeeds in excess of203 knots, the flaps control units willreposition the flaps from the flaps 25position to the flaps 20 position.

If the flaps are being deployed using thesecondary or alternate system, flap loadrelief is not available.

Leading Edge Slats: Each wing has threeseparate sets of leading edge slats. Thesegroups are geographically divided on thewing by the wing pylons, and are describedby their location on the wing. The flapgroups are OUTBOARD, MIDSPAN andINBOARD respectively.

Each wing has a total of fourteen leadingedge slats. The eleven outboard and mid-span slats are variable camber flaps, while



the three inboard slats are of the Kruegertype.

The leading edge slats deployment andretraction schedule is tied to the flapcommand positions of flaps 1 and flaps 5.With the flap command handle is movedfrom UP to 1, the inboard and mid-spanslats deploy. When the command handle ismoved from flaps 1 to flaps 5, the outboardslats deploy.

For all leading edge slats, there is only anextended and retracted position. There isno mid range position.

If the ALTN flap deployment method isrequired due to a system failure or hydraulicfailure, all leading edge flap groups deploysimultaneously. Crews are cautioned thatthe airplane may tend to balloon at the flaps1 setting due to the abnormal deployment ofthe outboard leading edge slats group at thissetting.

When reverse thrust is selected aftertouchdown, the inboard and mid-span slatsretract in order to dump lift from the primarylifting surfaces of the wing, as well as toimprove the structural life of the leadingedge devices.

Flap Position Indicators: Flap indicationsare provided on the primary EICAS display,and are driven directly by the flap controlunits and the associated flap positionsensors located within the flap systems.

During normal operation, the flap positionindicator is comprised of a single verticaltape with a horizontal band to depict thecommand flap setting and a white verticaltape to depict current flap position. Onlanding, the leading edge slat retractionsequence will cause the flap positionindicator to show flaps are in transit. This isnormal.

If any fault is detected which requires theactivation of the secondary or alternate flapsystems, a larger, expanded flap positionindicator is displayed. This indicator willprovide graphically, information on thecurrent position of each flap subgroup, aswell as any failure information related to thepositioning of flap or slat groups. An amberX drawn in the position of any flap groupindicates failure of the flaps position sensor.

Leading Edge Flap Groups:

Trailing Edge Flap Groups:



FLIGHT CONTROLS EICAS MESSAGES:STAB TRIM UNSCHED Uncommanded stabilizer motion is detected and automatic

cutout does not occur, or alternate stabilizer trim switches areused with the autopilot engaged.

AILERON LOCKOU Aileron lockout actuator position disagrees with commandedposition.

FLAPS CONTROL Flap control units are inoperative, or alternate flap mode isarmed.

FLAPS DRIVE One or more flap groups have failed to drive in the secondarycontrol mode, or an asymmetry condition is detected.

FLAPS PRIMARY One or more flap groups are operating in the secondary controlmode.

>FLAP RELIEF Flap load relief system is operating.

>FLT CONT VLVS Flight control valve is closed.

RUD RATIO SNGL Rudder ration changer has failed.RUD RATIO DUAL

SPEEDBRAKE AUTO Fault detected in the automatic ground spoiler system.

>SPEEDBRAKES EXT Speedbrakes are extended at an inappropriate flight condition.(Throttles forward of idle.)

STAB GREENBAND Nose gear pressure sensor disagrees with computed stabilizertrim green band. (The airplane is not correctly trimmed fortakeoff.)

>STAB TRIM2 3 Stabilizer trim automatic cutout has occurred or stabilizer trimswitch in CUTOUT or trim commanded and respective actuatorfailed to function.

>YAW DAMPER UPR LWR Associated yaw damper failure or respective yaw damper switchis OFF



FUEL SYSTEM

Overview: The fuel system on the 747-400is designed to provide the maximumcapacity possible in order to increase aircraftrange, hold time, and service capabilities.

The fuel system is capable of holding 57,164gallons of Jet-A fuel. At a fuel density of6.7lbs, this provides a maximum fuel weightof 382,600 pounds.

Fuel is carried in four main tanks, a centerwing tank, two wing reserve tanks, and anadditional tank located within the horizontalstabilizer. Any engine can draw fuel fromany fuel tank on the aircraft, however fuelcan only be suction fed from the main wingtanks in the event of fuel pump failures.

A fuel jettison system is available in theevent fuel weight needs to be discharged. A“Fuel to Remain” level system is installed.

When the fuel pumps are switched OFFprior to engine start, each main tank switchshould display a low pressure light. Theselights will be extinguished on the override,center tank and stabilizer tank switches.

The automated fuel loading distributionsystem logic distributes fuel to minimizewing bending.

The fuel system on the PMDG 747-400 iseasily the most complex part of the airplanefrom a behavior and logic standpoint. Thisportion of the airplane took more than 10weeks to program because of its complexityand automation behaviors, and because ofthe severe limitations imposed on fuel usageby the primitive fuel tank model used byMicrosoft Flight Simulator 9.

In order to accurately simulate the fuelsystem on the 747-400, it was necessary todevelop tools to allow the user to change thefuel load in the airplane without using thedefault MSFS fuel menu.

To change the fuel load in the airplane, usethe PMDG/OPTIONS/VARIOUS menu, andscroll your mouse wheel over the fuel figure

to increase or decrease the figure to suityour needs.

When you then hit OK the fuel requestedwill be loaded on the aircraft, properlyconfigured for the correct tanks based uponthe quantity loaded.

The PMDG 747-400 fuel system maintains aperpetual fuel figure, so leaving thesimulator and returning (at the end of aflight, for example) will instruct the simulatorto reload the fuel-on-board figure from whenyou left the simulator.

We recommend that under no circumstanceshould you use the default MSFS fuelloading menu, as this will createunpredictable and undesired results with theairplane.

Fuel Pump Systems: Each main tank andthe stabilizer tank have two AC-powered fuelboost pumps to provide fuel under pressureto the engines. In addition, main tanks 2and 3 (inboard tanks) and the center wingtank each have two AC powered overridefuel jettison pumps.

Each fuel pump has an actuator switchlocated on the overhead fuel control panel inthe cockpit. When AC power is supplied tothe aircraft turning the APU start selector toSTART will automatically activate the maintank 2 aft fuel boost pump. In the event ACpower is not available, a DC-powered fuelboost pump will provide fuel pressure. TheAPU always draws its fuel supply from maintank 2.

When either of the center wing tank fuelpumps detects low fuel pressure, a centerwing tank fuel scavenge pump isautomatically activated. This pump willscavenge the remaining fuel in the centertank and pump it into main tank 2.

