FIT FOR FLIGHT II Lecture notes and practice MODULE 3 ...

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Letalska angleščina II

FIT FOR FLIGHT II Lecture notes and practice

MODULE 3: AIRCRAFT SYSTEMS

NIKA ZALAZNIK

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CONTENTS

3 AIRCRAFT SYSTEMS ............................................................................... 3

3.1 FUEL SYSTEM ......................................................................................................... 3 3.2 ELECTRICAL SYSTEM ......................................................................................... 12 3.3 HYDRAULIC SYSTEM .......................................................................................... 16 3.4 LANDING GEAR .................................................................................................... 23

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3 AIRCRAFT SYSTEMS

Background information

As the demand for air travel increases so will the demand for aircraft maintenance engineers.

This is the age of skilled engineers, people who can work with their minds as well as

their hands. A modern aircraft is composed of many thousands of components and systems,

such as:

•Hydraulic systems to activate flight controls, landing gear, reverse thrust

•Propulsion systems such as piston, gas turbine and jet engines

• Electronic systems such as navigation, communications, instrumentation.

Engineers ensure that maintenance, inspection and calibration tasks are completed regularly to

ensure continuous safe and efficient flight operations across the world.

In this unit you will:

- learn how to put the language of airframe systems into context

- develop reading skills

- discuss the a/c systems

- learn and remember new technical vocabulary

- listen practice using technical language

3.1 FUEL SYSTEM

Aircraft fuel systems are complex, involving interaction between the fluid, mechanical and

electrical systems on-board an aircraft. It is vital these systems perform as intended and within

regulations and without adversely impacting other areas of an aircraft’s system performance.

The 111,000 kg (245,000 lb) fuel capacity of the A330 MRTT enables the aircraft to perform

its missions without any additional fuel tank. The fuel is carried in six tanks each formed as

an integral part of the standard A330-200 structure:

An inner and outer tank in each wing

A tank in the wing centre section

A trim tank in the horizontal stabilizer

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There is an optional capability available for the A330 MRTT to carry two types of fuel so that

it can refuel aircraft using different fuel types during the same mission.

The A330 wing is large enough to hold all the fuel needed to make the A330 MRTT a high

performing tanker without impairing the fuselage capacity to carry passengers and/or cargo.

Work in pairs. Provide Slovenian translations for the terms in the illustrations above

and answer these questions.

What is the exact location of fuel tanks?

What is the maximum fuel capacity?

What types of fuel does the A330 use?

Are there any additional fuel tanks? What is their purpose?

An auxiliary fuel pump used in an aircraft fuel system to provide fuel at the required pressure

to the carburettor or to the fuel-metering unit of a fuel injection system. The pump also is

meant to purge the fuel lines of any vapours, to prime the cylinders for start up, and to supply

fuel if the engine-driven pump fails.

Answer these questions.

What is difference of fuel pump module and fuel pump?

What do fuel pump do?

How do you get at the fuel pump?

How do you get to the fuel pump?

How do fuel boost pumps work?

Read the dialogue and do the tasks below.

P: There certainly is a lot of plumbing in this aircraft.

M: Yes, and we’ll have a look at all of it. It isn’t as complicated as some airplanes,

though.

P: How could it be much more complicated?

M: Well, it could have single-point fuelling, for instance. Or, it could have a wet-wing

instead of bladders for fuel cells.

P: I suppose you’re right. What are you looking for in the fuel system?

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M: We’ll check everything from the fuel caps to the fuel control.

P: Let’s see. That means checking the fuel lines, the fuel selector, and the boost pumps.

M: It means a little more than that. The drain cocks have to be checked, and all the

sediment has to be removed from the fuel strainers. We’ll check the cross-feed system,

and we’ll make sure the vents are open.

P: That’s a lot of checking. Is there anything else?

M: Yes. The fuel quantity probes must be checked and calibrated, and we’ll have to make

sure the vent lines are open.

P: I just thought of something else: the transfer pumps.

M: Right. We’re really looking for anything that could cause a fire in the fuel system. This

fuel can cause a pretty hot fire.

