Engines, APU Flashcards
(ALL) Identify the conditions that would lead to an aborted engine start
and accomplishment of the Aborted Engine Start checklist.
Oil pressure rise does not occur.
Fuel flow is abnormally high or fluctuating.
EGT does not increase by 20 seconds after the FUEL CONTROL switch is positioned to RUN.
N1 fails to increase after EGT rise
EGT quickly nears or exceeds the start limit.
Oil pressure indication is not normal by the time the engine is stabilized at idle
(ALL) Recall the required engine warm up period prior to the application
of T/O thrust.
Required warm up time is 3 minutes.
Target warm up time is 5 minutes.
Note: Do not delay takeoff after 3 minute warm-up period.
3 (ALL) Recall the engine cool down recommendations prior to engine shutdown.
Run the engine for at least 3 minutes.
Shutdown may be accomplished earlier for gate arrival
(756) Describe when the FUEL CONTROL switch should be placed
to RUN during an engine start.
Verify oil pressure increase and N2 rotation
When N2 is at 25%, or if 25% N2 is not possible at maximum motoring speed, attempt the start at a minimum of 18% N2 (757)
or 15% N2 (767).
NOTE: A magenta bug (fuel on command bug) appears at:
18% N2 on the 757
15% N2 on th e767
(756) Recall the APU starter duty cycle.
The starter duty cycle is a maximum of 3 consecutive starts or attempts within a 60 minute period.
(756) Recall the maximum altitude to use APU Electrics.
Electrical power is available throughout the entire airplane operating envelope
(756) Recall the maximum altitude to use APU Pneumatics.
In flight, APU bleed air is available up to approximately 17,000
feet
What protections do the EEC’s provide
- Overboost
- N1 and N2 overspeed protection
Note: No EGT over temperature protection provided
(756) Recall the primary indication for setting thrust on PW engines.
EPR
Recall the primary indication for setting thrust on GE engines.
N1
(756) Explain how to cancel the APU shutdown sequence if OFF is selected and the RUN light is still illuminated.
Momentarily move the APU selector to the START position.
(756) Recall the meaning of an illuminated APU RUN light.
The APU is at operating speed
(756) Recall the meaning of an illuminated APU FAULT light.
Illuminated (amber):
- The APU has automatically shut down.
- The APU fuel valve disagrees with the commanded position.
- A fault is sensed.
Note: The FAULT light momentarily illuminates during an APU start
because the APU fuel valve initially disagrees with the commanded position.
(756) Recall the engine starter duty cycle.
Continuous for 5 minutes
Cool for 30 seconds per minute of operation
(756) Recall the meaning of an illuminated L or R ENG OIL PRESS light.
The respective oil pressure is at or below the minimum value.
The oil pressure switch has malfunctioned.