Fueling: Fueling stations for the aircraft arelocated on either wing, between the twowing engines. Each station contains twoidentical fueling couples and manual shutoff



valves. Electrical power for fuelingoperations must be provided by the APU,aircraft battery or an external power source.

The left wing fueling station contains afueling control panel just outboard andadjacent to the left wing fueling station. Thispanel contains all controls necessary fordistributing fuel properly and according tothe dispatch request.

Manual magnetic-type dripless fuel quantitymeasuring sticks are located in all fueltanks.

A vented surge tank is located near the tip ofeach wing. The vent is a NACA type venturiwhich will provide positive pressure on thefuel tanks during cruise.

If the stabilizer tank fuel pump is switchedON during fueling operations, this may leadto transfer of fuel destined for the stabilizertank. This is the only effect that should beanticipated if fuel pumps are active duringfueling, and can be prevented by selectingthe stabilizer tank fuel pump OFF prior tofueling.

Fuel Management: Fuel management logicon the 747-400 is highly automated in orderto reduce pilot workload. The automatedsystem logic is also designed to reduceairframe flexing and wing structure stressdue to fuel loading.

Heavier fuel loads requiring use of thecenter wing fuel tank are handled differentlythan lighter loads not requiring center tankfuel.

Main Tank Fuel Pumps: Each main tankcontains two AC powered fuel pumps thatare each capable of providing adequate fuelfor one engine operating at takeoff power, ortwo engines at cruise power.

On the secondary EICAS fuel page, eachpump is depicted with an icon. The color ofthe icon is descriptive of the pump’s currentstate.

Green: Pump is selected active and has nofaults detected, even if it is not supplyingfuel to an engine.

Blue: Pump is selected active, but basedupon FMCS logic it has been placed instandby mode.

Amber: A fault is detected in the pump or thepump’s activity disagrees with the FMCSlogic.

White: The pump is selected off.

Main Tank 2 and 3 Override/JettisonPumps: Main tanks 2 and 3 also containtwo AC powered override/jettison pumpswhich can operate to a standpipe fuel levelof approximately 7,000lbs remaining in theassociated tank.

Each override/jettison pump can provideadequate fuel to two engines during takeoffor cruise conditions.

Override/jettison pumps 2 and 3 areinhibited from operating when pressure isdetected from both Center Wing Tankoverride/jettison pumps. Output pressure ofthe override/jettison pumps is greater thanthe output of the main fuel pumps.

Center Wing Tank Fuel Pumps: TheCenter Wing Tank contains two AC poweredoverride/jettison pumps. Each overridejettison pump can provide adequate fuel fortwo engines during takeoff or cruiseconditions. The output pressure of theoverride/jettison pumps is greater than theoutput pressure of the main fuel pumps.With main fuel pumps and override/jettisonpumps operating simultaneously, theoverride/jettison pumps will provide fuel tothe engines. However, one CWToverride/jettison pump does not overridemain tank 2 and 3 override/jettison pumps ormain tank 1 and 4 main fuel pumps.

Crossfeed Manifold and Valves: Acommon fuel manifold connects all maintanks and the CWT. There are fourcrossfeed valves in the fuel manifold.

Crossfeed valves 1 and 4 are manual andwill remain set in whatever position iscommanded by their respective switches.

Crossfeed valves 2 and 3 are automatic,and while responding to position commandsfrom the switches, they will respond



programmatically to the Fuel ManagementSystem Cards in order to direct fuel flowcorrectly for specific flight modes.

For example, before takeoff if the crossfeed2 and 3 valves have been commanded openbut the fuel control panel switches, thevalves will close when takeoff flaps areextended. This provides tank to engineoperation for engines 2 and 3.

Following flap retraction, the valves willreturn to the switch commanded position.

If the Crossfeed valve 2 and 3 switches areset to the closed position, there is noautomatic control for these valves and theywill remain closed.

Reserve Tank Transfer Valves: Eachreserve tank contains two transfer valves.These valves automatically transfer fuel bygravity feed from the reserve tank into theirrespective inboard main fuel tank when themain tank 2 or 3 fuel quantity decreases to40,000lbs.

This feed activity is depicted on thesecondary EICAS fuel display.

Main Tank 1 and 4 Transfer Valves: Maintank 1 and 4 each contain one transfer valvewhich allows fuel to transfer by gravity fromthe outboard main tank to it’s respectiveinboard main tank. Each valve allowsgravity transfer to approximately 7,000lbsremaining in the outboard main tank.

Manual Operation: Manual operation ofthese valves is available while the aircraft ison the ground, primarily for maintenancepersonnel. This function is not modeled inthe PMDG 747-400.

Automatic Operation: Automatic operation ofthese valves occurs during fuel jettison.When either main tank 2 or main tank 3 fuelquantity decreases to 20,000lbs duringjettison, both main tank 1 and 4 transfervalves are automatically opened by the FuelManagement System Cards.

Operating With Center Wing Tank Fuel: Iffuel is contained in the center fuel tank, allcrossfeed valves should be opened prior toengine start. In addition all override/jettison

and main tank boost pumps should beactivated for tanks containing fuel.

Control of the fuel system is handled in anautomated fashion by the Fuel SystemManagement Cards. The FSMCs willmonitor flap setting and adjust the fuelsystem logic to provide a redundant fuelsupply during takeoff in case of electrical orfuel pump system failures.

The FSMCs will close crossfeed valves 2and 3 when takeoff flap settings aredetected on the ground. The center wingtank will provide fuel to engines 1 and 4,while engines 2 and 3 will receive fuel fromtheir respective main tank. In thisconfiguration, the override/jettison pumps fortanks 2 and 3 will be inhibited fromoperating.

When flaps are retracted, the FSMCsautomatically re-open crossfeed valves 2and 3, and the center tank will now providefuel to all four engines.

The FSMCs will monitor the fuel level of thecenter wing tank. When the center wingtank fuel quantity has decreased to80,000lbs fuel will be transferred from thestabilizer tank to the center wing tank.

When this fuel transfer is completed, thecrew will receive an EICAS advisorymessage indicating FUEL PUMP STAB.This indicates that the AC-powered fuelpumps in the stabilizer tank have detected



low fuel pressure. Stabilizer pump switchesshould be selected off when the tankindicates empty.

When the center wing tank fuel quantity isdecreased to approximately 2,000lbs, theEICAS advisory message FUEL OVRD CTRwill be displayed, indicating one of theoverride/jettison pumps has detected lowoutput pressure. The center wing tankoverride/jettison pumps should be selectedOFF at this time. The center wing tankscavenge pump will begin operatingautomatically to transfer remaining fuel tomain tank 2. This pump will operate until itdetects low output pressure, indicating thatthe center wing tank is now empty, or until120 minutes have passed.