P: We don’t want any fire except where it belongs – in the engines. Let’s make sure our

dry-wing really is dry. By the way, don’t you want me to leave you alone so you can

get your job done?

M: You’re not bothering me. I’ll be happy to have you watch the whole inspection if you

have the time.

P: Oh, I have the time. It’s a real education to see this. I think every pilot should learn

what really makes their airplane work.

M: I agree with you. It would certainly help us mechanics. The squawks we get from

pilots make more sense.

Check your understanding.

1) After reading the dialogue, answer the following questions. Remember, you do

not have to understand every word to answer the questions.

1 What is the dialogue about?

2 What kinds of fuel system are used in a/c?

3 What kind of fuel system is used on the a/c which is discussed in the dialogue?

4 What is the fuel quantity probe?

5 Why do mechanics like pilots to know what makes a/c work?

2) Now study the text carefully and look for the answers to these questions:

1 What has to be checked in the fuel system? Make a list.

2 What has to be calibrated?

3 What has to be removed from the fuel strainers?

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3) Find the technical terms to the following definitions. Help yourself with the list

below.

Slovenian Eng TERM

bladder

boost pump

fuel control

cross-feed system

single-point fuelling

fuel strainer

transfer pumps

fuel quantity probe

plumbing

fuel cap

1 ________________________ is a device which metres the correct flow of fuel into a

jet engine.

2 ________________________ is a system on a multi-engine airplane which allows an

engine to use fuel from any cell.

3 ________________________ is a flexible storage container for fuel.

4 ________________________ is a fuel system with several cells, all of which are filled

from a single point.

5 ________________________ are pumps used to move fuel from one cell to another.

6 ________________________ is a system of tubes which carry fluids.

7 ________________________ is an auxiliary fuel pump used in emergency conditions.

8 ________________________ is a cover for the refuelling holes in fuel cells.

9 ________________________ is a device for measuring the quantity of fuel in a cell.

10 ________________________ is a device used for filtering solid impurities out of the

fuel before it reaches the engine.

Increase your vocabulary.

1) Find words which have the similar meanings to those listed below (refer to the

dialogue).

for instance _________________ be removed from ________________

though _________________ make sure ________________

look for _________________ get your job done ________________

make more sense _________________ by the way ________________

in accordance with _________________ come off ________________

2) Nouns and verbs in avionics

Make verbs out of the following nouns taken from the text.

Noun Verb Slovenian

calibration ____________________________

container ____________________________

fire ____________________________

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run ____________________________

travel ____________________________

move ____________________________

adjustment ____________________________

leak ____________________________

check ____________________________

location ____________________________

measurement ____________________________

maintenance ____________________________

Work in pairs. Match the properties of fuel on the left with the descriptions on the right.

a flash point i How easily an electric current flows through the fuel.

b freezing point ii The temperature at which the fuel ceases to be a liquid and starts to become a solid.

c sulphur content

iii How easily a liquid changes to a vapour and combusts.

d lubricity iv The amount of heat produced when a given quantity of fuel is burned in engine.

e volatility v The ability to make moving parts in the fuel system, such as pumps and valves, operate smoothly.

f electrical conductivity

vi Damage done by the fuel to metal components by chemical reaction.

g net heat of combustion

vii The percentage of sulphur contained in a fuel.

h corrosiveness viii The temperature at which a fuel will give off a vapour that will burn instantly when ignited.

3) Dictionary work.

Try to find Slovenian equivalents for the following technical terms:

Tech term Slovenian Brief definition

bladder __________________________ ____________________________

fuel quantity probe __________________________ ____________________________

dry-wing __________________________ ____________________________

cross-feed system __________________________ ____________________________

vent __________________________ ____________________________

wet-wing __________________________ ____________________________

plumbing __________________________ ____________________________

fuel strainer __________________________ ____________________________

fuel selector __________________________ ____________________________

boost pump __________________________ ____________________________

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Check your grammar.

