POWER PLANT - ADJUSTMENT/TESTtecpubhc.com/jml/images/P_WC/PT6T-3D/MAINT/71/POWER...nf power turbine...

71-00-00Engine Model(s): MODEL(S)PT6T-3D/PT6T-3DE/PT6T-3DF

POWER PLANT - ADJUSTMENT/TEST1. General

A. Use of Procedures

This section contains information for PT6T-3D/-3DE/-3DF engine ground running for checks andadjustment/test procedures to verify integrity of installed/replaced items and to facilitatetroubleshooting. These procedures are applicable solely to Pratt & Whitney Canada (P&WC)supplied items and do not cover any airframe supplied parts.

For up-to-date technical accuracy for ground running, trim adjustments etc., the procedurescontained in the Power Plant Section of the airframe manufacturer's Flight Manual takeprecedence and must be referred to.

Before making any control adjustment/check, engine should be run for ten minutes minimum,and all parameters stabilized.

B. Symbols

The P&WC symbols designated for the working variables used in the adjustment/test procedurescontained in this section, are defined as follows:

Pamb Ambient pressure

Pt2 Total pressure - compressor inlet

Tt2 Total temperature - compressor inlet

Tt5 Inter-turbine temperature

Wf Fuel flow

Ng Gas generator rpm

Nf Power turbine rpm

C. Ground Safety Precautions

WARNING: AT TAKEOFF POWER, THE EXHAUST STREAM MAY PICK UP AND THROWLOOSE DIRT, GRAVEL AND OTHER DEBRIS OVER A CONSIDERABLEDISTANCE. PRECAUTIONS MUST BE TAKEN DURING ENGINE RUNNING TOAVOID INJURY TO PERSONNEL AND DAMAGE TO PROPERTY.OCCASIONALLY, DURING POWER SECTION STARTING, EXCESS FUELACCUMULATES IN EXHAUST DUCT WHICH WHEN IGNITED CAUSES LONGFLAMES TO BE EMITTED FROM THE EXHAUST. PERSONNEL MUST ENSURETHAT THE RUN UP AREA IS CLEAR OF INFLAMMABLE MATERIALS ANDGROUND EQUIPMENT.

WARNING: CARBON MONOXIDE CONTENT OF EXHAUST GASES IS RELATIVELY LOW.HOWEVER OTHER GASES ARE PRESENT WHICH HAVE A DISAGREEABLEODOR AND AN IRRITATING EFFECT ON SKIN TISSUE. EXPOSUREUSUALLY RESULTS IN WATERING OF THE EYES ACCOMPANIED BY ABURNING SENSATION. LESS NOTICEABLE, BUT EQUALLY AS HAZARDOUSIS THE DANGER OF RESPIRATORY IRRITATION. FOR BOTH OF THESEREASONS, EXPOSURE TO EXHAUST GASES SHOULD BE AVOIDED,PARTICULARLY IN CONFINED SPACES.

WARNING: AFTER POWER SECTION OPERATION, SUFFICIENT TIME MUST BEALLOWED FOR COOL DOWN BEFORE INSPECTING OR WORKING IN THEEXHAUST CASE AREA.

MAINTENANCE MANUAL 71-00-00 - POWER PLANT - ADJUSTMENT/TESTManual Part No.3040592 Rev. 35.0 - 15/APR/19

Export Classification: ECCN=Contains 1025% 9E991;ECL=NSR Printed on 30/APR/19 P&WC Proprietary – subject to restrictions in Technical Data Agreement

WARNING: ALL JET FUELS AND LUBRICATING OILS HAVE AN INJURIOUS EFFECT ONTHE SKIN. PRECAUTIONS MUST BE TAKEN TO AVOID CONTACT AS MUCHAS POSSIBLE.

CAUTION: POWER SECTION COMPRESSOR INLET CASES ARE DESIGNED FORRELATIVELY LOW INTAKE AIR VELOCITY. NEVERTHELESS THEIMMEDIATE AREA OF THE INLETS MUST BE FREE FROM LOOSEOBJECTS, SAND, GRIT, RAGS AND SPILLED FLUIDS WHICH COULDPASS THROUGH THE INLET SCREENS AND CONTAMINATE OR DAMAGECOMPRESSOR BLADES.

(1) The preceding WARNINGS and CAUTIONS shall beobserved.

(2) The use of turbine-powered aircraft makes it necessary to improve existing ground safetyprecautions. To prevent injury to personnel and damage to property, handling and workingprocedures must be suitably modified depending on installations. When handling or workingon turbine-powered aircraft, not only must the areas with rotating components be avoided,but allowances must also be made for the hot, high velocity exhaust gases discharged fromthe exhaust nozzles (Ref. Fig. 501)



Figure 501 Exhaust Danger Area - Typical

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D. Environmental Conditions

(1) Ambient Conditions

CAUTION: WHEN STARTING AN ENGINE THAT HAS BEEN EXPOSED TO LOWAMBIENT TEMPERATURES, FUEL AND OIL PRESSURES MUST BECAREFULLY OBSERVED. LACK OF, OR BELOW NORMAL PRESSUREINDICATIONS ARE CAUSE FOR IMMEDIATE SHUTDOWN.

