AFI 11-2C-130v3 - BITS

180 AFI11-2C-130V3 23 APRIL 2012
12.10.3.13.1. A failed oil pressure switch can be detected during the start cycle by
observing no ignition firing noise during start attempt and that fuel is present at the
fuel pressure regulator drain and no detectable fuel in the nozzle hose. (See Figure
12.3)
12.10.3.13.2. Remove oil line to the oil pressure switch and momentarily rotate GTC.
(Oil should spurt from the line opening.)
12.10.3.13.3. Remove oil pressure switch cannon plug and place jumper wires from
pin ―A‖ to pin ―B‖ for ignition and from pin ―C‖ to ―D‖ for fuel. Secure the jumper
wires with tape.
12.10.3.13.4. Attempt to start the GTC. If the oil pressure switch was faulty the start
should be successful.
12.10.3.14. APU Door Fails to Actuate
12.10.3.14.1. Remove power from aircraft.
12.10.3.14.2. Remove APU compartment access panel and unsnap the APU heat
shield blanket in the upper compartment, or remove the APU door actuator panel
located aft of the APU door.
12.10.3.14.3. Remove the actuator cannon plug and install it on the APU (failed
actuator) start receptacle. (See Figure 12.7)
12.10.3.14.4. If actuator is failed in the closed position, remove the actuator mount
bolt from the fuselage and reposition the actuator to the INOP actuator position. (See
NOTE 1, Figure 12.7) NOTE: This will position the door to 35 degrees open for
engine start only. It must be positioned to the closed position prior to flight.
12.10.3.14.5. If the actuator is failed in an intermediate position, install the dummy
actuator rod. NOTE: This will position the door to 15 degrees open for engine start.
12.10.3.14.6. Reinstall the heat shield blanket and secure the panel. CAUTION:
During hot weather conditions, delay operation of the APU until immediately prior to
engine start; then operate the APU only long enough to start one engine.
CAUTION: APU operation in-flight with the door in the fixed flight position is not
recommended since the door is part of the in-flight fire protection and provides fire
containment within the fire proof area.
12.10.3.15. *APU Fails to Rotate (Start Light Fails to Illuminate)
12.10.3.15.1. Check the following items:
12.10.3.15.1.1. APU control circuit breaker-IN.
12.10.3.15.1.2. APU fire handle-IN.
12.10.3.15.1.3. Isolated bus for available power.
12.10.3.15.2. If the above items are checked and in the normal operating
configuration, the Auto Start Relay (ASR, upper relay) on the APU is inoperative (see
Figure 12.6). Swap the ASR and the Fuel Holding Relay (FHR, lower relay) and
attempt another start.