Engines / APU

Question 0

(88, 90) Meaning of “ENG SYNC ON” OAP message:

Answer 0

• Illuminates when LANDING GEAR handle is in the DOWN position and ENG SYNC selector is in N1 (88 and 90) or N2 (88 only) position.

Question 1

(88) Indications that fuel heat is on:

Answer 1

• Blue L/R FUEL HEAT ON annunciator light(s) on OAP will illuminate. Fuel and oil temp. indications should also rise.

Question 2

(88, 90) Explain what is indicated by the amber REVERSE UNLOCK light and the blue REVERSE THRUST light:

Answer 2

• L/R REVERSE UNLOCK Light (amber) - Illuminates when thrust reverser is unlocked.
• L/R REVERSE THRUST Light (blue) - Illuminates when thrust reverser is fully extended.

Question 4

(88, 90) MD-90 engine warm up procedure during cold weather operations.

Answer 4

MD-90
• Min. oil temp before advancing throttle > idle is -10°C.
• Oil temp. must reach 50°C before takeoff.

NOTE (MD-90): Oil temp readout will momentarily flash when engine oil temperature < -10°C and throttle is moved above idle.

Question 5

(88, 90) MD-88 engine warm up procedure during cold weather operations.

Answer 5

MD-88 - For 1st flight of the day w/ OAT ≤ -6°C (20°F):
• Start both engines to allow for full 5’ warm-up.
• Engine anti-ice on (regardless of environmental conditions).
• After warm-up is complete, advance both throttles to 1.2 EPR and check for normal EPR increase.
• If EPR indications are not approximately equal for both engines, allow engines to warm up for additional 2’
• Advance throttles again to check for normal EPR increase, and if still abnormal, contact MCC.

Note: Failure to comply with above procedure may result in erroneous EPR indications on takeoff roll.

If OAT ≤ -35°C (-30°F):
• Operate engine(s) at idle for 2’ before advancing throttle.

Question 5

(88) Positions and function of fuel heat switch

Answer 5

• OFF - Removes power from fuel heat circuit following completion of fuel heat cycle.
• ON - (Momentary) Timer is energized for one minute. Respective fuel heat valve opens, supplying high stage bleed air to the air/fuel heat exchanger.
• Fuel heat is not installed on the MD-90.

Question 6

(90) What automatically occurs with APU pneumatics when a L/R TAIL TEMP HIGH light illuminates?

Answer 6

• APU pneumatic duct depressurizes automatically on L/R TAIL TEMP HIGH light

Question 7

(90) Describe the engine vibration display:

Answer 7

• Engine vibration displays show vibration level from 0 to 9.9 (normal range is approximately 0.0 to 4.0).

Question 8

(88, 90) What conditions would lead to MANUAL ABORTED START (assumes a manual start on the MD-90) for both MD-88/90?

Answer 8

• No N2 rotation
• No oil pressure prior to 20% N2
• Rapid EGT rise toward limit.

Question 9

(88, 90) What conditions would lead to MANUAL ABORTED START for MD-88?

Answer 9

• No N2 rotation
• No oil pressure prior to 20% N2
• Rapid EGT rise toward limit.

MD-88 only
• No N1 rotation prior to 20 % N2
• No fuel flow indication or EGT rise within 20 seconds 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.

Question 10

(88, 90) What conditions would lead to MANUAL ABORTED START (assumes a manual start on the MD-90) for MD-90?

Answer 10

• No N2 rotation
• No oil pressure prior to 20% N2
• Rapid EGT rise toward limit.

MD-90 only
• No N1 rotation prior to 33% N2
• No EGT rise w/in 20 sec. after fuel flow
• Engine vibrations above 4.0

Question 11

(All) Recall the required engine warm up period prior to T/O power application:

Answer 11

• Start second engine in sufficient time (5’ minimum if possible if engine has been shut down more than 2 hrs) to achieve 2’ at idle prior to takeoff.