Engine performance is greatly affected by surrounding atmospheric conditions, so it isessential that accurate values of barometric pressure (not corrected to sea level) andambient temperature in the immediate area at the time of testing be obtained.Furthermore, it is highly desirable that power section trimming and performance checks becarried out with low wind velocity, and with the intake facing the wind.

(2) Cold Weather

CAUTION: FUEL DRAINING FROM AFFECTED COMPONENTS AFTER APPLYINGHEAT FOR SEVERAL MINUTES DOES NOT NECESSARILY MEAN THATALL ICE HAS MELTED. LUMPS MAY STILL REMAIN AS A SERIOUSHAZARD. HEATING MUST BE CONTINUED FOR A SHORT TIME AFTERFUEL BEGINS TO FLOW AND DRAINED FUEL INSPECTED UNTIL IT ISEVIDENT THAT ALL WATER HAS BEEN REMOVED.

As temperature drops, water becomes less soluble in fuel, with the result that water andfuel separate, and water seeks the lowest point in the fuel system or accessory. Iftemperature drops sufficiently, water freezes in the fuel and forms tiny needle-shapedcrystals which may impinge on strainers and restrict fuel flow. In extreme cases fuel flowmay be blocked entirely. This condition is evidenced by a drop in fuel pressure to the powersection. The remedy for this condition is to apply heat to affected components.

In cold weather, it is most important that all fuel pumps and strainers be thoroughlyinspected prior to flight. As long a fuel flows freely from drains in tank and strainers, it canbe assumed that the system is free of ice. Any indication of restricted flow is cause for heatapplication. Collect all drainage in a clear container, and inspect for water globules in thefuel.

A similar condition may exist in lubrication systems, with water coming from condensationin oil tanks or power section casings.

(3) Precipitation

Performance checks and engine adjustments should not be attempted in moderate to heavyprecipitation. Water, snow or ice entering engine inlets causes changes in power outputproportional to the amount entering the affected power section. Power output changes areminor, but not insignificant. Freezing rain and slushy snow have the same effect on poweroutput, and may cling to inlet ducts and screens and upset air flow to the affected powersection.

E. Fuel

It is recommended that testing be carried out with the same fuel as is used in service (Ref.SB5144).

F. Instruments

Testing procedures described depend, for their effectiveness, on the accuracy of cockpitinstrumentation. Instruments should be calibrated frequently to ensure continued accuracywithin the following limits:

Ambient temperature ±1°F

Ambient pressure ±0.05" Hg

Ng and Nf rpm ± 0.5%



Tt5 temperature ± 5°C (9°F) (system accuracy)

Torquemeter ± 7 lb.ft. (system accuracy)

2. Ground Operating Limits

The ground operating limits for each power section are as shown in Table 501.

Limits quoted apply for Standard Day Conditions unless otherwise stated.

If during testing procedures, overtemperature, overspeed or overtorque conditions occur, refer toSpecial Condition Inspection Procedures (Ref. 72-00-00, INSPECTION/CHECK) for the applicableaction to be taken.

NOTE: 1. Overtemperatures are usually preceded by an excessively rapid rise in fuel flow,compressor speed and inter-turbine temperature. Most commonly they are caused byexcessive fuel in the combustion area prior to light-up. Several momentary highovertemperatures affect power section life just as seriously as a single prolonged lowerovertemperature.

NOTE: 2. Serious damage to power sections occurs sooner at higher temperatures. When anovertemperature has occurred, or is anticipated, carry out a normal power sectionshutdown. Avoid an emergency shutdown, unless it appears that continued operation willresult in greater damage than is normally associated with an overtemperature.

NOTE: 3. For approved oils and fuels refer to SB5001 and SB5144 respectively.

3. Ground Testing Procedures

NOTE: For complete operating parameters refer to airframe manufacturer's Flight Manual

A. General

The object of ground testing is to test an engine for mechanical soundness and to ensure thatapplicable ground operating parameters are within limits.

To eliminate unnecessary ground running and thus conserve fuel, ground testing procedures aredivided into the thirteen checks detailed in Para. C. through N.. These checks are not intendedto be carried out as routine periodic checks on an engine but as required in the following cases:

- After component repair or replacement, in accordance with the sequence shown in Table502.- Whenever required as part of troubleshooting (Ref. 72-00-00, FAULT ISOLATION).- As specified by the Aircraft Manufacturer.- At the discretion of the operator.

Table 501 Ground Operating Limits - PT6T-3D/-3DE/-3DF Engines

OperatingConditions(6) (8)

MaxObsITT °C

GasGeneratorSpeed

OutputShaftSpeed

OilPressure(PSIG)(4)

OilTemperature(°C) (7)

NgRPM

NsRPM

P/S RGB P/S (3) RGB (3)

No Load 600 24500(64.2%)

6930(1)

40min.

40 min(5)

-54 to +115

-54 to +115

Starting 1090(2)

-54 Min.(3)

-54 Min (3)

NOTE: 1. The output speed is limited to 6930 rpm (105%) at NO LOAD condition.Transient overspeed (105%<Nf<=110%) is limited to 10 seconds.



OperatingConditions(6) (8)

MaxObsITT °C

GasGeneratorSpeed

OutputShaftSpeed

OilPressure(PSIG)(4)

OilTemperature(°C) (7)

NOTE: 2. This value is time-limited (Ref. 72-00-00, INSPECTION/CHECK).

