7. Engines, APU

Question 1

The airplane is powered by two _________________________ engines. The engines are rated at _______ pounds (BET - Boeing Equivelant Thrust) of takeoff thrust each.

Answer 1

The airplane is powered by two General Electric GEnx-1B76A engines. The engines are rated at 76,100 pounds (BET - Boeing Equivelant Thrust) of takeoff thrust each.

Question 2

Thrust Asymmetry Protection (TAP)

TAP is an automatic feature that provides protection against asymmetric thrust during takeoff or go-around by limiting thrust on the higher thrust engine.
TAP enhances safety by:

Answer 2

• allowing a decrease in approach speed at light gross weights, and
• providing engine-out control capability for speeds above stick shaker,
  and
• allowing full rated thrust to be available for all-engine operation at all weights and airspeeds

Question 3

Thrust Asymmetry Protection (TAP)

The TAP function does not affect thrust for engine out operations flown at or above ________, with the exception of a light weight go-around at weights less than _______ kilograms where TAP reduces thrust slightly at VREF on the go-around.

Answer 3

The TAP function does not affect thrust for engine out operations flown at or above V2/VREF, with the exception of a light weight go-around at weights less than 152,273 kilograms where TAP reduces thrust slightly at VREF on the go-around.

Question 4

Transient Bleed System

The purpose of the transient bleed system is to unload the compressor during engine acceleration for increased engine stall margin.

If the TBV remains open when commanded to close by the EEC, the EICAS advisory message ENG TBV OPEN (L or R) is displayed when the airplane is on the ground and below __ KCAS.

Answer 4

If the TBV remains open when commanded to close by the EEC, the EICAS advisory message ENG TBV OPEN (L or R) is displayed when the airplane is on the ground and below 80 KCAS.

Question 5

EEC Idle Selection

Approach idle is selected in flight when:
- the flaps are commanded to __ or greater, or
- the landing gear is selected ____

Approach idle decreases engine acceleration time for go–around. Approach idle is maintained until ______________ when the EEC selects minimum idle.

Icing idle is selected when:
- ___________________

Answer 5

Approach idle is selected in flight when:
- the flaps are commanded to 25 or greater, or
- the landing gear is selected DOWN

Approach idle decreases engine acceleration time for go–around. Approach idle is maintained until after touchdown when the EEC selects minimum idle.

Icing idle is selected when:
- engine anti-ice on

Question 6

Ice Crystal Anti-Ice (ICA) Function

The ICA function activates only above ______ ft.

The ICA function activates for at least __ minutes and may continue in additional __ minute increments, for as long as ICI conditions are encountered.

If the airplane descends below ______ ft the ICA function terminates.

__, __ and ___ may fluctuate independently without any flight crew inputs. This is considered normal behavior.

An ICA indication does not mean that the engine is currently encountering ICI conditions. After engine maintenance activities, for example after an engine change or an EEC change, the ICA indication can show in cruise flight, in any weather conditions, for 75 minutes or more.

Answer 6

The ICA function activates only above 30,000 ft.

The ICA function activates for at least 30 minutes and may continue in additional 15 minute increments, for as long as ICI conditions are encountered.

If the airplane descends below 28,500 feet the ICA function terminates.

N1, N2, and EGT may fluctuate independently without any flight crew inputs. This is considered normal behavior.

An ICA indication does not mean that the engine is currently encountering ICI conditions. After engine maintenance activities, for example after an engine change or an EEC change, the ICA indication can show in cruise flight, in any weather conditions, for 75 minutes or more.

Question 7

Engine Start and Ignition System

Two power sources that can
provide starter power; the ___ and the ______ external power.

Answer 7

Two power sources that can
provide starter power; the APU and the forward external power.

Question 8

Autostart

During ground starts, the autostart system monitors engine parameters and aborts
the start for any of the following:
- loss of _______
- no __ rotation
- no ________ rise
If one of the above conditions is detected, the EEC aborts the autostart sequence without motoring and does not make another attempt.

There is a limit of _ start attempts per start sequence while on the ground.

Answer 8

During ground starts, the autostart system monitors engine parameters and aborts
the start for any of the following:
- loss of both starters
- no N1 rotation
- no oil pressure rise
If one of the above conditions is detected, the EEC aborts the autostart sequence without motoring and does not make another attempt.

There is a limit of 3 start attempts per start sequence while on the ground.

Question 9

Engine Ignition

Airplane supplied __ power is the normal power source for ignition.

Answer 9

Airplane supplied DC power is the normal power source for ignition.

Question 10

Auto-Relight

The auto-relight function is activated on the ground and in-flight whenever an engine is at or below ___ with the FUEL CONTROL switch in ___.

Answer 10

The auto-relight function is activated on the ground and in-flight whenever an engine is at or below idle with the FUEL CONTROL switch in RUN.

Question 11

Engine Fuel System

Fuel flow is measured after passing through the _________ valve.

Answer 11

Fuel flow is measured after passing through the engine fuel valve.