Note: When Center Wing Tank quantity hasdropped below 5,000lbs there are occasionswhen the center wing tank pumps cannotprovide full override of the outboard maintank pumps. As a result a shared flowsituation results with approximately 2,000lbsof fuel being consumed from each outboardmain tank prior to display of the EICASadvisory message FUEL OVRD CTR L, R.This condition is normal, and is not indicatedby green fuel flow lines on the secondaryEICAS fuel display.

The FSMCs will activate override/jettisonpumps 2 and 3 when the FUEL OVRD CTRmessage is displayed. The override/jettisonpumps 2 will supply fuel to engines 1 and 2,while override/jettison pumps 3 will fuelengines 3 and 4.

If the crew turns off the center wing tankoverride/jettison pumps, or experiences afuel pump failure prior to having used all thefuel contained in the center wing tank, thescavenge pump will begin transferring fuelautomatically from the center tank at thesame time the FSMCs begin transferringfuel from the reserve wing tanks. This willoccur when main tank 2 or 3 fuel quantitydecreases to 40,000lbs. Fuel transfers fromeach reserve tank into its respective maintank 2 or main tank 3 respectively.

When main tank fuel quantity for all fourmain tanks is equal, the EICAS advisorymessage FUEL TANK/ENG is displayed. Atthis time, the crew should verify fuel tank

quantities, close crossfeed valve switches 1and 4, and push off the override / jettisonpump switches. Main tank fuel pumps willprovide fuel for their respective engines untilshutdown.

Operating With Center Wing Tank Empty:When the center wing fuel tank is empty,fuel operations are slightly less complex. Ifmain tank 2 and 3 fuel quantity exceedsmain tank 1 and 4 quantity, open allcrossfeed valves and turn on all main tankfuel boost and override/jettison pumps. Inthis configuration, the FSMCs will draw fuelfrom main tanks 2 and 3 until main tank fuelquantity is equal, at which time the fuelsystem should be reconfigured as describedabove for tank-to-engine fuel feed.

If main tank fuel quantities are equal beforeengine start, open only crossfeed valves 2and 3 and turn on only the main tank boostpumps. In this configuration main tank fuelpumps will provide fuel for their respectiveengines until shutdown.

Fuel Quantity Indicating System (FQIS):The FQIS measures the total fuel weight ofthe aircraft, as well as the fuel weight ofeach individual tank. This information isdisplayed both in the cockpit and on thefueling station panels.

The indicating system is comprised of tankunits and compensators which measure fuelvolume, as well as densitometers whichmeasure fuel density. The fuel weight isthen continuously updated to the secondaryEICAS and the fueling station panel.

Fuel temperature is only measured frommain tank number 1. This information isdisplayed directly on the primary EICAS.

Fuel Jettison System: The fuel jettisonsystem is designed to allow the crew toautomatically jettison fuel to a pre-determined level. This level can be selectedby rotating the “Fuel To Remain” knob onthe fuel jettison panel.

Selecting either A or B jettison system willdisplay the fuel to remain information on theprimary EICAS.



The fuel management system will calculatefuel jettison time and display it on thesecondary EICAS fuel page.

When the fuel jettison system is selected,pushing either of the FUEL JETTISONNOZZLE switches ON activates all of theoverride/jettison pumps in tanks currentlycontaining fuel. The four fuel jettison valveswill also be opened, and the number 1 andnumber 4 main transfer valves armed. Thejettison nozzles will open at this time.

Pushing the second FUEL JETTISONNOZZLE switch to ON will open the fueljettison valves.

Fuel jettison will end automatically when thetotal fuel quantity is reduced to the fuel toremain quantity selected by the crew. Thefuel to remain quantity indication changescolor to white and flashes for 5 seconds, andall override/jettison pumps will bedeactivated. The fuel system should bemanually reconfigured for FSMCs operationat the conclusion of any fuel jettison in orderto prevent fuel imbalance or inadvertent fuelstarvation of an engine.

Fuel Transfer: Fuel can be gravitytransferred from main tank 1 to main tank 2and main tank 4 to main tank 3 respectively.This is accomplished by pressing the FUELXFER MAIN 1 & 4 switch to ON.

Secondary EICAS Fuel System Synoptic:The fuel synoptic display can be called upon the secondary EICAS display by pressingthe FUEL switch on the EICAS controlpanel. The display shows the currentoperating status of each individual fuelpump, as well as the fuel quantities of eachtank, and the aircraft as a whole. Indicatorswill also be displayed to show fuel transfereither by gravity or scavenge pumps, as wellas normal, under pressure fuel flow (greenbanding).



FUEL SYSTEM AND EICAS FUEL SYSTEM DEPICTION

Reserve Tank 3Main Tank 4Main Tank 3

Center Wing TankStabilizer Tank

Main Tank 2Main Tank 1Reserve Tank 2



FUEL SYSTEM CONTROL PANEL DIAGRAM

Fuel Crossfeed Valves: Allows transferbetween systems when open. Separatestank pumping systems when closed.

CTR Wing Tank Boost Pump Switches:Left and Right Pumps.

MAIN Tank 2 Boost Pump Switches:FWD and AFT pumps.

MAIN Tank 2 OVRD Pump Switches: FWDand AFT pumps.

MAIN Tank 1 Boost Pump Switches: FWDand AFT pumps.

STAB Tank Boost Pump Switches: Leftand Right Pumps.

MAIN Tank 3 Boost Pump Switches:FWD and AFT pumps.

MAIN Tank 3 OVRD Pump Switches:FWD and AFT switches.

MAIN Tank 4 Boost Pump Switches: FWDand AFT Pumps.



FUEL CONTROL PANEL / FUEL PUMP SCHEMATIC



FUEL SYSTEM EICAS MESSAGES:>XFEED CONFIG One or more fuel crossfeed valves incorrectly configured.

>ENG 1,2,3,4 FUEL VLV Engine fuel valve or fuel spar valve position disagrees withcommanded position.

FUEL AUTO MGMT Both fuel management cards have failed and stabilizer fuel hasbeen transferred.

FUEL X FEED 1,2,3,4 Crossfeed valve is not in commanded position.

FUEL IMBALANCE Fuel difference of 6,000lbs between inboard main tanks (2 and3) and outboard main tanks (1 and 4) after reaching FUEL TANK/ ENG condition.

FUEL IMBAL 1-4 Fuel difference of 3,000 pounds between main tanks 1 and 4.

