DB's SY 737 Engine

Question 0

ENGINE START switches - OFF

Answer 0

1. Normal position
2. Both igniters are activated when Start Levers in IDLE and:
   • Uncommanded rapid decrease in N2 or
   • N2 is 50%-57%
   • In flight - N2 is between idle and 5%

Question 1

Engine Start Switches - GRD

Answer 1

1. Opens start valve
2. Closes engine bleed valve
3. Ground Starts - Arms selected igniter (when start lever moved to IDLE)
4. Air Starts - Arms both igniters (when start lever moved to IDLE)
5. Releases to OFF at start valve cutout (56%)

Question 2

ENGINE START switch - CONT

Answer 2

1. Provides ignition to selected igniters (with engine on and start levers in IDLE)
2. In flight - Provides ignition to both igniters when N2 is below idle with start lever in IDLE.

Question 3

ENGINE START Switches - FLT

Answer 3

Both igniters activated (when start lever in IDLE)

Question 4

REVERSER lights - ON

Answer 4

One or more of the following:

1. Isolation valve or thrust reverser control valve is not in commanded position
2. At least one thrust reverser sleeve not in commanded state
3. Auto-restow circuit has been activated
4. Synchro shaft lock circuitry failed

Question 5

ENGINE CONTROL lights - ON

Answer 5

Non-dispatchable fault in the Engine Control system

Question 6

When are the ENGINE CONTROL lights active?

Answer 6

1. Engine is operating and
2. Airplane is on the ground and
   • Below 80 prior to takeoff or
   • 30 secs after touchdown

Question 7

EEC Switches - lights illuminated

1. ON only
2. ALTN and ON
3. ALTN only

Answer 7

1. Normal control mode
2. EEC automatically in (soft) alternative mode or manually in hard alt mode by retarding thrust levers idle (not by pressing EEC switch)
3. EEC manually selected to (hard) alternate mode by pressing EEC switch

Question 8

What type of engines are installed?

Answer 8

CFM56-7B

Question 9

What does soft alternate mode on the EEC do for us?

Answer 9

The EEC uses the last valid fight conditions to define engine parameters which allows the mode change to occur with no immediate change in engine thrust.

Question 10

What does hard alternate mode in the EEC do for us?

Answer 10

The EEC reverts to alternate mode (factory presets) thrust schedule. Hard alternate mode thrust is always equal to or greater than normal mode thrust for the same lever position.

Question 11

How does a loss of either DEU affect our engines?

Answer 11

Loss of either DEU results in a loss of signal to both EECs, which reverts both EECs to alternate mode to prevent the engines from operating on a single source of data.

Question 12

How does the EEC actually control the speed of the engine?

Answer 12

The EEC compares commanded N1 to actual N1 and adjusts fuel through the HMU to achieve the commanded N1.

Question 13

At what N2 speed does the starter normally cutout?

Answer 13

56%

Question 14

During an engine start, what does a flashing white box around the EGT indicate?

Answer 14

Impending hot start or a compressor stall has occurred

Question 15

Will the engine ever automatically abort an engine start?

Answer 15

Yes, the EEC automatically turns off the ignition and shuts off fuel to the engine for an impending hot start or stall (flashing white box surrounding EGT) or wet start (15 secs after start lever is moved to idle with no EGT rise).

Question 16

During an engine start, what does it mean if the EGT (both box and dial) display turns red?

Answer 16

The EGT has exceeded the starting limits (725°).

Question 17

When will the engine auto-relight provide flameout protection?

Answer 17

When an uncommanded rapid decrease in N2 occurs or N2 is below idle RPM (50%).

Question 18

What system normally moves the thrust reverser translating sleeves? What is the back up should that system fail?

Answer 18

Normally hydraulic pressure by the respective system (A and B). Alternate operation is available through the standby hydraulic system (operates at a slower rate than normal hydraulics).

Question 19

What percentage of air is bypassed air around the engine core?

Answer 19

80%

Question 20

From soft alternate mode, what are two ways to enter into hard alternate mode?

Answer 20

1. Press the EEC switch

2. Move thrust lever to idle

Question 21

How is the IDG oil cooled?

Answer 21

Fuel and air cooled