NOTE: 3. Minimum oil temperature for starting is -40°C (-40°F) for 5 C/S (Type II)oil and -53.9°C (-65°F) for 3 C/S (Type I) oil.

NOTE: 4. These pressure limits apply to normal operating temperatures. Duringextremely cold starts, oil pressure may reach 300 psig.

NOTE: 5. This limit is the minimum oil pressure at 4400 rpm (Ns).

NOTE: 6. Engine inlet condition limits for engine operation:Temperature: -54°C (-65°F) to 57.5°C (135°F)Altitude: sea level to 20,000 ft.

NOTE: 7. For operating conditions with ambient temperatures more than 43 °C (110°F), the maximum permitted oil temperature is 120 °C (248 °F). If more thanthe limits, do an inspection (Ref. 72-00-00, INSPECTION/CHECK).

NOTE: 8. Fuel viscosity limit for cold starting is 12 centistokes maximum.

Table 502 Checks after Component Repair or Replacement

COMPONENT REPLACED CHECKS REQUIRED(PARA. REF. NO.)

Power Section 3.C., D., E.*, F., G., H., I., J., K., L., N.

Reduction Gearbox 3.E.*, G., H., J.,, L., N.

T5 Temperature Compensator 3.F.

Automatic Fuel Control Unit (AFCU) 3.C., D., E.*, G., H., I., J., K., L., N.

Manual Fuel Control Unit (MFCU) 3.C., D., G., H., I., N. (Ref. NOTE 2)

Fuel Pump 3.C., D., G., H., I., J., K., L., N.

Power Turbine (NF) Governor 3.E.*, G., H., J., K., N.

Ignition Exciter 3.G., H., N.

Torque Limiter 3.E.*, G., H., K., N.

Flow Divider and Dump Valve 3.C., D., G., H., K., N.

Oil-to-Fuel Heater 3.G., H., K., N.

Compressor Bleed Valve 3. H., K., N.O.

NOTE: 1. Where marked with an asterisk (*) , Pneumatic system pressure test (Para.3.E.) should only be carried out if an air leak is suspected.

NOTE: 2. Checks 3. C. D. and H. on manual fuel control unit must be carried out in



COMPONENT REPLACED CHECKS REQUIRED(PARA. REF. NO.)

manual mode.

Table 503 Ground Testing- Definition and Location

Paragraph Check Paragraph Check

3.C. Wet Motoring Run 3.I. Max. Ng. and ManualAutomatic InterconnectLinkage Adjustment

3.D. Dry Motoring Run 3.J., Power Turbine(Nf) Governors

3.E. Pneumatic System PressureTest

3.F. Tt5 Temperature CompensatorVerification

3.K. Performance/Power Assurance

3.G. Pre-start Checks 3.L. Acceleration Check

3.H. Starting 3.M. Deceleration Check

3.N. Shutdown 3.O. Bleed Valve Closing Point

B. Equipment Required (Ref. Table 504)(1) The equipment required for ground testing as follows:

Table 504 Ground Testing - Equipment Required

ITEM NO. PART NO./SPECIFICATION NOMENCLATURE/PROCEDURE

Special Tools

P/N 3243781 (Pre-SB5331)

(Ref. TOOLS/FIX/EQUIP, Table ) SLAVE STOP

(PWC70797) Adapter, P3 LeakCheck

CONSUMABLEMATERIALS

(Ref. CONSUMABLEMATERIALS)

WARNING: READ MATERIAL SAFETY DATA SHEETS BEFORE USING THESEPRODUCTS

(PWC09-002A) MIL-S-22473 Loctite, Grade H or 222

(PWC05-007) Leak-Tec 372 Leak Checking Fluid

C. Wet Motoring Run(1) Power Control Lever - FUEL CUT-

OFF.(2) Ignition Switch -

OFF.(3) Fuel Control Selector Switch -



AUTOMATIC.(4) Fuel Shut-Off Valve -

OPEN.(5) Fuel Boost Pump Switch - ON. Check fuel

pressure.(6) Starter Switch -

ON.

WARNING: IF THERE ARE ANY INDICATIONS OF A FIRE AT THIS POINT, CLOSE THEFUEL SHUT-OFF VALVE AND CONTINUE MOTORING RUN.

(7) When Ng reaches 12%, set Power Control Lever toIDLE.

(8) Maintain starter operation for the required duration (Approx. 15seconds).

NOTE: Observe starter limits (Ref. Aircraft Flight Manual).(9) Check for fuel

leaks.(10)Power Control Lever - FUEL CUT-OFF.(11)Starter Switch - OFF.(12)Check that dump valves and gas generator drain valves operate correctly by observing

overboard drain.(13)Fuel Boost Pump Switch - OFF.(14)Fuel Shut-off Valve - CLOSED.(15)Allow the required cooling period for starter before attempting any further operation (Ref.

Aircraft Flight Manual).

D. Dry Motoring Run

NOTE: The following procedure is used as required to clear a power section of trapped fuel andvapor or in the event of fire in a power section. During the motoring run, the airflowthrough the power section purges the fuel vapor or fire from the combustion, gasgenerator, turbine and exhaust sections.

(1) Power Control Lever - FUEL CUT-OFF.

(2) Ignition Switch -OFF.