1 Present Continuous and Present Simple

Look at the following examples:

Present Continuous Present Simple

What are you looking for in the fuel system? I like flying. You're not bothering me. Many older a/c have dry-wings. I am going along on the test flight. The fuel lines are made of aluminium. The Present Continuous is used for: The Present Simple is used for: - actions in progress - general truths - fixed arrangements in the future - states, habits

Use the correct present tense form.

1 This a/c _______________________ (have) six fuel cells.

2 The large cells __________________ (hold) 140 gallons.

3 He _____________________ (hurry) to finish the calibration.

4 I am employed in the technical department at the moment and I

________________ (work) as a maintenance engineer.

5 I always __________________ (check) the system in accordance with the

instructions.

6 What ____________________ OA ___________________ (stand for)? It

__________________ (stand for) office automation.

7 You can't see him now. He _____________________ (work) in the hangar.

8 Gasses _________________ (expand) when heated.

9 He has already made his plans for tomorrow. He ____________________ (check)

the whole system.

10 Operators _______________ (work) a 3-shift system.

11 Look! He _________________ (try) to find out what could cause a fire in the fuel

system.

2 Expressing purpose (2)

Notice how purpose is expressed in this sentence:

He used the cross-feed system to balance the fuel load.

We can also say:

in order to balance

He used the cross-feed system for balancing the fuel system.

Now complete the following sentences using one of the patterns to express purpose.

1 Transfer pumps are used _____________________________________________.

2 Engines need lubricating oil __________________________________________.

3 Drain cocks are used ________________________________________________.

4 Fuel strainer is used ________________________________________________.

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Reading comprehension.

Read the following passage and do the tasks that follow.

Airplane Fuel System

The Jetstream 3101 is equipped with one fuel tank in each wing (see figure), and each has a

maximum usable capacity of 227 U.S. gallons. Each tank is divided into five cells (cell No. 1

is the most inboard and cell No. 5 is the most outboard) with flapper valves installed between

the cells to limit fuel sloshing. Six fuel probes are installed in each tank and are connected to

the cockpit fuel quantity gauges. A booster pump is installed in each tank to supply each

respective engine.

Downstream of each booster pump is a line-mounted, one-way check valve to prevent fuel

transfer between tanks during cross feed operations. A two-position, electrically operated

cross feed valve connects the left and right engine fuel feed lines when open. Low pressure

(LP) fuel valves are installed in each system to isolate the fuel system in the event of an

engine fire. The respective LP fuel valve closes if the associated feather lever is selected.

Each wing tank contains an independent low fuel level system that illuminates small low fuel

quantity annunciator light(s) in the cockpit if fuel levels fall below about 200 pounds in the

respective tank. The low fuel quantity annunciator lights are located on the left centre panel

between the fuel quantity gauges.

According to the Jetstream 31 Operating Manual, the low fuel quantity annunciator lights

were not designed to be warning lights. The manual states that they are a means to confirm

low fuel quantity. The airplane is also equipped with two independent fuel quantity gauges

and two fuel flow/fuel used indicators, one for each engine.

An analogue point continuously displays each engine's fuel flow rate. The indicator also has a

4-digit numerical display that shows fuel used for each engine. A small toggle switch allows

the flight crew to reset (to zero) the fuel used display. The fuel used display automatically

resets to zero when airplane power is shut off.

Write in

Slovenian terms

for fuel system

parts.

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Listening and speaking. You are going to listen to an instructor talking about fuel.

1 Before you listen, discuss what problems there might be with fuel when a

modern a/c is in flight. Which of these do you think are a problem and why?

a) Fuel is very heavy.

b) It might get too hot and start a fire.

c) The fuel tanks might leak.

d) The fuel might freeze.

e) It might move and change the balance of the a/c.

f) It smells bad.

g) The pilot might not know how much he has in the tanks.

2 Listen to the first part of the talk and see if your ideas are mentioned.

3 Look closely at the five pumps shown from a small a/c. Decide which pump:

a) is connected to a battery?

b) is just a tube?

c) has a filter before the fuel outlet?

d) has a valve to stop fuel coming back?

e) has a rotating part to push fuel through?

4 Listen to the rest of the instructor's talk. As you listen, make a list of technical

terms.