FUEL IMBAL 2-3 Fuel difference of 6,000 pounds between inboard tanks 2 and 3.

>FUEL JETT A B Selected jettison system has failed.

FUEL JETT SYS Fuel total less than fuel to remain and one nozzle valve open orboth jettison cards failed.

FUEL PRESSURE ENG Engine is on suction feed

FUEL PUMP 1,2,3,4 FWD Respective fuel pump is inoperative.FUEL PUMP 1,2,3,4 AFTFUEL OVRD 2,3 FWDFUEL OVRD 2,3 AFTFUEL OVRD CTR L, RFUEL PUMP STAB L, R

FUEL QTY LOW Fuel quantity is 2,000lbs or less in one or more main tanks.

FUEL RES XFR 2,3 Reserve transfer vales not in commanded position.

FUEL STAB XFR Horizontal stabilizer fuel fails to transfer.

>FUEL TANK/ENG Main tank 2 quantity is equal to or less than main tank 1 quantity,or main tank 3 quantity is equal to or less than main tank 4quantity and crossfeed valve 1 or 4 is open.

>FUEL TEMP LOW Fuel temperature is -37C or less

>FUEL TEMP SYS The fuel temperature system is inoperative.

>JETT NOZZLE L (R) Nozzle valve position disagrees with commanded position.

>JETT NOZZLE ON Fuel jettison nozzle valve is open.>JETT NOZZ ON L, R Fuel jettison nozzle valve is open.



HYDRAULIC SYSTEMOverview: The 747-400 has fourindependent hydraulic systems installed,one per engine. The systems are numbered1 through 4 in accordance with the enginenumbering.

Each hydraulic system is comprised of ahydraulic reservoir, and engine drivendemand pump and an air driven demandpump. The engine driven demand pumpsare located within the engine nacelle of eachengine, and are driven by the accessorydrive. The reservoir for each system islocated in the engine pylon, above andbehind the engine.

Engine number 4 has an electrically drivenAUX hydraulic system, which can only beactivated while the aircraft is on the ground,and is used primarily to power the brakesduring towing operations.

Hydraulic power is used to operate thefollowing systems:

• Autopilot Servos• Brakes• Flight Controls• Landing Gear• Nose and Body Gear Steering• Spoilers• Stabilizer Trim• Thrust Reversers• Trailing Edge Flaps

Hydraulic Reservoirs: Each hydraulicsystem has an independent reservoir whichis located in the engine pylon. The reservoiris pressurized using regulated air from thepneumatic system.

Hydraulic reservoir quantity is measured anddisplayed on the secondary EICAS display.In the event the hydraulic reservoir needs tobe replenished, all four systems can beserviced from a single location in the leftbody gear bay.

Hydraulic fluid is cooled by hydraulic fluidheat exchangers installed in the main fueltanks. This process provides fuel heatingand hydraulic system cooling.

A SYS FAULT light on any of the fourhydraulic systems can indicate either lowhydraulic pressure, low reservoir quantity orhigh hydraulic fluid temperature.

Engine Driven Pumps: The engine drivenpumps are located in the accessory sectionof each engine nacelle and connected to theaccessory drive. The pumps providepressure to the hydraulic system when theengine is rotating and the ENGINE PUMPswitch is in the ON position. If the enginepump switch is selected OFF, or if theengine fire shutoff handle is pulled, enginedriven pump will not operate.

Auxiliary Demand Pumps: There are fourauxiliary hydraulic demand pumps on the747-400. Auxiliary Demand Pump (ADP) 1and 4 are powered by pneumatic bleed air,while ADP 2 and 3 are driven by AC electricpower.

The auxiliary demand pumps can beoperated in AUTO or ON (continual). Thepumps are normally placed in AUTO whichwill cause the demand pump for eachsystem to operate whenever low systempressure output is detected from the enginedemand pump. The system will also providepressure if the FUEL CONTROL switch forthe engine is placed in the shutoff position.

Hydraulic systems 1 and 4 will activate toprovide supplemental pressure when theflaps are in transit, and whenever flaps areselected out of UP during flight. Thisbehavior requires that the Auxiliary Pumpselector switch be in the AUTO position.

If an Auxiliary demand pump is activated asa result of low output pressure from anEngine Driven Pump, it will continue tooperate for 14 seconds after sensing that itis no longer needed because of correctoutput pressure from the Engine DrivenPump.

This delay is designed to prevent rapidpressure fluctuations.



The status of the ADPs is shown on thesecondary EICAS hydraulic display. ADPpumps can appear in the following status:

Blue: Pump in standby modeprogrammatically.

Amber: A fault is detected or the pump hasfailed to activate when required.

White: Normal operating condition.

Electric AUX System: Hydraulic system 4has an electrically driven auxiliary pumpinstalled just aft of the reservoir in thenumber 4 engine pylon, adjacent to thedemand pump. This electric AUX systemwill provide system pressure to the number4 hydraulic system for brake operationduring ground towing. The system willautomatically cease providing pressure oncethe engine driven pump begins providingoutput that is within system parameters. Ifthe selector switch is left in the AUXposition, an EICAS advisory message willremind the crew to rotate the selector toAUTO.

Hydraulic System 1: The number 1hydraulic system provides hydraulic powerto:

• Center Autopilot Servos• Engine 1 Thrust Reverser• Flight Controls• Alternate Brakes• Trailing Edge Flaps• Nose and body gear actuation and

steering.


• Right Autopilot Servos• Engine 2 Thrust Reverser• Flight Controls• Alternate Brakes• Stabilizer Trim


• Left Autopilot Servos• Engine 3 Thrust Reverser• Flight Controls• Stabilizer Trim


• Engine 4 Thrust Reverser• Flight Controls• Normal Brakes• Trailing Edge Flaps• Wing Gear Actuation

Hydraulic System 4 AUX: The number 4AUX hydraulic system provides hydraulicpower to:

• Normal Brakes

EICAS STAT Screen Hydraulic Indicators:When the STAT switch is pressed on theEICAS control panel, the flight control statusdisplay will be brought up on the secondaryEICAS display. The top portion of thisscreen display is dedicated to providing abasic overview of the hydraulic systemstatus, as displayed below.

Hydraulic Quantity Warning: The STATdisplay provides a LO quantity indicatorwhen hydraulic quantity has dropped todangerously low levels in the hydraulicreservoir. Warnings displayed in amber.



SECONDARY EICAS DISPLAY - HYDRAULIC SYSTEM SYNOPTIC

Secondary EICAS HYD Display: TheEICAS HYD display provides valuableinformation regarding the current state of thehydraulic systems. Graphic and numericdisplays of hydraulic quantity, numerictemperature and pressure display, as wellas hydraulic pump status indicators and flowschematics make trouble shooting andidentifying hydraulic system problemssignificantly easier.

