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
What’s the engine warm up procedure during cold weather operations
Failure to do so may?
MD88
MD88
- Start both engines to allow for for 5 minute warm up
- Engine anti-ice on regardless of environmental conditions
- After warm up, advance to 1.2 EPR and check for normal EPR increase
- If EPR indications are not approx. equal for both engines, warm up for 2 additional minutes
- check again, and it still abnormal, contact MCC
Failure to do so may result in bad EPR indications
What are the required engine warm up procedure during cold weather operations
MD90
- Minimum oil temperature before advancing throttle above idle is -10*C
- Oil temperature must reach 50°C before take off
In the MD90 The oil temperature readout will temporarily flash when the engine oil temperature is lower than -10°C in the throttle is moved above Idle
What happens when the ART System activates
- Thrust on the operating engine increases to maximum take off thrust, throttles do not move
- The Amber ART light is illuminated
- Maximum take off EPR is displayed in the EPR LIMIT readout on the engine display panel
What is the meaning of the OAP message ART INOP
MD88 only
- The system has failed the self test
- The ART switch is in the off position.
- The OFF position is used when accomplishing and alternate(flex power) or maximum power take off(anything other than a normal power take off)
Explain the function of theAutomatic Reserve Thrust (ART) system on the MD88 only
- The ART System provides an increase in thrust during a normal power takeoff with an engine failure or a windshear encounter
- If either condition occurs during a normal power take off the operating engine will automatically advance to MAX thrust
When is APU air available
MD88
MD90
MD88
1 after start a 60 second warm up will occur
2. During shutdown a 60sec cool down will occur
3. During the warm up and cool down periods APU bleed air is not available
MD90
No warm up needed prior to using pneumatic air
What is important to remember about the APU air switch on the MD90
When the switch is on, on the ground it will open the ram door. when opened the ram door extends even with the tail skid. Moving the switch to off will retract the ram door, thus eliminating the possibility of ram door damage in the event of a tale skid strike during take off rotation or landing flare
What’s the function of the APU AIR switch in the AIR COND COLDER position
- The turbine bypass valves close, resulting in increased differential pressure across the air conditioning turbine to provide colder air, but at a reduced volume
- Do not use this position with the engines running
What is the abnormal bleed configurations that cause a NO MODE annunciator light (Amber) on the Thrust Rating Panel (TRP)
MD88 only
AIrfoil ice protection ON and:
- one or both pneumatic cross feeds Open and engine anti-ice off
- MCT selected with both pneumatic crossfeeds open
- CL selected with one pneumatic crossfeed open
Both packs off:
1. With MCT, CL, or CR selected
Engine anti-ice ON and:
- TO or TO FLEX selected with RAT +10*C
- GA selected with RAT +14*C
What are the functions/ indications of the N1 mode on the MD90 only
Overspeed protections
Return to EPR?
- DEFAULT N1 Mode occurs when the EEC is not able to measure or control thrust using a valid EPR. –The respective N1 mode Select switch illuminated DEFAULT
- SELECTED N1
- Mode operation is obtained by either- pressing the respective N1 mode select switch,
- pushing the throttle lever’s beyond the overrated thrust gate,
- or by utilizing emergency reverse thrust. The respective N1 mode select switch illuminates SELECT
- When an engine is in N1 Mode, autothrottle can cause the EEC to control the engine and a thrust level in excess of that allowed by the maximum EPR limit. overspeed protection is provided but the EGT must be monitored to ensure that EGT limits are not exceeded
- Engine May be returned to EPR Mode by retarding throttle lever’s below the overrated thrust gate and pressing N1 mode select switch to extinguish the DEFAULT or SELECT indication
Are autothrottles available in N1 mode
MD90 only
No
What are the minimum oil quantities for dispatch at Maintenance and Non-Maintenance stations
MD88
MD90
MD88
- Non-maint. 8
- Maint. 12
MD90
- Non-maint. 12
- Maint. 16
- After engine start. 8
What’s the function of the MAN EPR SET knobs
MD88 only
- Pull knob and rotate to set desired EPR in CMD EPR Readout. EPR reference bug will move to corresponding value on EPR indicator
- When knob is pushed in CMD EPR Readout Will blank, EPR reference bug will move to EPR value set with TRP
What's the function of the ENG SYNC Selector MD88 N1 N2 OFF
MD90
OFF
N1
MD88
- N1 - left engine N1 rpm is matched to the right N1 rpm
- N2 - left engine N2 rpm is matched to the right engine N2 rpm
- OFF - EPR synchronization is available. N1 and N2 synchronization is disabled
MD90
- OFF - (EPR sync selected) The system matches the left engine EPR command to the right engine
- N1 - (N1 sync selected) The system matches the left engine N1 to the right engines
Describe the function of the ENG IGN switch 88 SYS A SYS B OFF BOTH OVRD
90
AUTO
ON
MD88
- SYS A - selects igniter A with the fuel control lever on
- SYS B - selects igniter B with fuel control lever on
- OFF - remove power from all igniters
- BOTH - provides power to all igniters with fuel control lever on
- OVRD - provides power to igniters in both engines, bypassing fuel control levers
MD90
- AUTO - ( normal) (auto abort available)ignition controlled by the EEC.
- AUTO position automatically alternates between the A and B Systems for normal engine starts…
- or provides dual ignition for take off, approach, engine anti-ice on, sub idle (N2) conditions, Engine surge and throttle past frangible gate - ON - (auto abort not available)EEC continuously Powers both igniters
What’s the operation of normal/emergency reverse thrust on the MD90
- It’s equipped with cascade type reverses
- Activation of reverse thrust above 60 kn provides a maximum of 1.30 EPR
- Activation of reverse thrust below 60 kn provides a maximum of 1.07 EPR
- If initiated above 60 kn, pulling the reverse thrust levers past the overrated thrust(ORT) Gate activates emergency reverse thrust and increases reverse thrust an additional 10%
What happens in the MD90 if emergency reverse thrust is used
1 generates an ENGINE STSTEM FAIL message on OAP
2. Necessitates an engine inspection prior to subsequent operation
What’s the function of the FUEL control levers
88 only
ON
OFF
- ON - allows EEC to open fuel valve at fuel metering unit( fuel will not flow for 30 sec after start valve has opened)
- OFF - EEC closes fuel valve
Test function of the THRUST RATING PANEL (TRP)
88 only
Push button to test 1. RAT 12* +/-1 2. EPR LIMIT. 2.08 +/-.01 3. All lights on panel should be extinguished. When button is released 1. Ambient temp in RAT Readout 2. EPR will display dashes 3. NO MODE Light should illuminate
What’s the function of the NO MODE annunciator light (Amber) on the Thrust Rating Panel (TRP)
Indicates one of the following conditions
- No selection made since initial power up or power interruption
- An abnormal engine bleed configuration exists for the mode selected
MD88 only
- No selection made since TRP was tested
- T.O. Flex selected and ART switched ON