Question 12

(All) Recall max APU start and operating altitude:

MD-88 / 90

Answer 12

• Max altitude for electric start: FL 370
• Max altitude for windmill start: FL 300
• Max operating altitude is FL 370

MD-90
• Max altitude for electric start: FL 350 (All APU starts are electric)

Question 13

(90) Understand what conditions will cause an AUTO ABORT during automatic start on the MD-90:

Answer 13

• Normal mode performs AUTO ABORT for hot start, hung start, locked N1 rotor, ignition failure, electronic control lost, engine stall and EGT failure.
• AUTO-ABORT feature inhibited ≥ 50% N2

NOTE: No AUTO ABORT is available for low oil press or high vibration.

Question 15

All) Recall the required engine cool down time prior to engine shutdown:

Answer 15

• Engines require 3’ cool down prior to shutdown.

Question 15

(88, 90) Max altitude to use APU electrics:

Answer 15

• MD-88: FL 370

* MD-90: FL 370

Question 16

(All) Describe when FUEL control lever / FUEL switch should be placed to ON during an engine start:

Answer 16

MD-88
• FUEL lever ON at max motoring rpm (usually 22-24% N2) with EGT < 100°C.
• Minimum N2 for FUEL lever ON is 20%.

MD-90
• FUEL switch ON at max motoring RPM (usually 25-26% N2) with EGT < 250.
• Min N2 for FUEL switch ON is 15%. Fuel flow will not begin until 30 sec. after start valve has opened

Question 17

(88, 90) Max altitude to use APU Pneumatics:

Answer 17

MD-88
• In flight, APU is used for electrical power only.

MD-90
• Can supply pneumatics up to 20,000 feet.

Question 18

(88) Function of the MAN EPR SET Knobs:

Answer 18

• 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.

Question 19

(88, 90) Minimum oil quantities for dispatch at maintenance and non-maintenance stations:

Answer 19

MD-88
• Non-maintenance station: 8 qts.
• Maintenance station: 12 qts.

MD-90
• Non-maintenance station: 12 quarts.
• Maintenance station: 16 quarts.
• After engine start: 8 quarts.

Question 20

(88, 90) Describe the function of the ENG SYNC Selector:

Answer 20

MD-88
• N1 - Left engine N1 is matched to right engine N1 (rpm)
• N2 - Left engine N2 is matched to right engine N2 (rpm)
• OFF - EPR synchronization is available. N1 and N2 synchronization is disabled.

MD-90
• OFF - (EPR sync selected) System matches left engine EPR command to the right engine’s.
• N1 - (N1 sync selected) The system matches left engine N1 to the right engine’s.

Question 21

(88, 90) Positions and function of ENG IGN Selector (MD-88)

Answer 21

MD-88
• SYS A - Selects igniter A w/ fuel ctrl lever ON.
• SYS B - Selects igniter B w/ fuel ctrl lever ON.
• OFF - Removes power from all igniters.
• BOTH - All igniters powered w/ fuel ctrl lever ON.
• OVRD - Provides power to igniters in both engines, bypassing fuel control levers.

Question 22

(88, 90) Positions and function of ENG IGN switch. (MD-90)

Answer 22

MD-90
• AUTO - (Normal) Ignition functions controlled by the EEC (auto-abort available). System automatically alternates between A and B systems for normal engine starts or provides dual ignition for T/O, approach, engine anti-ice ON, sub-idle (N2) conditions, engine surge and throttle past frangible gate.
• ON - EEC continuously powers both igniters (auto-abort not available).

Question 23

(88) Function of the FUEL Control Levers on the MD-88:

Answer 23

• ON - Normally completes ignition circuit, then turns on fuel.
• OFF - Shuts off fuel, then ignition.

Question 24

(90) Function of MD-90 FUEL Control Switches

Answer 24

• OFF- EEC closes fuel valve
• ON – Allows EEC to open fuel valve at fuel metering unit

NOTE: Fuel flow will not begin until 30 seconds after the start valve has opened.

Question 25

(90) Understand the operation of normal / emergency reverse thrust on the MD-90:

Answer 25

• MD-90 is equipped with cascade-type reversers.
• Activation of reverse thrust > 60 kts provides max of 1.30 EPR.
• Activation of reverse thrust < 60 knots provides max of 1.07 EPR.
• If initiated > 60 kts, pulling reverse thrust levers past Overrated Thrust (ORT) gate activates emergency reverse thrust increasing reverse thrust an additional 10%.