Engine Driven Pump: Box will display OFFif pump fails or is selected OFF.

AUX Demand Pump: Circle will displayOFF if pump fails or is selected OFF.

Hydraulic Power Flow Bar: Green flow barindicates current hydraulic power flow.

Hydraulic System Numeric Data:General health of the hydraulic system isdisplayed here. Out of limits data isdisplayed in amber or red

HYD Display Examples: The HYD displaybelow shows four HYD system scenarios.

SYSTEM 1: Engine Driven Pump ON. AuxPressure Demand Pump ON. (Systemproducing normal HYD power.)

SYSTEM 2: Engine Driven Pump OFF. AuxDemand Pump ON. (System producingnormal HYD power.)

SYSTEM 3: Engine Driven Pump OFF. AuxDemand Pump ON. Shutoff Valve CLOSED.(EDP not producing HYD power due to FIRESHUTOFF handle being activated.)

SYSTEM 4: Engine Demand Pump ON. AirPressure Demand Pump AUTO. (Systemconfigured for normal operation andproducing normal HYD power.)

Shut Off Valve: If FIRE SHUTOFF handleis pulled, shutoff valve will display aCLOSED position.

Hydraulic Reservoir Quantity Indicator:Displays a graphical interpretation of thelevel of hydraulic fluid contained within thesystem. Displayed as a percentage of theFULL capacity. As quantity drops, levelindicator drops. (Compare SYS 3 and SYS4.)



HYDRAULIC SYSTEM CONTROL PANEL

SYS FAULT Light: Indicates low outputpressure, low reservoir quantity or high fluidtemperature.

DEM PUMP PRESS Light: Indicates theDEMAND PUMP selector is OFF, the pumpis operating, and output pressure is low.May also indicate that pump has failed tooperate.

Demand Pump Selector: Allows crewselection of the appropriate demand pumpmode.

OFF: Shuts off appropriate pump.

AUTO: Causes demand pump to operate ifthe engine driven pump pressure falls belownormal levels, or when the FUEL CONTROLselector switch is set to CUTOFF, or whenthe hydraulic shutoff valve has beencommanded closed by the FIRE SHUTOFFvalve.

ON: Pump operates continually.

ENG PUMP Switch: When selected ON,allows the engine driven hydraulic pump toprovide pressure to the hydraulic system.

ENG PUMP PRESS light: Indicates lowengine driven pump output pressure whenilluminated.



HYDRAULIC SYSTEM EICAS MESSAGES:HYD OVHT SYS 1,2,3,4 Excessive hydraulic system temperature.

HYD PRESS DEM 1,2,3,4 Demand pump output pressure is low.

HYD PRESS ENGE 1,2,3,4 Engine pump output pressure is low.

HYD CONTROL 1,4 Auto control of hydraulic system demand pumps is inoperative.

HYD PRESS SYS 1,2,3,4 Loss of system pressure.

>HYD QTY HALF 1,2,3,4 Hydraulic quantity is ½ normal service level.

>HYD QTY LOW 1,2,3,4 Hydraulic quantity is 0.34 normal service level.



ICE AND RAIN PROTECTIONOverview: The 747-400 has acomprehensive package of anti-icing forsensors, probes, engines and flight controlsurfaces. The operation of these anti-icesystems is largely automatic and requires nointeraction from the crew.

Anti-ice systems for engines and wingsrequire only modest attention from the crew.

Probe Heat: Operation of the probe heatsystem is fully automatic. Four pitot-staticprobes and two angle of attack probes areelectrically heated for anti-ice protectionwhenever any engine is operating. Twototal air temperature probes are electricallyheated for anti-ice protection only in flight.

The primary EICAS will display an advisorymessage to indicate that a probe heater hasfailed or power to the heater is not present.An EICAS advisory message will also bedisplayed if ground/air logic has failed toremove power and a TAT probe is heatedon the ground.

Nacelle Anti-Ice: The engines receiveanti-ice protection through the nacelle anti-ice system. Nacelle anti-ice may beoperated in flight and on the ground asrequired.

When NAI is selected ON, bleed airpressure opens the nacelle anti-ice valve

allowing bleed air to flow to the respectiveengine inlet cowl. However, bleed air is notavailable for nacelle anti-ice operation whenthe pressure regulating valve has beenclosed due to:

• Bleed air overheat• The High Pressure bleed valve

failed to open.• The start valve is not closed.

When NAI is selected ON with the enginebleed valve closed, the High Pressure bleedvalve remains closed, but the NAI receivesrequired bleed air from the system.

An advisory message and the VALVE lightlocated in the NAI switch will illuminate inthe event that the NAI valve and switchposition disagree. Display of the EICASmessage is delayed for three seconds toallow for valve transit time.

NAI should be operated in conditions wherevisible moisture is present and thetemperature is 10°C of less. If NAI isselected ON when the temperature isgreater than 12°C or greater, and EICASadvisory message will remind the crew todeselect NAI.

Wing Anti-Ice: Pushing the Wing Anti-Ice(WAI) switch ON opens a valve in each wingthat allows bleed air to flow from the enginesto a series of spray tube ducts in the leadingedge of the wing. WAI is ineffective whenthe leading edge flaps are extended, andcannot be activated while the aircraft is onthe ground.

EICAS displays an advisory message andthe WAI valve light illuminates in the eventthat a valve disagrees with the commandedposition of the switch. The EICAS messageis delayed three seconds in order to preventtransient messages while the valves are intransit.

WAI should be operated in conditions wherevisible moisture is present and thetemperature is 10°C of less. If WAI isselected ON when the temperature isgreater than 12°C or greater, and EICAS



advisory message will remind the crew todeselect WAI.Primary EICAS display: Each of four NAIvalves (one per engine) are displayed on theprimary EICAS as a status advisory to thecrew when NAI is in operation.

Both WAI valves are displayed as advisorieswhen WAI is in operation as well.

Secondary EICAS display: The secondarysynoptic ECS display also provides the crewwith an indication of NAI and WAI activity.

NAI and WAI operation is identified by theNAI and WAI chutes shown on therespective engine and wing valve identifiersshown in green.

The airflow displayed is generated by thedisplayed valves positions, switch positionsand pack status. The display does not showactual air flow and therefore the display maynot represent the actual system operation.

EICAS MESSAGES:>ANTI ICE Any anti-ice system is on and TAT is greater than 12C.