(3) Fuel Control Selector Switch -AUTOMATIC.

(4) Fuel Shut-off Valve -OPEN.

(5) Fuel Boost Pump Switch - ON. Check fuelpressure.

(6) Starter Switch -ON.

WARNING: IF THERE ARE ANY INDICATIONS OF A FIRE AT THIS POINT, CLOSE THEFUEL SHUT-OFF VALVE AND CONTINUE MOTORING RUN.

(7) Maintain starter operation for the desired duration.

NOTE: Observe starter limits (Ref. Aircraft Flight Manual).

(8) Starter Switch -OFF.



(9) Fuel Boost Pump Switch -OFF.

(10)Fuel Shut-off Valve - CLOSED.(11)Allow the required cooling period for starter before attempting any further starting

operating (Ref. Aircraft Flight Manual).

E. Pressure Test of Fuel Control Pneumatic System (Ref. Fig. 502)Figure 502 Pressure Test of Fuel Control Pneumatic System



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1. Tube Assembly 2. Adapter 3. Pressure Gage 4. Elbow 5. Tube Assembly 6. Locknut 7. Tube Assembly



(1) Do the pressure test of fuel control pneumatic system by one of the following methods:(a) Method A:

1 Disconnect the P3 tube coupling from elbow at front fireseal.2 Blank off coupling on heated tube assembly.3 Connect a 75 to 85 psig clean and dry air supply to the elbow (4) at the fireseal.4 Apply leak checking fluid (PWC05-007) to all connections in the fuel control

pneumatic system.

NOTE: Slow bubbling is permitted only at the AFCU joints that follow:

• Between P3 inlet adapter and drive body assembly• Nuts and main body assembly• Cover and main body assembly

No other leakage is permitted.

5 If leaks are detected, examine the components for defects and replace as necessary.

NOTE: Retorque connections as required and repeat check.6 Wipe all leak checking fluid from connections.7 Disconnect air supply.8 Connect P3 tube coupling to elbow at front fireseal, torque 90 to 100 lb.in. and

lockwire.

(b) Method B (Alternate procedure with P3 leak check adapter (PWC70797)):1 Remove the P3 filter bowl and filter element from the power section.2 Install adapter (PWC70797) and tighten with your fingers.3 Connect a 75 to 85 psig clean and dry air supply to the adapter (PWC70797).4 Apply leak checking fluid (PWC05-007) to all connections in the fuel control

pneumatic system.

NOTE: No other leakage is permitted, slow bubbling is permitted at the followingjoints only:

• Between adapter and drive body assembly• Nuts and main body assembly• Cover and main body assembly

5 If leaks are detected, examine the components for damage and replace asnecessary.

NOTE: Retorque connections as required and repeat check.6 Clean all leak checking fluid from connections.7 Disconnect air supply.8 Remove the adapter (PWC70797).9 Install again the P3 filter bowl and filter element.

F. Tt5 Temperature Compensator Verification

NOTE: The Tt5 temperature compensator may be checked with engine running as detailed instep (1) following or by using a tester to simulate operating conditions as detailed instep (2) .



(1) Verification with engine running.(a) Note amount of trim indicated on trim value plates on center fireseal and on gas

generator case in intake plenum area (Ref. Fig. 503).



Figure 503 Location of Trim Value Plates(SHEET 1 OF 2)

Pre-SB5509

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(SHEET 2 OF 2)

Post-SB5509

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1. Air Inlet Screen 2. Tt5 Trim Value Plate (1 ea) 3. Power Section Data Plate (1 ea) 4. Center Fireseal 5. Gas Generator Case 6. T5 Trim Value Plate



(b) Start power section (Ref. Para. G.and H.) following.(c) Run for five minutes at a minimum of 75% Ng (90% optimum) to allow stabilization of

operating parameters.(d) Disconnect power supply lead from temperature compensator (Ref. Fig. 504)



Figure 504 T5 Temperature Compensator Adjustment

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NOTE: Tt5 indicated should rise by an amount equal to trim. If necessary removeprotective cap from adjuster and adjust as required.

(e) Reconnect power supply lead to compensator.(f) Repeat check as necessary until correct adjustment is achieved.(g) Install protective cap on adjuster and lockwire.

(2) Verification using tester (engine not running)

NOTE: This check requires the use of a Barfield Tester 2312G-8 or equivalent. The testermay be obtained from the following address.Barfield Inst. Corp.,4101 N.W. 29th St.Miami, FL 33142 USA

(a) Note amount of trim indicated on trim value plates on center fireseal and on gasgenerator case in intake plenum area (Ref. Fig. 503).

(b) Disconnect Tt5 thermocouple input lead from compensator.(c) Using suitable connector, connect tester to compensator.(d) Supply 28 VDC to compensator.(e) Adjust tester to obtain reading of 750°C on cockpit instrument.(f) Disconnect power supply lead from temperature compensator.

NOTE: Tt5 indicated should rise by an amount equal to trim. If necessary, removeprotective cap from adjuster and adjust as required.

(g) Reconnect power supply lead to compensator and observe that reading returns to750°C.

(h) If necessary, repeat steps (e) and (f).(i) Disconnect tester and reconnect input lead.(j) Install protective cap on adjuster and lockwire.