5 Listen again to the second part of the recording and complete the notes below.

pump notes

main (rotating vane) pump

transfer jet pump Tube.

Venturi principle –sucks fuel.

Transfer fuel wing tanks to collector tanks. high-pressure gear pump

delivery jet pump

electric booster pump 28 V.

Runs from battery to engine.

1 in each collector tank, fixed.

Sealed, in liquid.

Check up

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1 Answer true or false.

1 A cross-feed system is a device for mixing air and fuel.

2 A dry-wing is one which uses bladders to hold the fuel.

3 Fuel lines are tubes which carry air to the engine.

4 Sediment is foreign matter in the fuel.

5 A squawk is a measure of the quality of engine fuel.

6 Transfer pumps are used to check the quantity of fuel in a /c.

7 A fuel cap is used to select the route of fuel flow.

8 Drain cocks are used to drain off water and dirt.

9 A device for measuring the quantity of fuel is a fuel quantity probe.

10 A fuel selector is used only during an emergency.

2 Insert the missing terms from the box. There is one too many. Mind the correct word

form!

fuel caps, fuel lines, fuel strainer, sediment, single-point fuelling, bladder, boost pump, cross-

feed system, draincock, dry-wing, fuel quantity probe, fuel selector, plumbing, squawk,

transfer pumps, wet-wing.

1 An a/c could have a wet-wing instead of _________________________.

2 One of the fuel __________________ was leaking.

3 He used the ________________________ to balance the fuel load.

4 The _____________________ have to be checked.

5 ________________________ fuel systems are easy to maintain.

6 One of the ___________________ came off after take-off.

7 One of the _____________________ was cracked.

8 Did she replace a ______________________ in the left main tank?

9 She set the _________________________ to the main fuel cells.

10 They found a lot of sediments in the _________________.

11 They checked every part of the _________________ system.

12 Is the __________________________________ under the right wing?

13 The pilot had a _________________ on the fuel system.

14 They found a leak in the plumbing near a _________________________.

15 It's hard to stop leaks in a __________________________.

Make nouns and adjectives out of the following verbs.

direct ____________________________ ____________________________

transport ____________________________ ____________________________

dominate ____________________________ ____________________________

begin ____________________________ ____________________________

value ____________________________ ____________________________

function ____________________________ ____________________________

glide ____________________________ ____________________________

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3.2 ELECTRICAL SYSTEM

Role of electrical power systems

The use of electrical power to drive aircraft systems and sub-systems that had earlier been

driven by hydraulic, pneumatic, and mechanical systems is becoming a dominant trend in the

aviation industry. Advances in the areas of power electronics are providing the technology to

improve efficiency and safety of aircraft systems operation. The aircraft industry is

developing the More Electric Aircraft (MEA) with an ultimate goal of distributing only

electrical power across the airframe. The replacement of existing systems with electric

equivalents has, and will continue to significantly increase the electrical power requirement.

Can you identify the above a/c electrical parts?


M: We can start on the electrical system now. Do you have any complaints?

P: Well, I told you yesterday about the popped circuit breaker on the navigation light.

The load metres seem to be running a bit high, too.

M: There must be a short somewhere in the wiring. We’ll check the whole circuit against

the schematic.

P: What’s that instrument you’re carrying?

M: It’s a voltmeter. It’s helpful in determining the condition of the battery and generator.

Voltmeters are designed to measure either alternating current (AC) or direct current

(DC).

P: My airplane has a generator producing DC power. I know some a/c have alternators

producing either AC or DC.

M: Right. You’re a/c gets AC power from the inverter. The DC power comes straight

from the bus bar. On a/c with AC power, DC power can be created from a transformer

/ rectifier (TR) unit.

P: The auxiliary power unit (APU) has its own generator.

M: Correct. It can power the a/c electrical system without the engines running. Also, when

you start the engines, the starters use a lot of current. The APU saves your battery.

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P: All the electrical circuits are protected by circuit breakers. You don’t seem many fuses

these days, except on older a/c.

M: Very true. It’s much easier to reseat a circuit breaker than to find a fuse to replace it in

the dark.