NOTE: Use of emergency reverse thrust generates an “ENGINE SYSTEM FAIL” message on the OAP and necessitates an engine inspection prior to subsequent operation.

Question 26

(88, 90) Function/indications of the TEST Button on the Thrust Rating Panel (TRP):

Answer 26

Pushing button causes following readout displays:
• RAT: Displays 12° ± 1
• EPR LIMIT: Displays 2.08 ±.01
• All lights on panel should be extinguished.
• When button is released
- RAT readout shows ambient temperature
- EPR readout will display dashes.
- NO MODE light should be illuminated.

NOTE: There is no test on the MD-90 TRP.

Question 27

(88, 90) Function of the NO MODE Annunciator Light (amber) on the Thrust Rating Panel (TRP):

Answer 27

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.

MD-88 only
• No selection made since TRP was tested.
• T.O. flex selected and ART switch is not OFF.

Question 28

(88) Abnormal bleed configurations that cause a NO MODE Annunciator Light (amber) on the Thrust Rating Panel (TRP):

Answer 28

• Airfoil ice protection on and one or both pneumatic crossfeeds open and engine anti-ice off
• T.O. or T.O. FLX selected, engine anti-ice on, RAT > 10° C
• GA selected, engine anti-ice on, RAT > 14° C
• MCT selected, airfoil ice protection on, both pneumatic crossfeeds open
• CL selected, airfoil ice protection on, and one pneumatic crossfeed open.
MCT, CL, or CR selected with both packs off.

Question 29

(88, 90) Function of the APU AIR Switch in the AIR COND COLDER position:

Answer 29

• The turbine bypass valves close, resulting in increased differential pressure across the air conditioning turbine to provide colder air, but at a reduced volume.
• Note - Do not use this position with the engine(s) running

Question 30

(90) Functions/indications of the N1 Mode on the MD-90

Answer 30

• DEFAULT N1 mode operation occurs when EEC is not able to measure or control thrust using a valid EPR. The respective N1 MODE select switch illuminates DEFAULT.
• SELECTED N1 mode operation is obtained by either pressing respective N1 MODE select switch, pushing throttle levers beyond overrated thrust gate, or by utilizing emergency reverse thrust. Respective N1 MODE select switch illuminates SELECT.
• When an engine is in N1 mode, full throttle can cause EEC to control engine at a thrust level in excess of that allowed by max EPR limit. In this mode, overspeed protection is provided but EGT must be monitored to insure that EGT limits are not exceeded.
• Engine may be returned to EPR mode by retarding throttle levers below the overrated thrust gate and pressing N1 MODE select switch to extinguish the DEFAULT or SELECT indication.
NOTE: Autothrottles are not available when engine(s) are in N1 mode.

Question 31

(88) Understand the function of the Automatic Reserve Thrust (ART) System on the MD-88:

Answer 31

• The ART system provides an increase in thrust with an engine failure or a windshear encounter.
• If either condition occurs during a normal power takeoff the operating engine(s) will automatically advance to MAX thrust.

Question 32

(88) Conditions under which ART system activates

Answer 32

The ART (auto reserve thrust) system activated when:
• There is a 30% differential in N1
• Windshear is detected
• The selected DFCG fails
• DFGC’s are manually switched
• N1 input fails.

Question 33

(88, 90) When is APU bleed air available on MD-88 / MD-90? Note on MD-90 ground operation?

Answer 33

MD-88
• After start, a 60 sec warm-up occurs.
• During shutdown, a 60 sec cool-down occurs.
• APU bleed air not available during warm-up and cool-down period.

MD-90
• No warm-up needed prior to using pneumatic air.

NOTE: During MD-90 ground operation, moving the APU AIR Switch to ON will open ram door. When open, ram door extends even with tail skid. Moving APU AIR Switch to OFF retracts ram door, preventing ram door damage in event of tail skid strike during takeoff rotation or ldg flare.

Question 34

(88) Meaning of OAP message ART INOP:

Answer 34

• System has failed self-test
• ART switch is in OFF position used when accomplishing:
- Alternate (flex power) - or -
- maximum power takeoff
(anything other than a normal power takeoff).