HEAT P/S CAPT F/O Heater failure on associated probe.HEAT P/S L, R AUXHEAT L, R TATHEAT L, R AOA

NAI VALVE 1,2,3,4 Nacelle anti-ice valve is not in commanded position.

WAI VALVE LEFT, RIGHT Wing anti-ice valve is not in commanded position.

.



LANDING GEAROverview: The nose gear on the 747-400 isa standard, two-wheel, non-braked stearablenose gear design. The main landing gearare comprised of four main gear trucks,each with four wheels. The two wingmounted gear are referred to as the WingGear, and the fuselage mounted gear arereferred to as the Body Gear.

Hydraulic power for the landing gear isprovided by systems 1 and 4. System oneprovides power to the nose and body gear,while system four provides power to thewing gear. In the event of hydraulic failure,an alternate gear extension system isavailable which electrically releases the up-locks and allows aerodynamic loading andlanding gear weight to lower the gear to thelocked position.

Braking is provided by both a normal and analternate system, each equipped withantiskid systems. Autobraking capability isprovided for the normal brake system only.

Landing Gear: Then main landing gear onthe 747-400 is an extremely complexarrangement of wing and body gear withvery tight clearance tolerances during theretraction process. As such, each of thewing and body gear assemblies is equippedwith sensors to determine if the gear is inthe proper position prior to allowingactuation of the landing gear lever.

These sensors require that the wing gear bein a tilted position and the body gear in acentered position before the gear up handlewill unlock. Under normal conditions, thiswill occur within three seconds of aircraftliftoff.

In addition to unlocking the landing gearlever, a number of other aircraft functionsare directly linked to the main and body geartilt sensors, as well as a nose gear liftoffsensor which detects weight on the nosegear assembly. Unless all of these sensorsare correctly positioned, the crew may notbe able to retract the landing gear, or utilizeother air/ground specific systems.

The landing gear doors are powered by thehydraulic system which powers the landinggear sub-system. Hydraulic power isrequired for landing gear door closure.

During the gear retraction sequence, theautobrake system will apply brake pressureto eliminate will movement before thelanding gear are in the up and lockedposition. The nose gear uses a snubbingprocess to eliminate wheel movement duringthe retraction process.

Landing Gear Position Indicators: Thelanding gear position indicator is displayedon the primary EICAS when the landing gearare extended

The landing gear position indicator isremoved from the EICAS display when thelanding gear are in the up and lockedposition.

Expanded Gear Disagree Indicator: If anyabnormal condition exists with the landinggear the EICAS will provide an expandedgear position display to show the dispositionof all five gear assemblies. This expandeddisplay will also appear if the ALTN GEARextension switch is pushed, or if a GEARDISAGREE warning message is present

DN indicates gear system down and locked.Crosshatches indicate gear not down andlocked.

If any gear position sensor fails, it will bereplaced on the expanded EICAS gearindicator with an amber X.

Landing Gear Brake System: The normalbrake system is powered by the number 4



hydraulic system, with a brake pressureaccumulator.

The 747-400 is equipped with carbonbrakes. The braking capabilities provided bycarbon brakes are such that automatic braketorque limiting systems are installed toprevent excessive stress from being placedon the landing gear by over braking. Ifexcessive brake torque is sensed by theantiskid system, the wheel transducer willtrigger an antiskid signal to alleviate brakepressure on that wheel.

Each wheel is equipped with a braketemperature monitoring system, whichprovides direct temperature indication tosecondary EICAS GEAR display. Thisdisplay allows the crew to monitor thetemperature of each individual brake subsystem.

Antiskid: The anti skid system is entirelyautomated, and does not include any cockpitcontrols. The system receives input fromtransducers in each main wheel, and uses areference velocity provided by the IRSground speed signal to prevent wheellocking, skidding and hydroplaning.

Autobrakes: The autobrake system alsoreceives power from hydraulic system 4.The system is designed to operate inconjunction with the automated flightsystems to provide predictable decelerationrates during a rejected takeoff, or duringlanding. The rate of deceleration can beselected by a cockpit control capable ofbeing set to RTO, 1, 2, 3, 4 or MAX AUTO.Setting 1 will provide a deceleration rate of 4ft/sec2, while MAX AUTO will provide adeceleration rate of up 11 ft/ sec2.

The RTO setting will provide maximumbraking pressure automatically if thethrottles are moved to idle after the aircrafthas accelerated beyond 85 knots.

The autobrake system will automaticallydisarm itself after aircraft liftoff. The systemwill also disarm in the following situations:

• Advancing any throttle beyond idleforward after touchdown.

• Antiskid System Malfunction.

• Application of brake pressure by thecrew,

• Autobrake System Malfunction.• Moving the autobrake selector switch to

DISARM or OFF.• Moving the speedbrake selector handle

to DN after landing.• Normal Brake System Malfunction.

In the event that the normal braking systemprovided by hydraulic system 4 isinoperative, an alternate braking system isprovided by system 1, or system 2 (shouldsystem 1 fail as well.) Brake pressure isselected automatically, and will switchimmediately if the system in use beginsproviding low output pressure.

The alternate braking systems are providedthrough separate brake lines and throughseparate metering systems. The alternatebrake system has all the normal brakecapabilities of antiskid, but does not provideautobrake capability. This will beannounced on the primary EICAS if thealternate brake system is being used.

Ground Steering: In order to allow foradequate rudder usage during the highspeed portion of the takeoff and landingphase of flight, nose gear steering is limitedto 7º of deflection from the rudder pedalthrow. For proper ground steering, eachcrew member is provided with a steeringtiller which allows the nose wheel steeringassembly to be rotated to 70 degrees ineither direction. This tiller should be usedfor taxi operations.

Any time the aircraft ground speed is lowerthan 15 knots and the steering tiller is usedto deflect the nose wheels beyond 20ºdeflection, the body gear steering isautomatically actuated, turning the bodygear in the direction opposite the nose gear.This action dramatically reduces the turningradius of the 747-400, as well as reducingthe amount of scrubbing received by thebody gear tires. If aircraft speed increasesbeyond 20 knots while body steering isenabled, the system will automaticallycommand the body gear to center theirsteering mechanisms. An EICAS warningwill sound if the body gear are not properlypositioned for takeoff. Taking off with the



body gear steering out of synchronizationwill prevent gear retraction.

Body gear steering is provided by hydraulicsystem 1. There is no backup system forthis function.

Landing Gear Configuration Warning: Ifthe aircraft detects the landing gear are notproperly configured when the flaps arecommanded to flaps 25 or 30, and theaircraft is below 800 feet AGL, a landinggear configuration warning will sound.

