07 - 757 APU

The APU can be started inflight and operate up to the airplane maximum certified altitude of: 42.000ft. 43.000ft. 39.000ft.

APU operation: Electrical Power: Max Op Alt, 42.000ft. FL350. 20,000 ft. 17,000 ft. 14,000 ft.

APU operation: Start Assured: Max Op Alt, 42.000ft. FL350. 20,000 ft. 17,000 ft. 14,000 ft.

APU operation: Pneumatic System (single pack operation): Max Op Alt, 42.000ft. FL350. 20,000 ft. 17,000 ft. 14,000 ft.

APU operation: Pneumatic System (2 Pack operation): Max Op Alt, 42.000ft. FL350. 20,000 ft. 17,000 ft. 14,000 ft.

APU operation: In-Flight Crossbleed Engine Start: Max Op Alt, 42.000ft. FL350. 20,000 ft. 17,000 ft. 14,000 ft.

APU START APU start requires: both the APU BATTERY and the aircraft MAIN BATTERY. the APU BATTERY. the aircraft MAIN BATTERY.

APU START Immediately thereafter the [FAULT] light comes on and goes off as an indication that: the fuel valve opened. a self-test of the control circuitry. the inlet door opened.

APU SHUTDOWN If the APU is supplying pneumatic power, rotating the APU selector to OFF: begins the shutdown cycle by closing the APU bleed air valve. the APU fuel valve and inlet door close and the APU shuts down without delay.

APU SHUTDOWN If the APU bleed valve has been closed for a sufficient length of time when the selector is moved to OFF: begins the shutdown cycle by closing the APU bleed air valve. the APU fuel valve and inlet door close and the APU shuts down without delay.

APU SHUTDOWN If the selector is inadvertently moved to OFF, but the RUN light is still illuminated: momentarily moving the selector to START cancels the shutdown signal. the APU fuel valve and inlet door close and the APU shuts down without delay.

APU START The APU starter duty cycle is a maximum of: three consecutive starts within a 60-minute period. three consecutive starts within a 30-minute period. three consecutive starts within a 90-minute period.

APU SHUTDOWN To protect the unit from thermal shock, the APU control system incorporates a time-delay feature permitting APU cooling before shutdown. The time-delay is variable from: 0 to 120 seconds, but is nominally set at 60 seconds. 0 to 30 seconds, but is nominally set at 90 seconds. 60 to 120 seconds, but is nominally set at 90 seconds.

APU START During APU start the [RUN] light flashes twice when the APU. fuel valve opened. control unit self-test is complete. inlet door opened.

APU START During APU start, the _______ light will illuminate whilst the APU fuel valve is in transit and the _______ light flashes twice when the APU control unit self-test is complete. [FAULT] / [RUN]. [RUN] / [FAULT]. [FAULT] / [ON].

2 - APU [FAULT] Light - Illuminated (amber): • the APU has automatically shut down. • the APU fuel valve disagrees with the commanded position. • the APU has automatically shut down. • APU is at operating speed. • the APU fuel valve disagrees with the commanded position.

APU Services Electrical Power -. Max Op Alt (42.000ft). FL350. 20,000 ft.

APU Services APU Start Assured -. Max Op Alt (42.000ft). FL350. 20,000 ft.

APU Services Pneumatic System WITH single pack operation: 20,000 ft. 17,000 ft. 14,000 ft.

APU Services Pneumatic System WITH 2 Pack operation: 17,000 ft. 20,000 ft. 14,000 ft.

APU Services In-Flight Crossbleed Engine Start: 17,000 ft. 20,000 ft. 14,000 ft.

APU START When AC power is available,. the left forward AC fuel pump is signaled to operate regardless of its switch position. the right forward AC fuel pump is signaled to operate regardless of its switch position. need to switch on left aft feul pump.