Terminology practice.

auxiliary power unit (APU)

A small alternate power source for various systems within an a/c

The mechanic plugged in the APU before he started the engine

bus bar The junction point which distributes power from the battery to each major circuit

If the bus bar isn’t large enough, it might heat up.

fuse A device which melts when excessive current flows through it

Circuit-breakers are much more convenient than fuses.

inverter A device for changing DC to AC

Did the a/c have a spare inverter?

popped Said of a circuit breaker that is in the open (no current) position as the result of a short circuit

This circuit breaker may pop because of heavy current.

schematic A plan or drawing of the electrical system

The schematic showed that the starter was connected to the bus bur.

transformer / rectifier A device for converting AC to DC.

The Number Two TR was broken.


1 Answer these questions.

1 What is the mechanic going to check?

2 What does the pilot complain about?

3 What may be the cause of the problem?

4 What instruments does the mechanic use to measure electrical current?

5 Do all a/c alternators producing either AC or DC?

6 What does APU stand for?

7 Why can the APU power the a/c electrical system without the engines

running?

8 Why are electrical circuits protected by circuit breakers?

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2 Tick all the statements which are correct according to the dialogue.

1 The pilot complains about a short in the wiring.

2 The mechanic used two instruments for checking the electrical system.

3 There are alternators producing either AC or DC on the a/c which the mechanic is

checking.

4 The APU stands for the auxiliary power unit.

5 The APU is used to save batteries.

6 It’s easy to reset a circuit breaker.

Explanations

Can you explain what is meant by:

The left load metre read zero.

The load metre seems to be running high.

Complete this sentence:

Voltmeters are designed to __________________________________________________.

Describe briefly, in your own words if possible, the function of the APU.


1 Fill in the blanks with the following verbs. Mind the correct form!

save, use, check, replace, measure, have, come, produce

1 The APU _____________________ batteries.

2 It's difficult to ______________________ the fuse in the dark.

3 The ammeter _______________________ electrical current.

4 He will ___________ the whole circuit against the schematic.

5 The generator __________________ a short in it.

6 Power _________________ straight from the bus bar.

7 Many modern a/c __________________ alternators.

8 AC is _____________________ by an alternator.

2 Find the words which mean opposite of these:

alternating current _____________________

find _____________________

save _____________________

disconnect _____________________

stop _____________________

a circuit breaker is in open position _____________________

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Check your grammar

Past and Perfect Tenses

Past Present Perfect

The left load metre read zero. He has put new batteries in the a/c. Did the a/c have a spare inverter? The mechanic has plugged in the APU. Note that both sentences refer to These sentences refer to development a past event which is now finished which affects the present situation and and complete. are not finished or completed. The Past Simple is used for: The Present Perfect is used for: - finished past actions - unfinished past actions - no reference to present state - past to present connections

1 Insert the correct tense – Simple Past or Present Perfect.

Check-up Match the terms on the left with their definitions on the right.

1 bus bar a. a device for turning the engine to prepare it to run under

its own power

2 current b. a plan or drawing of the electrical system

3 DC c. an instrument for indicating the amount of current being

consumed

4 schematic d. the junction point which distributes power from the

battery to each major circuit

5 generator e. a device which stores electrical energy

6 inverter f. flow of electricity through a circuit

7 fuse g. direct current

8 starter h. an engine-driven device for producing electricity

9 load metre i. a device which melts when excessive current flows

through it

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3.3 HYDRAULIC SYSTEM

Hydraulic systems are becoming ever

more sophisticated with complex

assemblies of electronic, hydraulic and

mechanical components. It is vital that

these systems are cost efficient but

remain within tight performance and

safety regulations.

Systems must work correctly first time.

Such complex systems must, for both

cost and safety reasons, be ‘right first

time’, requiring engineers to have at

hand detailed and accurate information

about system performance.

Traditionally, costly physical prototyping, or ‘Iron bird testing’ was the only way to truly test

the interaction and performance of these highly complex systems at the end of the

development process. However, potential changes at this stage can be expensive and time

consuming; therefore system simulation is now used in conjunction with a ground simulation

rig to evaluate many alternatives before an optimal design is reached.