This warning will also sound in any casewhere the landing gear system detects agear assembly is not locked down, or isimproperly positioned. Pushing theGEAR/CONFIG OVRD switch will lock outthis automated warning system.

CONFIG GEAR OVRD:

Secondary EICAS Display - Landing GearSynoptic: When the EICAS control panelGEAR switch is pressed, the secondaryEICAS displays a GEAR overview whichdepicts the current tire pressure, braketemperature, and door assemblyconfiguration for each landing gear subassembly. This display can be used todiagnose landing gear problems, as well asto monitor brake temperatures and tirepressures after abnormal takeoff/landingsituations.

Tire Pressure Indication:

Brake Temperature Indication: Normalrange is 0-4 and is displayed in white.Caution range is 5-9 and is displayed inamber.

Gear Door Configuration: Cross hatchesindicate door in transit or landing gear out ofsynch.



LIGHTING SYSTEMS

Overview: The aircraft lighting systemprovides for flight deck, passenger cabin,cargo and service compartment lighting aswell as exterior and emergency lighting.

Storm Lights: The storm light switch is anoverride switch that sets all interior cockpitlights to a high brightness setting in order tocombat night blindness resulting fromlightning in close proximity to the airplane.This switch function is not modeled in thePMDG 747-400.

Circuit Breaker/Overhead Panel Dimmer:This dimmer knob controls the night lightingbrightness on the overhead panel and circuitbreaker panel above and behind theoverhead panel. Rotate the knob left/right toactuate its function at night.

Glare shield/Panel Flood Dimmer: Thisdimmer knob controls the night lightingbrightness on the main panel andglareshield. Rotate the knob left/right toactuate its function at night.

Dome Light: This dimmer knob is used toset the brightness of cockpit overheadlighting.

Aisle Stand Panel Flood Dimmer: Thisdimmer knob controls the night lightingbrightness on the center console/aisle stand.Rotate the knob left/right to actuate itsfunction at night.

Landing Lights: Two fixed landing lightsare installed in the leading edge of eachwing. Each light is controlled by the L or ROUTBD or L or R INDB switch. When alanding light switch is in the ON position, the

wing landing light is at maximum brightnessif the landing gear are selected DOWN. Thelight is dimmed automatically when thelanding gear are not in the down position.(This dimming functionality is not modeled inthe PMDG 747-400)

Runway Turnoff Lights: The two runwayturnoff lights are mounted on the nose gearstructure and are aimed approximately 65degrees to the left and right of the airplanecenterline.

Runway Turnoff Lights: The L and R RWYTURNOFF switches on the overhead panelcontrol the lights. The air/ground sensingsystem determines he conditions when thelights illuminate or extinguish based oninterface with the air/ground sensor. Theturnoff lights will only operate while theaircraft is on the ground.

Taxi Lights: The TAXI light switch on theoverhead panel controls the taxi light. Thetaxi lights are located on the nose landinggear. The air/ground sensing systemdetermines the conditions when the lightsilluminate or extinguish provided that thelight switch is in the ON position. With theswitch ON, the taxi lights illuminate when theair/ground sensing system is in the groundmode.

Beacon Lights: The BEACON light switchon the overhead panel controls the red anti-collision lights. On the aircraft there are twobeacon strobes, Lower and Upper that canbe operated individually. This functionality isnot modeled in the PMDG 747-400, andinstead the beacons have an ON and OFFcondition.

Navigation Lights: The navigation lightsswitch controls the aircraft position lights.The position lights are two fixed position



green lights on the right wingtip, and twofixed position red lights on the left wingtip,and two fixed white lights on the tail conenear the APU exhaust outlet.

Strobe Lights: The strobe lights switch onthe overhead panel controls the three whitestrobe lights. One strobe light is installed oneach wing tip and one on the tail cone.

Wing Lights: The wing lights switch on theoverhead panel activates wing leading edgeillumination lights. The lights illuminate thewing leading edge and engine nacelles. Thelights are flush-mounted on the fuselage.

Logo Lights: The logo lights are installedon the horizontal stabilizers to illuminate thevertical stabilizer markings to improvevisibility of the airplane.

Indicator Lights Test: This switch is usedto test the function of light bulbs throughoutthe cockpit. This functionality is not modeledin the PMDG 747-400.

Screen Dimming: The PMDG 747-400 hasthe ability to dim the individual screenswithin the cockpit. The knobs for thisfunctionality are included in the VirtualCockpit, and are not available in the 2Dcockpit. The dimmer knobs are located tothe left/right of each pilot on the edge of theglare shield.

Emergency Lights: The passengeremergency exit lights are controlled usingthe switch on the overhead fire controlpanel. These lights should be ARMED anytime the aircraft is in operation. They should

be turned to ON to aid an evacuation, andturned OFF when the airplane is shut down.

An EICAS message will alert the crew if thestatus of the emergency exit lights does notmatch the operation of the aircraft.



PNEUMATIC SYSTEMS

Overview: The engines, APU or anexternal air bottle can provide pressure airfor the pneumatic system. The pneumaticsystem on the 7474-400 distributes highpressure air to the following systems:

• Air Pressure Driven Hydraulic DemandPumps.

• Aft Cargo Heat.• Cabin Air Conditioning.• Cabin Air Pressurization.• Cargo Smoke Detection System• Engine Start.• Hydraulic Reservoir Pressurization

System.• Nacelle Anti Ice (In conjunction with

Engine Bleed Air).• Potable Water System Pressurization.• Wing Anti Ice.• Leading Edge Devices.

External Air: External air can be suppliedto the pneumatic system via two separateconnectors while the aircraft is on theground. The connectors are located on thebottom of the fuselage, just aft of the airconditioning packs, and are usually onlyused to provide engine starting pneumaticpressure in the event APU pneumaticpressure is unavailable. The use ofpneumatic air is depicted by a green EXTAIR on the secondary EICAS ECS display.

APU Bleed Air: The APU supplies airthrough a bleed air valve to the pneumaticsystem. If started while on the ground, theAPU can provide pneumatic support to thesingle operating air conditioning pack, whichwill allow full engine power to be dedicatedto takeoff thrust. The APU can be used forair conditioning purposes up to 15,000 feet,

by which time pneumatic support of the airconditioning packs should have beentransferred to the engines.

Engine Bleed Air: Each engine is capableof providing temperature limited bleed airthrough a pressure regulating valve (PRV).The PRV will automatically meter theamount of bleed air based on systemdemand and engine thrust setting.

During high thrust conditions, such astakeoff or cruise, the PRV will modulateengine bleed air through the Intermediatepressure bleed valve. During low thrustflight conditions, the PRV will modulate tosupply bleed pressure from the highpressure bleed stage, based on systemdemand.

