Engines, APU Flashcards
What is the required engine cool down time prior to engine shutdown
3 minutes
What’s the function of the FUEL Control Levers
ON
OFF
ON - normally completes ignition circuit, then turns on fuel
OFF - shuts off fuel, then ignition
Conditions under which the ART system activates(5)
- 30% differential in N1
- Wind shear
- Selected DFCG fails
- DFGCs are manually switched
- N1 input fails
Describe the indications that fuel heat is on and what are the engine gauge value differences
MD88 only
The blue L/R FUEL HEAT ON annunciator lights on the OAP will illuminate. Fuel and oil temperature indications should also rise.
What is indicated by the amber REVERSE UNLOCK light and the blue REVERSE THRUST light
L/R REVERSE UNLOCK, Amber - illuminates when the thrust reverser is unlocked
L/R REVERSE THRUST, Blue - illuminates when thrust reverser is fully extended
What’s the meaning of the ENG SYNC ON, OAP message
BOTH
MD88
Both - illuminates when LANDING GEAR handle is in the down position and ENG SYNC selector is in N1 or on the 88, N2 also
What is the max APU start altitude, Windmill start, Operating altitude Max altitude for elect use For use of APU pneumatics MD88 MD90
MD88 - max elec start F370 Max Elect use F370 Max windmill F300 Max operating F370 Pneumatic - can't use for
MD90 - max elec start F350 Max elect use F370 No windmill start Max operating F370 Max pneumatics F200
What is the required engine warm up. Prior to take off power application
Parameters for cold soaked?
- Two minutes at idle prior to take off
- Five minutes if possible if engine has been shut down more than two hours
- 5 minutes with engine anti ice on regardless of weather conditions
What conditions will cause an AUTO ABORT during automatic start on the MD90
When is auto abort inhibited for the 90?
- Hot start
- Hung start
- Locked N1 rotor
- Ignition failure
- Electronic control lost
- Engine stall
- EGT failure
50% N2
On the MD90 is there an auto abort feature for low oil pressure or high vibration
No
When should the FUEL Control lever/ Fuel switch placed to ON during the start
MD88
MD90
MD88. - at max motoring rpm with EGT below 100*
1. Normal is 22-24% N2 2. Minimum N2 - 20%
MD90 - at max motoring rpm with EGT below 250*
1. Normal is 25-26% N2
2. Minimum N2 is 15%
3 fuel flow will not begin for 30 seconds after valve has opened
What automatically occurs with the APU pneumatics when a L/R TAIL TEMP HIGH light illuminates
APU pneumatic duct depressurizes automatically
What is the function of the fuel heat switch
MD88 only
OFF
ON
MD88 only
OFF- remove power from fuel Heat circuit following completion of fuel heat cycle
ON - (momentarily) timer is energized for one minute, which opens respective fuel heat valve, supplying high stage bleed air to the air/fuel heat exchanger
Not on MD90
Describe the engine vibration display
MD90 only
Shows vibration level from 0 to 9.9
(normal range is approximately 0.0 to 4.0)
Only MD90
What conditions would lead to MANUAL ABORTED START(assumes a manual start on the MD90)
BOTH
MD88
MD90
BOTH - no N2 rotation
- no oil pressure prior to 20% N2 - rapid EGT rise toward limit
MD88 - no N1 rotation prior to 20% N2
- no fuel flow indication or EGT rise with in 20 sec. after placing fuel lever on - Hung start(N2 fails to increase above 42% - fuel flow digits are flashing combined with one or more of the abnormal engine indications listed above
MD90 - no N1 rotation gprior to 33% N2
No EGT rise within 20 seconds after fuel flow
- Engine vibrations above 4.0