ENGINES,APU

Question 1

Which system regulates the engine?

Answer 1

A dual-channel Electronic Engine Control (EEC) regulates each engine. The EEC monitors autothrottle and Flight Crew inputs to automatically set engine thrust.

Question 2

What is the indication an EEC is operating in normal mode?

Answer 2

In normal mode, white ON lights are the only lights illuminated on the associated EEC switch on the engine panel.

Question 3

What are the indications of EEC hard alternate and soft alternate modes?

Answer 3

In soft alternate mode, the ALTN switch illuminates and the ON indication remains visible.

If hard alternate mode is entered by reducing the thrust lever to idle while in soft alternate mode, the ALTN switch remains illuminated and the ON indication remains visible. When ALTN is selected manually, the ON indication is blanked.

Question 4

The EECs provide redline overspeed protection for which engine parameters(s)?

Answer 4

The EECs provide N 1 and N 2 redline overspeed protection in both normal and alternate modes.

Question 5

When do the EECs select approach idle for the operating engine?

Answer 5

Approach idle is selected:

• with Flaps 15 or greater, or
• any time the flaps are not fully retracted and engine anti-ice is on

In flight, if a fault prevents the EEC from receiving flap or anti-ice signals, approach idle schedule begins below 19,000 ft MSL.

Question 6

What does the ENGINE CONTROL light indicate and when is it armed?

Answer 6

A non-dispatchable fault in the EEC will illuminate the ENGINE CONTROL light.

Armed when:

• the respective engine is operating, and
• the aircraft is on the ground, and
• below 80 kts prior to takeoff, or 30 seconds after touchdown

Question 7

When is the ENG FAIL alert displayed?

Answer 7

An ENG FAIL alert is displayed on the EGT indicator when the respective engine is operating at a condition below sustainable idle and the engine start lever is in the IDLE position. The alert remains until:

• the engine recovers,
• the engine start lever is moved to CUTOFF, or
• the fire switch is pulled

Question 8

How are the secondary engine instruments toggled?

Answer 8

Secondary engine indications are displayed when ENG is selected on the Multi-Function Display panel.

Question 9

How are EGT redline exceedances indicated?

Answer 9

If EGT indications exceed the redline, the digit readout, box, needle, and indicator change color to red.

Question 10

How is an EGT exceedance displayed after engine shutdown?

Answer 10

On the ground, after engine shutdown, a box the color of the exceedance (red or amber) displays around the digital readout where the exceedance occurred.

Question 11

How is the N1/SPD REF SET page displayed on the Max Display System?

Answer 11

The N1/SPD REF SET display is populated by selecting INFO on the MFD panel on the forward electronic panel.

Question 12

What does the THRUST crew alert on the Engine Display indicate?

Answer 12

When the thrust is more or less than the commanded thrust.

Question 13

What are the indications of reverse thrust on the Engine Display?

Answer 13

REV (amber) indicates the associated thrust reverser is moved from stowed position.
REV (green) indicates the thrust reverser is deployed.

Question 14

What does selecting FUEL USED display?

Answer 14

Selecting USED will display fuel used since the last reset for 10 seconds.

Question 15

What does the illumination of the FUEL FLOW crew alert indicate?

Answer 15

Illumination of FUEL FLOW indicates fuel flow is abnormally high when compared to the FMC expected fuel flow.

Question 16

What does the illumination of the OIL FILTER BYPASS light indicate?

Answer 16

Illumination of OIL FILTER BYPASS indicates the impending bypass of oil supply filter.

Question 17

Which engine start ignitor is available on standby power?

Answer 17

The right igniter plug receives power from the AC standby bus.

Question 18

The auto-relight function of the Engine Start System is available when the engine start switches are in which position(s)?

Answer 18

An auto-relight capability is provided for flameout protection when the start switch is in any position.

Question 19

What does MOTORING on the N2 indicator indicate?

Answer 19

Bowed Rotor Motoring straightens the N1 and N2 rotor shafts which will bow due to thermal buildup after the engine is shut down. BRM is active for 6–90 seconds on the ground only. During BRM, MOTORING is displayed on the N2 gauge between 18% and 24% N2.

Question 20

Which start malfunction(s) do the EECs monitor for during engine start?

Answer 20

EEC monitors engine parameters to detect impending hot starts, engine stalls, EGT start limit exceedances, and wet starts. (Ground only).

Question 21

How is an impending hot start indicated during engine starting?

Answer 21

A rapid rise in EGT or EGT approaching the start limit, the white box surrounding the EGT digital readout flashes white.

Question 22

What does the illumination of the REVERSER LIMITED light indicate?

Answer 22

Illuminates in flight when a fault in the thrust reverser system limits reverser thrust. The thrust reverser will not deploy or reverse thrust will be limited to idle if commanded. The REVERSER LIMITED light illuminates on the ground when a malfunction has occurred.

Question 23

What does the illumination of the REVERSER COMMAND light indicate?

Answer 23

The illumination of the REVERSER COMMAND light indicates the reverse thrust lever is not in the down position in flight.

Question 24

What does the APU provide?

Answer 24

The APU supplies bleed air for engine starting or air conditioning.

An AC electrical generator on the APU provides an auxiliary AC power source.

Question 25

Does the APU require the BAT switch to be on to operate?

Answer 25

APU operation requires the BAT switch to be ON.

Question 26

How long should the APU run after illumination of the APU GEN OFF BUS light before opening the APU bleed valve?

Answer 26

Operate the APU for two full minutes before using it as a bleed air source. This two-minute stabilization is recommended to extend the service life of the APU.

Question 27

How long should a pilot wait after the APU switch is selected OFF before selecting the BAT switch OFF?

Answer 27

Wait at least three minutes after APU GEN OFF BUS light extinguishes before positioning the BAT switch to OFF to allow adequate time for the APU inlet door to fully close.

Question 28

What will cause the automatic shutdown of the APU?

Answer 28

• RPM overspeed conditions
• low oil pressure
• high oil temperature
• APU fire
• Fuel Control Unit failure
• EGT exceedance, and
• other system faults monitored by the ECU