Answer these questions.

What are hydraulic systems used for? Use the illustration below to help.

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Provide Slovenian translations for the following terms:

Primary control boosters

Retraction and extension of landing gear

Shock absorption systems and valve lifting systems

Sweep back and forth of wings

Opening and closing doors and hatchways

Automatic pilot and gun turrets

Pitch changing mechanism, spoilers on flaps

Dive, landing, speed and flap brakes

Bomb bay doors and bomb displacement gears


M: Well, we go back into the plumbing business with the hydraulic system.

P: The last few minutes I’ve flown this a/c I thought I smelled hydraulic fluid, but I

haven’t seen a leak.

M: We’ll put an auxiliary hydraulic pump on the system and check it out.

P: Good. What’ll you look for?

M: For one thing, I’ll look for the leak. But I’ll also check the actuating cylinders. An O-

ring could have worn to the point of allowing a leak. I’ll check the synchronising

valve, too.

P: This is more complex than the fuel system.

M: Well, the pressures are greater – about 1,500 pounds per square inch (psi). There is an

accumulator to take out the surges.

P: The hydraulic system isn’t working all the time, is it?

M: In this system, it’s maintaining pressure all the time, even if no work is taking place.

When it’s not working, the excess hydraulic fluid is bypassed, and a pressure relief

valve keeps the pressure at the right level.

P: Where is the reservoir?

M: It’s back in the fuselage. Ah, here’s your leak. This elbow must be cracked.

P: You’ll have a hard time reaching it.

M: You’re right. Hand me the dikes, please. Thanks. I’ll cut this safety wire and put a

socket on this nut. There. We can get it now.

P: I’ll bet the O-ring on this actuator needs replacing.

M: Could be. Here, hold this with the pliers.

P: Sure.

M: Now I can get to the sequencing valves. Let’s check their gaskets.


Work in pairs. Find Slovenian translations for the words in bold print.

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1) Answer these questions.

1 What irregularities did the pilot notice on some of his latest flights?

2 In what way will the mechanic check the system?

3 What is the mechanic going to check in the hydraulic system? Make a list.

4 What is the function of the accumulator in the hydraulic system?

5 What keeps the pressure at right level if the hydraulic system is not working?

6 Where can the hydraulic fluid be found?

7 What tools did the mechanic use to repair the hydraulic plumbing?

8 What did he do?

2) In the following questions, choose the most accurate statement

according to the information given in the dialogue.

1 a) The pilot did not smell the hydraulic fluid, but he found a leak.

b) The pilot smelled the hydraulic fluid and he saw the leak.

c) The pilot smelled the hydraulic fluid but he did not find the leak.

2 a) The hydraulic system on this airplane is working all the time.

b) The hydraulic system i.e. maintaining pressure all the time on this airplane.

c) The work is taking place all the time in the hydraulic system on this airplane.

3 a) The pressure in the hydraulic system is maintained by the pressure by the

pressure relief valve.

b) The sequencing valve keeps pressure in the hydraulic system.

c) The pressure is kept by the synchronising valve in the hydraulic system.


1) Complete the table with appropriate nouns, verbs, or adjectives.

noun verb adjective

bypass

press

switch sequencing

handling

use

actuating

leak

losing

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2) Complete the sentences with the following technical terms:

pump, relief, hydraulic, valve, cylinder

1 The excess _______________________ fluid is bypassed.

2 A pressure _______________ valve keeps the pressure at the right level.

3 They checked the synchronising ___________ on the flaps.

4 The actuating ___________ is a device in the hydraulic system.

5 The hydraulic _________ has a bypass on it.

3) Notice the use of these words in the dialogue.

crack, wear, fly, surge, smell, keep, hold

Now write the appropriate word into each of the following sentences. Mind the

correct form!

1 A pressure relief valve _______________ the pressure at the right level.

2 The reservoir _____________ two gallons of hydraulic pressure.

3 The pressure _______________ suddenly to 1,200 psi.

4 On O-ring could have _________________ to the point of allowing leak.

5 The last few times I have __________________ this airplane I _____________

hydraulic fluid.