Engine bleed air temperature is regulated byan engine mounted pre-cooler. The pre-cooler functions as a heat exchanger, usingfan air to cool engine bleed air. The systemregulates the temperature of engine bleedair by modulating the amount of fan airallowed to enter the heat exchanger.

Engine Bleed Air Valve: The engine bleedair valve regulates the engine bleed air toprovide normal bleed air system pressure. Italso prevents reverse flow of bleed air fromthe duct, except during engine starting. Ifthe air pressure in the bleed duct fromanother source is higher than the bleed airfrom an engine, the engine bleed valve willclose. The engine bleed air valve will openautomatically when engine bleed airpressure is sufficient to produce forward airflow.

Engine Bleed Switch: Pushing an enginebleed air switch ON allows the system logicand bleed air pressure to open the HP bleedvalve, the Pressure Regulating Valve andthen allows bleed air pressure to open therespective engine bleed air valve tointroduce air flow into the bleed air duct.The respective engine bleed air switch OFFlight is illuminated when an engine bleed airvalve is not open.



Nacelle Anti-Ice: Bleed air for NAIoperation is available to the engine even ifthe bleed switch is selected off. Thefollowing conditions will prevent bleed airfrom being available for the engine NAIoperation:

• The PRV has failed closed.• The PRV has been closed due to a

bleed air overheat.• The start valve is not closed.• The HP bleed valve failed open.

Distribution: The pneumatic system iscapable of accepting bleed air from anyengine, and distributing it to any unitrequiring bleed air. To isolate a pneumaticleak, a bleed duct leak or overheatcondition, either of the isolation valves canbe selected closed. This will protect theintegrity of the rest of the bleed air system.

Pneumatic System Indications:Pneumatic duct pressure in the left and rightpneumatic ducts is continually displayed onthe primary EICAS. The secondary EICASECS display provides a detailed overview ofthe pneumatic system status based uponswitch positions and sensors. The status ofeach bleed valve and isolation valve can beseen, as well as NAI, WAI functions andcurrent pneumatic system pressure on bothsides of the pneumatic system. .



SECONDARY EICAS DISPLAY - PNEUMATIC SYSTEM SYNOPTIC

Secondary EICAS Pneumatic Indications:The secondary EICAS pneumatic display iscontained on the Environmental ControlSystems (ECS) screen. This screencontains environmental control indications,cabin pressurization indications, as well as aschematic of the pneumatic bleed airsystem.

Pneumatic System Isolation Valves:

Pneumatic System Duct PressureIndicator:

Pneumatic Air Pressure Flow (green):

APU Bleed Valve (shown closed):

Engine Bleed Valves (shown open):

Pneumatic System Control Panel: Thepneumatic system is controlled using thepneumatic system control panel, which islocated on the overhead panel. This panelis comprised of controls for both thepneumatic and pack control systems.

Isolation Valve Switch: Open or closeassociated ISLN valve. VALVE lightilluminated indicates associated valvedisagrees with switch position.

SYS FAULT Lights: Indicate bleed airoverheat or overpressure, pressureregulating valve or high pressure bleedvalve open when switch position requirethem to be closed.

APU Bleed Air Switch: [ON] Valve openswhen switch is placed on and APU N1% isgreater than 95%. VALVE light illuminatedindicates valve position disagrees withcommanded switch position.

Engine Bleed Air Switches: [ON] Enginebleed air valve, pressure regulating valve,and high pressure bleed valve open. [OFF]Engine bleed air valve, pressure regulatingvalve and high pressure bleed valve closed.



GLOBAL NAVIGATION SYSTEMS

Overview: The PMDG 747-400 simulates amodernized 747-400 equipped with GPS asa primary navigation source for the FlightManagement System. The airplane is alsoequipped with an inertial navigation systemthat provides heading, attitude, altitude,speed and acceleration data to the FMS.

Inertial Reference Units: The IRU’s arelocated on the upper left column of theoverhead panel. Three knobs are used tointerface with the IRUs and allow the crewthe determine the operating mode for eachunit individually as needed.

If loading the airplane in a scenario wherethe aircraft is already operating it will not benecessary to align the IRU’s. If you arestarting with a “Cold and Dark” scenario, it

will be necessary to bring the IRU’s onlinerealistically in order to have navigation andattitude/airspeed functionality.

To align the IRU’s, rotate each knob fromOFF to NAV (they are spring loaded to theNAV position when rotating from OFF).Selecting NAV will begin the alignmentprocess. Alignment requires approximatelyten minutes unless you have selected adifferent figure from the PMDG/OPTIONSmenu.

Present position must be entered into thePOS INIT page of the FMC/CDU in order tocomplete the alignment process. Alignmentcan only be accomplished while the airplaneis stationary. Do not allow the airplane to bemoved during alignment. The InertialReference System is aligned when all threeIRUs have entered the navigation mode atthe conclusion of their alignment period.

Latitude and Longitude entries will thenblank on the SET IRS POS line of the POSINIT page in the CDU.



CENTER PEDESTAL SYSTEMSOverview: The center pedestal houses awide array of functions from communicationand ATC to autobrakes and passengerwarning signs.

Communications Radios: Thecommunications radios are modeled toincorporate nearly all MSFS functionality.Based on the lack of integrated audiocircuitry within MSFS, we have not modeledthe ability to monitor audio input onsecondary channels.

To use the communications radios, selectthe desired frequency in the STANDBYwindow, then use the frequency flip-flop keyto move the frequency to the ACTIVEwindow.

Navigation Radio Signal Monitoring: Theradio frequency identifier information isprimarily monitored by automatic systemsaboard the airplane. When a signal hasbeen positively identified, it’s identifyinginformation accompanies it’s display on theNavigation Display.

Autobrakes: The Autobrakes selector isfound on the center pedestal. Select theswitch to RTO for Rejected Takeoffactivation of the braking system.

Select landing settings of 1 –MAX, based onyour desire level of braking upon landing.For a full description of autobrakefunctionality please see chapter 3.

Flight Control Trimming: Flight controltrim controls are found on the centerconsole.

Transponder and TCAS Controls:Transponder and TCAS controls areencapsulated in a single TransponderControl Unit.

Transponder biasing for ABOVE andBELOW traffic, relative altitude (Absolute orRelative) as well as ATC IDENT controls arefound here.

The transponder control knob must be set toeither TA or TA/RA (Traffic Advisory orTraffic Advisory/Resolution Advisory) inorder to display TCAS information on theNavigation Display.

11 Aircraft Systems 747 400 v10

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Transcript of 11 Aircraft Systems 747 400 v10