G. Pre-start Checks(1) Inspect air inlets thoroughly, and ensure that they are clear of loose nuts, bolts, tools and

other objects which might cause damage and subsequent failure.(2) Inspect area in vicinity of air inlets and exhaust, and remove any loose objects which might

possibly be ingested or blown rearward by exhaust gases.(3) Check for evidence of oil leaking into air

intakes.(4) Check each power section fuel system for presence of

water.(5) Check engine controls for full travel, freedom of movement and correctness of

direction.(6) Check oil level in each power section and reduction gearbox oil tank and service as

necessary.

H. Starting

NOTE: 1. Each power section may be started with its fuel system in MANUAL or AUTOMATICmode. However it is recommended that the AUTOMATIC mode be used.

NOTE: 2. Refer to step (3) following for unsatisfactory start conditions.

NOTE: 3. Refer to Tables 505 and 506 for power section/reduction gearbox operating oilpressures and temperatures.



Table 505 Power Section - Operating Oil Pressure and Temperature

Operation below 79% Ng Operation above 79% Ng

40 to 80 psi 80 to 115 psi

0°C to 115°C 0°C to 115°C

NOTE: 1. At oil temperature 82°C to 93°C (180°F to 200°F) and Ng speed of 90.5 % (34500rpm), set oil pressure between 90 to 100 psi (nominal) by adding or removingspacers from main oil pressure regulating valve (Ref. 79-20-05).

NOTE: 2. For operating conditions with ambient temperatures more than 43 °C (110 °F), themaximum permitted oil temperature is 120 °C (248 °F). If more than the limits, doan inspection (Ref. 72-00-00, INSPECTION/CHECK).

Table 506 Reduction Gearbox - Operating Oil Pressure and Temperature

Operation below 94% Nf Operation above 94% Nf

40 to 60 psi 60 to 80 psi

0°C to 115°C 0°C to 115°C

NOTE: 1. At oil temperature 82°C to 93°C (180°F to 200°F) and Nf speed of 97% set oilpressure between 65 to 75 psi by adding or removing spacers from reductiongearbox oil pressure relief valve (Ref. 72-10-00).

NOTE: 2. For operating conditions with ambient temperatures more than 43 °C (110 °F), themaximum permitted oil temperature is 120 °C (248 °F). If more than the limits, doan inspection (Ref. 72-00-00, INSPECTION/CHECK).

(1) AUTOMATIC mode start procedure.(a) Power Control Levers - FUEL CUT-OFF.(b) Power Turbine Governor Setting - Anywhere in operating range.(c) Master Switch - ON.(d) Fuel System Shut-off Valves - OPEN.(e) Fuel Boost Pump Switches - ON (Check power section fuel inlet pressure 5 psig

minimum).(f) Aircraft Bleed Air - OFF.(g) Electrical Generators - OFF.(h) Fuel Control Selector Switch - AUTOMATIC.(i) Starter Switch - ON.

CAUTION: IF LIGHT UP IS NOT OBTAINED WITHIN 15 SECONDS OF THE POWERCONTROL LEVER BEING PLACED IN “IDLE” POSITION, SET POWERCONTROL LEVER TO “FUEL CUT OFF” AND SWITCH OFF STARTER ANDIGNITION. WAIT FOR ROTATION TO STOP COMPLETELY. AFTER A 30SECOND FUEL DRAINING PERIOD CARRY OUT A 15 SECOND DRYMOTORING RUN (REF. PARA. D. PRECEDING) BEFORE ATTEMPTINGANOTHER START. REPEAT COMPLETE STARTING SEQUENCEOBSERVING STARTER LIMITS (REF. AIRCRAFT FLIGHT MANUAL).

(j) Power Control Lever - IDLE after stabilized Ng (gas generator speed) of not less than12% is reached.



(k) Observe that gas generator accelerates to Idle rpm (51% minimum), and that nominalinter-turbine starting temperature is not exceeded (Ref. Table 501) .

(l) When Ng attains Idle rpm:

Starter Switch - OFF

(m) Check oil pressures (Ref. Table 501)(n) Check clutch engagement.

1 Start second power section.2 Slowly increase power on second power section until equal power turbine speed (Nf)

on both power sections is obtained.3 Check that small power increases on one power section produce equal Nf increases

on both power sections, this indicating that both clutches are engaged.

NOTE: If a clutch fails to engage, carry out the procedures detailed in (3) (e).

CAUTION: ELECTRICAL GENERATORS MUST NOT BE SWITCHED ON UNTIL Ng ISAT LEAST 71 %.

(o) After successful start of both power sections:

Electrical Generators - ON (as required)Bleed Air - ON (as required)

(2) MANUAL mode start procedure.

CAUTION: IN MANUAL MODE, MAJOR ENGINE PARAMETERS, i.e. Ng, Nf ANDTORQUE, ARE NOT LIMITED AUTOMATICALLY. CONSEQUENTLY INTHIS MODE THE OPERATOR MUST MONITOR ENGINE INSTRUMENTS,MAKE CHANGES IN POWER SETTINGS GRADUALLY AND EXERCISE THEADDITIONAL SKILLS REQUIRED TO ENSURE THAT OPERATING LIMITSARE NOT EXCEEDED.

