Engines

Question 1

What provides pressurized fuel for the engine?

Answer 1

fuel pumps located in the fuel tanks

Question 2

How is the fuel heated?

Answer 2

It passes through two fuel/oil heat exchangers where IDG oil and main engine oil heat the fuel.

Question 3

What is BRM and how long can it last?

Answer 3

Bowed Rotor Motoring (BRM)
Starts after the Engine Start Switch has been moved to the GND position and before the Engine
Start Lever is moved to IDLE.

6-90 seconds on the ground only

Question 4

How many igniters are there?

Answer 4

Each engine has two igniter plugs.

Question 5

Which buses power the ignitors and why is this important with loss of normal AC?

Answer 5

The left igniter plug receives power from the associated AC transfer bus. The right igniter plug receives power from the AC standby bus.

Important because right still works on standby power.

Question 6

When do the secondary engine instruments appear?

Answer 6

• when MDS initially receives power
• when selected by the Multi-Function Display (MFD)
• in flight when an Engine Start Lever is moved to CUTOFF
• in flight when an engine N2 rpm is below idle rpm (ENG FAIL)
• when a secondary engine parameter exceeds normal operating range.

Question 7

Where is the accessory gearbox located? Name the accessories.

Answer 7

On the bottom of the engine

Oil pump
Fuel pumps
IDG
Hydraulic pump
Starter

Question 8

Which engine indications are always displayed on the selected IB display unit?

Answer 8

N1 and EGT are the primary engine indications. The primary engine indications are normally displayed on the Captain’s inboard DU

Question 9

What indicates caution ranges and maximum values of the engine parameters?

Answer 9

N1, EGT, and N2 have operating limits indicated by redlines. EGT also displays
an amber caution limit. If one of these indications exceeds the red or amber line,
the digital readout, box, pointer, and indicator change color to red or amber.
The oil temperature and oil pressure vertical indications have a caution range and
an operating limit redline. If the oil temperature or pressure reaches the caution
range, the digital readout, digital readout box, and pointer all change color to
amber. If one of these indications reach the operating limit, the digital readout,
digital readout box, and pointer all change color to red.

Question 10

What happens to the readout if one of these parameters exceeds normal operating range or limit?

Answer 10

the digital readout, digital readout box, and pointer all change color to red

Question 11

What happens to the indications when electrical power is lost to the EEC?

Answer 11

When the EEC is not powered, N1, N2 and oil
quantity are displayed directly from the engine sensors.

(Check this answer)

Question 12

Which switch provides initial electrical power to the EEC?

Answer 12

Positioning the engine start switch to GRD supplies electrical power to the EEC

Question 13

How many modes of control are there for the EEC? Are these automatic or manual?

Answer 13

• Normal
• Soft alternate (automatic)
• Hard alternate (manual by pressing the EEC switch or regarding thrust to idle)

Question 14

Are engine shortfalls or exceedances possible when operating in soft alternate mode?

Answer 14

YES

Question 15

How can we enter hard alternate mode?

Answer 15

By either retarding the thrust lever to idle or manually selecting ALTN with the EEC switch on the aft overhead panel.

Question 16

Does the EEC provide EGT exceedance protection?

Answer 16

Only on the start

Not in flight

Question 17

What conditions would cause the EEC to cut off fuel?

Answer 17

If an unacceptable high asymmetric thrust condition is detected the EEC automatically shuts off fuel to the affected engine.

If an uncontrollable N2 overspeed condition is detected the EEC automatically shuts off fuel to the affected engine.

Question 18

What type of abnormal starts does the EEC provide protection for on the ground?

Answer 18

During ground starts, the EEC monitors engine parameters to detect impending
hot starts, engine stalls, EGT start limit exceedances, and wet starts.

These protection features do not function during inflight starts.

Question 19

What phase of flight is Thrust Control Malfunction Accommodation (TCMA) active and what does it do?

Answer 19

On the ground (RTO and Landing)

If an unacceptable high asymmetric thrust condition is detected the EEC automatically shuts off fuel to the affected engine.

Question 20

What happens at starter cutout at approximately 63%?

Answer 20

• power is removed from the start switch holding solenoid.
• The engine start switch returns to AUTO,
• the engine bleed air valve returns to the selected position,
• the start valve closes.

Question 21

When is Icing Idle selected and at what altitude does is schedule the increase?

Answer 21

Icing idle is selected in flight if the flaps are up, the main gear is not down and locked and the engine anti-ice is on.

The EEC begins transition from minimum
flight idle at 30,400 feet and increases idle in the descent to provide full icing idle at and below 22,000 feet.

Question 22

Why is Approach Idle higher than Flight Minimum Idle?

Answer 22

Approach idle improves engine acceleration time in the event of a go–around.

Question 23

What powers the thrust reversers?

Answer 23

Hydraulics