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Flashcards in Engine Deck (39)
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0
Q

What controls engines

A

Dual channel FADEC system

1
Q

What type of engines

A

General Electric

Cf34- 8E5
High bypass dual rotor turbofan

2
Q

Describe how fuel gets to engines

A

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
Q

Oil system lubricates and cools what ?

A

Turbine engine main shaft bearings and accessory gear box

4
Q

Where is oil quantity info displayed

A

MFD

5
Q

What does the starter system include

A

ATS ( air turbine starter)

SCV ( starter control valve) controlled by FADEC

6
Q

Describe start sequence on ground

A

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
Q

Ignition system

How many systems for start are energized

Ground?

Flight?

A

1 on ground

2 in flight

8
Q

What does ignition override do

A

Both igniters on each engine are energized

Will cause sig reduction in igniter life if used frequently

9
Q

Describe in flight cross bleed start

A

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

10
Q

Describe windmilling start

A

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

11
Q

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

A

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

In flight- no

12
Q

When do you abort start

A

If no lightoff within 30 sec of fuel flow

13
Q

Describe auto relight

A

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
Q

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

A

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

15
Q

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

A

N2 falls below 52%.

16
Q

Thrust reversers are —- actuated

And controlled via

A

Hydraulically

Thrust lever

17
Q

What prevents inadvertent thrust reverser deployment and stowing

A

An interlock controlled by FADEC

Consisting of 2 actuator locks and an independent cowl lock

18
Q

What is the purpose of the cowl lock

A

Prevents inadvertent thrust reverser deployment

19
Q

Describe thrust reverser deployment

A

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
Q

What happens if one reverser fails while in Max rev?

A

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

21
Q

If thrust reverser actuates in flight what happens

A

Engine thrust is limited to idle thrust

22
Q

Engine control system consists of

A

FADEC
Thrust levers
T2
N1 sensors

23
Q

What does thrust lever do

A

Receives input of desired thrust setting from pilot or auto throttles

24
Q

What does T2 do

A

Monitors engine inlet air temp for FADEC control calculations

25
Q

What does n1 sensor do

A

Provides fan speed info for FADEC and airplane vibration monitoring system

26
Q

Describe FADEC

A
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
Q

Where does FADEC get it’s electrical power

A

Below 50% n2 from the airplanes electrical system

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

28
Q

Describe the ATTCS

A

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
Q

When will RSV POWER BE ACTIVATED

A

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
Q

What is minimum flex thrust for takeoff

A

75% of Max rated takeoff thrust or

Climb -2 + .5 %n1 whichever is higher

31
Q

What does

TO-x mean

A

Thrust used for normal takeoff

32
Q

What are the different idle modes

A

Flight idle
Approach idle
Final approach idle
Ground idle

33
Q

When is approach idle activated

A

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

34
Q

When is final approach idle active

A

Alt lower than 1200 agl
Landing flaps set
Gear down

35
Q

Describe n2 over speed protection

A

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
Q

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

A

Close the SCV by putting the start stop switch to stop

37
Q

How much oil does each engine hold

A
  1. 5 quarts

7. 2 usable

38
Q

How much oil does APU hold

A

4.54 quarts