6 This elbow must be ______________________.

4) Find the words in the dialogue which can be used to replace those in bold print

below.

1 I will examine the hydraulic system.

2 I will search the leak in the plumbing.

3 There is an accumulator to release the surges.

4 A pressure relief valve maintains the pressure at the right level.

5 Now I can reach the sequencing valves.

Check your grammar.

The “going-to” future tense

If you think the event you are referring to will happen quite soon or if you are stating your

intention that it will happen, you can use the form »going to« followed by an infinitive.

Example:

There is a leak. I am going to check the hydraulic system.

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Your turn. Say what the mechanic is going to do. Choose the correct phrase from the

box.

go back into the plumbing business

put an auxiliary hydraulic pump on the system

look for the leak

check the synchronising valve

cut the safety wire

check the gaskets

examine the electrical system

replace the actuator

put the auxiliary pump on the system

Language work.

Noun + noun combinations are often used in engineering and contain a noun formed from a

verb. Often the verb indicated the function of the object described.

Example:

object: air-compressor

function: to compress air

We can express this information in a sentence:

An air-compressor is used to compress air.

Write similar sentences to indicate the function of the following objects. Note that some of the nouns end in –er and some in –or.

speed governor

mass carrier casing liner sequencing valve relief valve oil cooler pressure regulator steam condenser air heater gas generator

What are the names of the following objects?

a device used to reduce speed (of a motor) a device used to indicate the level of oil (in a gear box)

a device used to grind the surface (of a metal plate)

a device to inject fuel (into petrol or diesel engine)

a device to filter oil (for an engine)

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Work in pairs. Look at the illustration and describe the functioning of a hydraulic

system in a helicopter.

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Check up.

Match the terms on the left with their definitions on the right.

1 bypass a a device which extends or retracts

2 dikes b a storage tank 3 actuating cylinder c a momentary increase in pressure 4 psi d a circular gasket 5 reservoir e to go around 6 surge f a device which cause several actuating

cylinders to move in a particular order 7 pump g diagonal pliers 8 sequencing valve h a device used to eliminate surges 9 O-ring i a device for moving fluid 10 accumulator j pound per square inch

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3.4 LANDING GEAR

Tricycles or tail draggers?

Most medium sized and large a/c today are built with tricycle undercarriages (A). However,

there are some smaller a/c that are fitted with the more old-fashioned tail dragger (B) design.

Speaking.

Work in pairs and discuss these questions:

a) What are the main functions of an a/c undercarriage?

b) Can you think of dis/advantages of each undercarriage design?

Listening.

To which landing gear does each of these statements apply?

A B

a Forward visibility is not good b The centre of gravity is behind the front landing gear. c It's easier to land and unload the a/c. d You don't need so much skill to land and take off. e The nose wheel is easily damaged on rough and uneven ground. f The plane can spin round (or ground loop) when landing or taking off. g Because it's closer, the propeller sometimes hits the ground. h The landing gear is a lighter load for the plane to carry. i It can be damaged by very strong winds when parked on the ground. j There is more air resistance, which means lower speeds.

Listen to a discussion between two members of a flying club and check your answers.

Fit for Flight II

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Listen again to part of the conversation. Which part of the information below is

incorrect in each case?

a There's no danger of breaking your nose wheel in a hole.

b I'd much rather make an emergency landing in yours than mine.

c The centre of gravity is between the wheels.

d And the cockpit is pointing up towards the sky – you can't see a thing.

e You just have to pay close attention.

f I have done a lot of groundloops myself.


M: While I have the auxiliary hydraulic pump hooked up, I’ll run a retraction test on the

gear. I’ll get some jacks.

P: This will give you a good chance to see the whole landing gear system, won’t it?

M: Yes. I know, I’d better replace thise tyres. I can see cord through the thread. I’m afraid

you could have a blown up soon.

P: There are a lot of landings on those tyres. How do the brakes look?

M: The linings look like they might be a bit worn. The disk looks OK. These are much

better brakes than the old type with shoes and drums. We’ll also check the antiskid

system.

P: On every landing I notice the nose gear has a little shimmy.