Question 12

Engine Fuel System Schematic

Answer 12

Question 13

Engine Oil System Schematic

Answer 13

Question 14

Thrust Reverser System

When the reverse thrust levers are pulled aft to the interlock position:
- the _____________ disengages
- the ___________________ deploy

Answer 14

When the reverse thrust levers are pulled aft to the interlock position:
- the autothrottle disengages
- the auto speedbrakes deploy

Question 15

Thrust Reverser System

When the reverser system is activated:
- the reverser translating sleeves hydraulically move aft
- the fan flow blocker doors rotate into place to direct fan air through
stationary cascade guide vanes
- the reverser indication REV is displayed in amber above each digital N1 indication (REV is displayed in amber when the reverser is in transit)

When the interlock releases:
- the reverse thrust levers can be raised to the _______ reverse thrust position
- the REV indication changes to ______ when the reverser is fully deployed

Answer 15

When the reverser system is activated:
- the reverser translating sleeves hydraulically move aft
- the fan flow blocker doors rotate into place to direct fan air through
stationary cascade guide vanes
- the reverser indication REV is displayed in amber above each digital N1 indication (REV is displayed in amber when the reverser is in _____)

When the interlock releases:
- the reverse thrust levers can be raised to the maximum reverse thrust position
- the REV indication changes to green when the reverser is fully deployed

Question 16

Thrust Reverser System

The EICAS advisory message _________ (L or R) is displayed on the ground to indicate a reverser system fault.

The EICAS caution message ______________ is displayed when the air/ground logic that prevents in-flight thrust reverser deployment has failed.

The EICAS caution message ____________________ (L or R) is displayed when the left or right reverse thrust lever is not in the down position in flight.

Answer 16

The EICAS advisory message ENG REVERSER (L or R) is displayed on the ground to indicate a reverser system fault.

The EICAS caution message ENG REV AIR/GND is displayed when the air/ground logic that prevents in-flight thrust reverser deployment has failed.

The EICAS caution message ENG REV COMMANDED (L or R) is displayed when the left or right reverse thrust lever is not in the down position in flight.

Question 17

Thrust Reverser Schematic

Answer 17

Question 18

Airborne Vibration Monitoring System

If the vibration monitoring system cannot determine the source, ____________ is displayed for the affected engine.
_________ vibration is the ________ vibration detected.

What is the certified vibration limit?

Answer 18

If the vibration monitoring system cannot determine the source, BB (broadband) is displayed for the affected engine.
Broadband vibration is the average vibration detected.

There is no certified vibration limit.

Question 19

Engine Failure Alert System

A red ENG FAIL is displayed on both PFDs, and ENG FAIL is displayed on both HUDs if actual thrust is less than commanded thrust during takeoff with airspeed between __ knots and _ knots prior to V1.

The EICAS caution message ENG FAIL (L or R) is displayed if an engine unexpectedly decelerates to ____________ speed.

Answer 19

A red ENG FAIL is displayed on both PFDs, and ENG FAIL is displayed on both HUDs if actual thrust is less than commanded thrust during takeoff with airspeed between 65 knots and 6 knots prior to V1.

The EICAS caution message ENG FAIL (L or R) is displayed if an engine unexpectedly decelerates to less than idle speed.

Question 20

Engine Failure Alert System

The EICAS caution message ENG THRUST (L or R) is displayed if:
- the engine is producing ____ than commanded thrust, and actual thrust is not satisfactorily _______ towards the commanded thrust, or;
- the engine is producing ____ than commanded thrust, and actual thrust is not satisfactorily __________ towards the commanded thrust
- and, the current airspeed is greater than _ knots prior to V1

Answer 20

The EICAS caution message ENG THRUST (L or R) is displayed if:
- the engine is producing less than commanded thrust, and actual thrust is not satisfactorily increasing towards the commanded thrust, or;
- the engine is producing more than commanded thrust, and actual thrust is not satisfactorily decreasing towards the commanded thrust
- and, the current airspeed is greater than 6 knots prior to V1

Question 21

APU Start

The APU battery is designed to support two consecutive start attempts. If the APU fails to start after the second attempt, a _ minute cooling period must be observed before a third attempt is made.

Answer 21

The APU battery is designed to support two consecutive start attempts. If the APU fails to start after the second attempt, a 5 minute cooling period must be observed before a third attempt is made.

Question 22

APU Automatic Start

If _____ or more engine generators go offline, the APU automatically starts, regardless of APU selector position.
When the automatic start condition is no longer valid, the APU can be shut down by positioning the selector to __, then ___.
When the automatic start condition is valid, the APU can only be shut down by ________________.

Answer 22

If three or more engine generators go offline, the APU automatically
starts, regardless of APU selector position.
When the automatic start condition is no longer valid, the APU can be shut down by positioning the selector to ON, then OFF.
When the automatic start condition is valid, the APU can only be shut down by pulling the APU fire switch.

Question 23

APU Shutdown

At any time during the cooldown period, the APU may be returned to its running condition by placing the APU selector back to __.

Answer 23

At any time during the cooldown period, the APU may be returned to its running condition by placing the APU selector back to ON.