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Flashcards in Engine Deck (39):
0

What type of engines

General Electric


Cf34- 8E5
High bypass dual rotor turbofan

1

What controls engines

Dual channel FADEC system

2

Describe how fuel gets to engines

From collector tanks to engine fuel pumps. Splits into 2 streams

High pressure pump back to tanks to supply motive flow

Low pressure pump to heat exchanger to fuel filter, back to high pressure pump then to FMU (fuel metering unit) then to fuel imjectors

3

Oil system lubricates and cools what ?

Turbine engine main shaft bearings and accessory gear box

4

Where is oil quantity info displayed

MFD

5

What does the starter system include

ATS ( air turbine starter)
SCV ( starter control valve) controlled by FADEC

6

Describe start sequence on ground

FADEC opens SCV to allow pneumatic system to provide air to the ATS. FADEC initiates ignition at 7% N2 and fuel flow starts at 20% n2 provided ITT is 120° c or less

After lightoff , starter cutout at 50%n2 and commands FMU TO accelerate to ground idle

7

Ignition system


How many systems for start are energized

Ground?

Flight?

1 on ground

2 in flight

8

What does ignition override do

Both igniters on each engine are energized

Will cause sig reduction in igniter life if used frequently

9

Describe in flight cross bleed start

Identical to ground start except FMU opens to provide fuel after 15 seconds even if 20% n2 is not reached

10

Describe windmilling start

Commanded by start stop switch
Ignition at 7 % n2
Fuel flow at 7.2% N2 or 15 seconds whichever occurs first

11

Does FADEC provide protection for hot starts/ hung or failure to light off

On ground yes. If no lightoff in 15 seconds after fuel flow it switches ignitions



In flight- no

12

When do you abort start

If no lightoff within 30 sec of fuel flow

13

Describe auto relight

FADEC monitors n2 and turns on both igniters and schedules relight fuel flow in event if flameout

WML icon will show next to respective engine n2 on EICAS

14

Inflight If engine does not relight automatically within 30 sec or n2 falls below 7.2% you should-

Consider it a failed attempt and you should terminate it manually by moving start stop switch to stop position

15

Auto relight on ground is terminated and fuel flow is shutoff if

N2 falls below 52%.

16

Thrust reversers are ---- actuated

And controlled via

Hydraulically

Thrust lever

17

What prevents inadvertent thrust reverser deployment and stowing

An interlock controlled by FADEC
Consisting of 2 actuator locks and an independent cowl lock

18

What is the purpose of the cowl lock

Prevents inadvertent thrust reverser deployment

19

Describe thrust reverser deployment

On ground move thrust levers to idle rev thrust
Once both cowls are deployed you can command Max rev thrust by holding thrust levers in Max rev

20

What happens if one reverser fails while in Max rev?

Operating reverser will provide only min rev thrust unless you select just the operating thrust lever to Max rev

21

If thrust reverser actuates in flight what happens

Engine thrust is limited to idle thrust

22

Engine control system consists of

FADEC
Thrust levers
T2
N1 sensors

23

What does thrust lever do

Receives input of desired thrust setting from pilot or auto throttles

24

What does T2 do

Monitors engine inlet air temp for FADEC control calculations

25

What does n1 sensor do

Provides fan speed info for FADEC and airplane vibration monitoring system

26

Describe FADEC

Main component of engine system
It provides
Engine protection
Control of requested and Max N1
Control of ATTCS

FADEC has 2 identical independent channels one is the in control
Channel the other is always in standby in case of active channel failure

The channels switch control on every start

27

Where does FADEC get it's electrical power

Below 50% n2 from the airplanes electrical system

Above 50% n2 from the PMA ( permanent magnet alternator)

28

Describe the ATTCS

Automatic takeoff thrust control system,
Controlled by FADEC and is available on t/o and go around

It will provide RSV Power in event of engine failure

Displayed on EICAS as white - armed

And green - engaged. ( only when thrust levers are in TOGA

29

When will RSV POWER BE ACTIVATED

ATTCS must be engaged
And if one of the following occurs

N1 difference greater than 15%
One engine fails during takeoff
One engine fails during go around
Windshear detected

Max thrust commanded by thrust levers

30

What is minimum flex thrust for takeoff

75% of Max rated takeoff thrust or
Climb -2 + .5 %n1 whichever is higher

31

What does
TO-x mean

Thrust used for normal takeoff

32

What are the different idle modes

Flight idle
Approach idle
Final approach idle
Ground idle

33

When is approach idle activated

Alt less than 15000'
In flight
Flaps 1 or greater
Gear down

34

When is final approach idle active

Alt lower than 1200 agl
Landing flaps set
Gear down

35

Describe n2 over speed protection

Whenever n2 reaches 102% FADEC commands an engine shutdown
In the event of 3 consecutive over speed indications within 30 sec FADEC will not relight the engine

36

If FADEC aborts the start due to a high ITT what do you need to do

Close the SCV by putting the start stop switch to stop

37

How much oil does each engine hold

10.5 quarts

7.2 usable

38

How much oil does APU hold

4.54 quarts