M: OK, I’ll check it. The fork looks good. Do you see how this gear locks down? This

strut goes over-centre.

P: Right. On retraction, I guess this hook locks the gear up.

M: Yes, it does. These well doors come over the wheel after the gear is all the way up.

P: What makes them come up after the gear gets in place? Why not before?

M: They would, except for the sequencing valves. These make all the elements of the

system work at the right time.


antiskid A device which prevents wheels from locking and skidding during brake application

The left wheel’s antiskid is not working.

jack A device used for raising the a/c so that its weight is taken off its wheels

Put your jack right under this jack point.

gear A short way of saying landing gear, the apparatus used to support an a/c while in contact with the ground or surface

Do you see how this gear locks down?

shoe A curved part which is pressed against a brake drum for braking action

Not many a/c have brakes with drums and shoes.

drum A cylinder attached to the wheel, against which braking forces are applied

The drums were filled with dirt.

Fit for Flight II

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Complete the table.

term definition Slovenian

lining

over-centre

shimmy

strut

thread

well

cord


1) Answer true or false.

1 The mechanic will get some jacks to run a retraction test on the gear.

2 On running the retraction test on the gear the mechanic won’t be able to see the

entire landing gear system.

3 A blowout may cause the airplane to go off the runway.

4 The complete brakes are OK.

5 There is a minor problem with the nose gear.

6 Overheating may damage a disk.

7 The well doors come over the wheel before the gear is all the way up.

8 The synchronising valve makes all the elements of the gear system work at the

right time.

2) Try to complete these definitions using the information given in the terminology

practice.

1 A drum is _________________________________________________

2 A jack is __________________________________________________

3 Gear is a short way of saying __________________________________

4 A shoe is __________________________________________________

5 Antiskid prevents an a/c’s wheel ________________________________

Fit for Flight II

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1) Give the noun form of the following:

hooked

raise

replace

brake

causing

blow out

take off

fail

2) Say which word in the dialogue has the same meaning:

a good opportunity examine

completely retracted slightly worn

it may be in good condition

Check your grammar

Adverbial clauses of time (future reference)

When the time clause refers to the future, we normally use the simple present after:

as soon as, after, before, by the time, immediately, the moment, till, until, while, when.

Example:

While I have the auxiliary hydraulic pump hooked up, I'll run a retraction test on a gear.

Now fill in the gaps with the correct forms of the verbs in brackets.

1 When I _______________ (raise) the a/c, I'll see the whole landing gear.

2 The mechanic _______________ (check) the antiskid system after they examines

the landing gear.

3 You will find the failure the moment you __________ (remove) the inspection

plates.

4 They will complete the bench check by the time the pilot _________________

(get) on the next flight.

5 He __________________ (start) the inspection run immediately they taxi the a/c to

the hangar.

6 The will run a retraction test on the gear as soon as the senior mechanic

______________ (arrive).

Fit for Flight II

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Language work.

Noun + noun combinations (2)

Many grammatical relationships are possible in noun + noun compounds. Look at the

following examples:

a) A diesel engine = an engine which uses diesel oil

b) A brass bearing = a bearing which is made of brass

c) Carbon steel = steel which contains carbon

d) A piston engine = an engine which has pistons

1) Find further examples of each type in the following list and mark them (a,b,c,d).

heat engine

turbine engine

chromium steel

steel plate

wing nut

metal casing

electric drill

concrete bridge

aluminium alloy

2) What relationships can you see in the following list?

fuel gas

single-point fuelling fuel selector valve transfer pump needle valve instrument panel gear lubricant circuit breaker bus bar

Check up.

Insert the missing terms.

1 Most jet a/c have __________________________ systems.

2 The ___________________ caused the airplane to go off the runway.

3 The _________________ was damaged when the tyre hit a rock.

4 The __________________ shimmies because it's loose.

5 They will replace the ___________________ before we take off.

6 The landing gear collapsed because it had not gone over-centre.

7 The __________________ is mounted to the wing.

8 There's a lot of engine oil in the well.

FIT FOR FLIGHT II Lecture notes and practice MODULE 3 ...

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