(a) Power Control Lever - FUEL CUT-OFF.(b) Power Turbine Governor Setting - Anywhere in operating range.(c) Master Switch - ON.(d) Fuel System Shut-off Valves - OPEN.(e) Fuel Boost Pump Switches - ON (check power section fuel inlet pressure 5 psig

minimum).(f) Aircraft Bleed Air - OFF.(g) Electrical Generators - OFF.(h) Fuel Control Selector Switch - MANUAL.(i) Starter Switch - ON.

CAUTION: IF LIGHT UP IS NOT OBTAINED WITHIN 15 SECONDS OF THE POWERCONTROL LEVER BEING PLACED IN “IDLE” POSITION, SET POWERCONTROL LEVER TO “FUEL CUT OFF” AND SWITCH OFF STARTER ANDIGNITION. WAIT FOR ROTATION TO STOP COMPLETELY. AFTER A 30SECOND FUEL DRAINING PERIOD CARRY OUT A 15 SECOND DRYMOTORING RUN (REF. PARA. D. PRECEDING) BEFORE ATTEMPTINGANOTHER START. REPEAT COMPLETE STARTING SEQUENCEOBSERVING STARTER LIMITS (REF. AIRCRAFT FLIGHT MANUAL).

(j) Power Control Lever - IDLE after stabilized Ng (gas generator speed) of not less than12% is reached.



(k) Observe that gas generator accelerates to Idle rpm (51% minimum), and that nominalinter-turbine starting temperature limits are not exceeded (Ref. Table 501) .

(l) When Ng attains Idle rpm:

Ignition Switch - OFFStarter Switch - OFF

(m) Check oil pressures (Ref. Table 501)

CAUTION: ELECTRICAL GENERATORS MUST NOT BE SWITCHED ON UNTIL Ng ISAT LEAST 71%. IN MANUAL MODE IT WILL BE NECESSARY TO ADJUSTTHE POWER CONTROL LEVER TO MAINTAIN DESIRED Ng WITHCHANGES IN ELECTRICAL GENERAL LOAD.

(n) Check clutch engagement.1 Start second power section.2 Slowly increase power on second power section until equal power turbine speed (Nf)

on both power sections is obtained.3 Check that small power increases on one power section produce equal Nf increases

on both power sections, this indicating that both clutches are engaged.

NOTE: If a clutch fails to engage, carry out procedures detailed in (3) (e)following.

(3) An unsatisfactory start will occur if one or more of the following take place:

CAUTION: IF Tt5 CONTINUES TO RISE, OR IF GREATER THAN NORMAL FUELFLOW IS OBSERVED WHEN POWER CONTROL LEVER IS SET TO “IDLE”,A HOT START MAY BE ANTICIPATED. THE OPERATOR MUST BEPREPARED TO ABORT START BEFORE Tt5 STARTING TEMPERATURELIMITS ARE EXCEEDED.

CAUTION: FOLLOWING AN UNSATISFACTORY START, OR IN THE EVENT OF FIRE,THE AFFECTED POWER SECTION MUST BE CLEARED BY PERFORMINGA DRY MOTORING RUN (REF. PARA. D. PRECEDING).

(a) Hot Start - Interturbine temperature (Tt5) exceeds starting temperature limits.

NOTE: A hot start may also be caused by a False Start or a Hung Start.(b) False or Hung Start - After light-up has occurred, gas generator speed does not reach

51% within 30 seconds of Power Control Lever being set to IDLE.(c) No Start - Power section does not light up within 15 second of Power Control Lever

being set to IDLE.

NOTE: Light-up is indicated by a rise in interturbine temperature. Actual time to light-up is dependent upon ambient temperature and the amount of torque suppliedby the starter.

(d) Power section oil pressure fails to reach 40 psi minimum.(e) Sprag clutch of second power section started, fails to engage. In the event of clutch

non-engagement, proceed as follows:1 Hold power section with the normally engaged clutch at its stabilized speed - do not

decelerate.

CAUTION: IF CLUTCH ENGAGES DURING POWER SECTION RUNDOWN, THEREDUCTION GEARBOX MUST BE REMOVED AND INSPECTED BY ANOVERHAUL FACILITY.

2 Shut down power section with the non-engaged clutch and allow rotation to stop.



3 Shut down remaining power section and allow rotation to stop.4 Start power section with previously non-engaged clutch and listen carefully for

unusual noises indicating a damaged clutch.5 If audible indications are noted, the reduction gearbox must be removed and

inspected by an overhaul facility.6 If engagement is normal, start other power section.7 Run the power section with the suspect clutch, at Flight Idle for five minutes.8 Shut down power section and inspect reduction gearbox output section oil filter and

chip detector.

NOTE: If condition of oil filter and chip detector is satisfactory, the engine mayremain in service.

I. Maximum Ng and Manual-Automatic Interconnect Linkage Adjustment (Ref. Fig. 505)Figure 505 Fuel Control Adjustment



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WARNING: ENSURE THAT THE AIRCRAFT IS PROPERLY TIED DOWN (REF. AIRCRAFTFLIGHT MANUAL).

NOTE: 1. The maximum gas generator speed adjustment and the manual-automaticinterconnect linkage adjustment affect each other. Hence, the entire procedure inthis check must be carried out whenever either of these adjustments requireschecking.

NOTE: 2. To ensure the capability of setting the gas generator maximum speed stop under awide variety of ambient conditions without exceeding engine operating limits, aslave part power trim stop (P/N 3243781, Table 504) (Pre-SB5331) or integral partpower trim stop (Post-SB5331) is provided. The part power trim stop, when in use,enables adjustment of the maximum obtainable Ng at lower power settings.

NOTE: 3. During adjustment of the gas generator maximum speed stop, ensure the followingconditions:

• The internal threads of the index lever are fully engaged.• The stop screw touches the part power trim stop in the "in use" position or in the

"stowed" position.• The locking nut and screw are correctly locked and lockwired.

(1) Pre-SB5331: Install slave part power trim stop (P/N 3243781, Table504).

WARNING: EACH PART POWER TRIM STOP MUST BE PROPERLY STOWED AFTERCOMPLETION OF THE PART POWER TRIM CHECK.

(2) Post-SB5331: Remove pin securing part power trim stop in stowedposition.

(3) Rotate stop so that it limits travel of automatic fuel controlarm.

(4) Install cotterpin to secure stop and bend ends of pinover.

(5) Start power section and proceed as follows:(a) Fuel Control Selector Switch - AUTOMATIC.(b) Set Power Control Lever so that arm contacts stop.

CAUTION: ADJUST COLLECTIVE PITCH RESET SETTING AS NECESSARY TOENSURE THAT MAXIMUM OUTPUT SHAFT SPEED IS NOT EXCEEDED(REF. TABLE 501) .

(c) Gradually increase collective pitch until maximum possible Ng is obtained.

NOTE: Ensure that torque limit is not exceeded (Ref. Airframe Manual).(d) Check that Ng falls within 35052 rpm (92.0%) to 35280 rpm (92.6%) with slave (Pre-

SB5331) or integral (Post-SB5331) part power trim stop.(e) If necessary, adjust automatic fuel control arm maximum stop adjuster (1) to get Ng

value of 35166 rpm (92.3%) with slave part power trim stop (2).

NOTE: A half-turn of adjuster is equal to a change of 225 rpm (0.5%) approx. Turncounterclockwise to increase rpm or clockwise to decrease rpm.

CAUTION: Pre-SB5331: SLAVE PART POWER TRIM STOP MUST NOT BE REMOVEDUNTIL MAXIMUM STOP ADJUSTMENT HAS BEEN COMPLETED. FAILURETO OBSERVE THIS PRECAUTION COULD CAUSE AN Ng OVERSPEED.



CAUTION: Post-SB5331: PART POWER TRIM STOP MUST NOT BE STOWED UNTILMAXIMUM STOP ADJUSTMENT HAS BEEN COMPLETED. FAILURE TOOBSERVE THIS PRECAUTION COULD CAUSE AN Ng OVERSPEED.

(f) Shut down power section.(g) On completion of adjustment, lockwire adjuster.(h) Pre-SB5331: Remove cotterpin and slave part power trim stop.(i) Post-SB5331: Remove cotterpin and rotate part power trim stop to the stowed position.(j) Post-SB5331: Secure stop with a new pin and bend ends of pin over.

(6) Check that pointer on MFCU indicates 95 degrees. If not, adjust manual-automaticinterconnect linkage (4) as follows:(a) With indicator at zero degrees (minimum stop), retard automatic fuel control arm to

compress spring and to disengage spacer tangs from self-locking nut.(b) Adjust self-locking nut position as required and recheck indicator against 95 degree

position.

NOTE: Ensure that spacer tangs are correctly positioned on nut flats and betweentangs of interconnect lever (Ref. Detail B).

(7) Hold the automatic fuel control arm in contact with maximum stop. Do a check for clearance(3) between MFCU arm maximum stop adjuster (5) and maximum stop. The clearance mustbe 0.015 to 0.020 in.

NOTE: It is recommended that rigging of the interconnect linkage is done with the airframecontrol tube disconnected at the MFCU lever (Ref. Airframe Maintenance Manual).

(a) If necessary, adjust manual-automatic interconnect linkage (4) to obtain the requiredminimum clearance - no other adjustment is permitted.

NOTE: Ensure that torque required to turn adjustment nut is 1-1/2 lb.in., minimum. Ifnecessary, replace nut.

(b) Retard Power Control Lever setting until MFCU minimum stop is contacted.(c) Ensure that pointer is not bent. Straighten if necessary.(d) If pointer deviates from 0 degrees by more than 1/16 (0.0625) in., MFCU must be

replaced.

(8) Start power section and run atIdle.

(9) Carry out several transfers from Automatic to Manual and viceversa.

(10)Check that successful transfer has taken place in both directions by observing shift ofparameters.

NOTE: 1. Mild surges or pops during transfer may be considered as normal.

NOTE: 2. If operator flies below 5000 ft., ground check as above is acceptable. If operatorflies above 5000 ft., the cross over must be checked as per Aircraft MaintenanceManual.

(11)Check and adjust AFCU Idle setting.(a) Start affected power section.(b) Set Power Control Lever to position pointer on MFCU at 30 to 35 degrees on quadrant.(c) Check that Ng is between 20500 (53.8%) and 21000 rpm (55%).(d) If necessary, adjust idle stop (7) to bring Ng within required range.

NOTE: The difference between Ng idle speeds of both power sections must not exceed



250 rpm.(e) On completion of check, torque idle stop locknut 20 to 25 lb.in. and lockwire.

J. Power Turbine (Nf) Governors

For instructions on setting the Nf governor maximum and minimum stops, refer to the AircraftMaintenance Manual.

K. Performance/Power Assurance Check

The purpose of the performance/ power assurance check is to detect any signs of enginedeterioration.

All forms of engine deterioration can cause increased Tt5 and fuel consumption at a given poweroutput. Compressor deterioration which in most cases, is due to dirt deposits, causes increase ofNg at given power settings. This can be remedied by Field Cleaning (Ref. 72-00-00, ENGINE -CLEANING). Hot section deterioration, in addition to causing Tt5 increases, causes decreases, inNg at given power settings.

The performance parameters of an installed engine are significantly influenced by the physicalaspects of the installation. For this reason, operators who need to do a power assurance orperformance checks on an engine must refer to the procedures detailed in the applicableRotorcraft Flight Manual.

If the observed parameters are outside the limits quoted for the installed engine, instrument orengine faults are indicated and reference must be made to the applicable troubleshootingprocedures (Ref. 72-00-00, FAULT ISOLATION).

L. Acceleration(1) Start power section and operate to obtain stabilized

temperatures.(2) Fuel Control Selector Switch -

AUTOMATIC.(3) Increase power to obtain Ng of 61 ±

1%.

CAUTION: POWER CONTROL LEVER MUST BE RETARDED TO “IDLE” AS SOON AS90% Ng IS ATTAINED.

(4) Rapidly (0.5 second max.) advance Power Control Lever to maximum setting and retard assoon as 90% Ng is reached.

(5) Record time taken to accelerate to 90% Ng. Maximum acceptable time is 4 seconds, with nomore than 0.5 seconds between power sections.

NOTE: The maximum acceleration time of 4 seconds may be increased 1.0 second for each5,000 ft. (1525M) pressure altitude above sea level and/or 0.5 second for each30°C outside temperature above 15°C.

(6) If acceleration time exceeds limits, the acceleration adjuster on fuel control unit may beadjusted, as follows:

CAUTION: TO AVOID OVER ADJUSTMENT, ALL ADJUSTMENTS MUST BE LOGGED.

(a) Adjuster must be rotated one click at a time, to a maximum of six clicks counter-clockwise (to slow acceleration rate) and three or six clicks (see Note) clockwise (tospeed up acceleration rate), repeating steps (3) and (4) after each adjustment.

NOTE: Three clicks are allowed if the adjuster has a flat, "coin" shaped lockwire seal.Six clicks are allowed if the adjuster has a small cylindrical seal.

(b) If acceleration time is not met within these parameters, the AFCU must be replaced.

M. Deceleration (Pre-SB5398 engines only)



CAUTION: REFER TO AIRCRAFT FLIGHT MANUAL FOR COMPLETE STARTING ANDGROUND RUNNING PROCEDURES.

(1) With the engine running at ground idle, advance (rotate) the throttle of one power sectionto full throttle position and allow Ng to stabilize.

(2) Retard throttle as quickly as possible (approximately one second), allowing the powersection to decelerate to idle speed.

(3) Repeat steps (1) and (2) for the second powersection.

(4) Replace the fuel surge accumulator if engine flame-out, rumble, or compressor stall occursduring the rapid deceleration check.

N. Shutdown

WARNING: IF THERE IS ANY EVIDENCE OF FIRE IN A POWER SECTION AFTERSHUTDOWN, PROCEED IMMEDIATELY WITH A DRY MOTORING RUN (REF.PARA. D. PRECEDING)

(1) Power Control Lever -IDLE.

(2) Allow both power sections to stabilize for a minimum of one minute atIdle.

(3) Power Control Lever - FUEL CUT-OFF.

(4) Check for any changes in run-down time, which should not be less than 20 seconds fromIdle and listen for any unusual noises such as scraping, rubbing or grinding.

(5) Fuel Boost Pump -OFF.

(6) Fuel Shut-off Valve -CLOSED.

(7) Check that dump valves and gas generator drain valves operate correctly by observingoverboard drain.

(8) Check engine for fuel and/or oil leaks (Ref. Table 507).

NOTE: If engine is scheduled to remain inactive for an extended period, install inlet andexhaust covers after a suitable cool-down period.

Table 507 Engine Oil and Fuel Permissible Leakage

Overboard Drain Leakage

Fuel (Each Power Section)

Fuel Pump 0.5 cc/minute (30 cc/hour) Maximum

Dump Valve 0.5 cc/minute (30 cc/hour) Maximum

Oil

Starter Generator Seal (each) 3 cc hour Maximum

Output Shaft Seal 0.2 cc/minute (12 cc/hour) Maximum

NOTE: 1. Where a specific seal leakage is not specified, seal leakage must notexceed 3 cc/hr.

NOTE: 2. Oil consumption is 0.4 lb./hr (182 cc/hr) for the complete engine or 0.2lb./hr (91 cc/hr) for each power section or 0.1 lb./hr (45 cc/hr) for the



Overboard Drain Leakage reduction gearbox. All oil consumption measured over a 10 hours period.

O. Bleed Valve Closing Point(1) Perform Bleed valve closing point (Ref. 75-30-00 Adjustment/

Test).



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