Engines

Question 1

What does the FADEC do when it detects a hung or hot start?

Answer 1

• automatic recovery sequence without an ECAM message
• dual ignition (A+B) is applied
• fuel will be commanded OFF, and then re-commanded ON within 0.5 s

Question 2

Engine Damage Identifications

Answer 2

• N1 = 0 (or amber crosses)
• N2 = 0 (or amber crosses)
  ‐ Rapid increase of the EGT above the red line
  ‐ Important mismatch of the rotor speeds, or absence of rotation
  ‐ Significant increase of aircraft vibrations, or buffeting, or both vibrations and buffeting
  ‐ Hydraulic system loss
  ‐ Repeated, or not controllable engine stalls
• check adv on E/W display if pulsing

Question 3

How many compressor and turbine stages (IAE)

Answer 3

• single N1 fan
• 4 stage LP compressor
• 10 stage HP compressor
• 2 stage HP turbine
• 5 stage LP turbine

Question 4

How many furs nozzles and igniters (IAE) & (CFM)

Answer 4

• 20 fuel nozzles

- 2 igniters

Question 5

Which bleed source is used for engine anti ice?

Answer 5

7th stage of HP compressor (IAE)

5th stage of HP compressor (CFM)

Question 6

What is the nacelle assembly composed of?

Answer 6

• air inlet cowl
• two fan cowls
• two C-ducts
• common nozzle assembly

Question 7

Automatic start sequence (IAE)

Answer 7

After ENG MASTER ON:

• EEC commands LP fuel valve and starter valve to open
• After 30s (min N2 10-16%; max N2 25%) ignition A or B commanded on
• At 43% N2 EEC commands starter valve to close and ignition cut off

Question 8

Thrust rating and Bypass Ratio (IAE)

Answer 8

Thrust rating: 26,600 lbs

Bypass Ratio: 4.8:1

Question 9

Where is EPR (Engine Pressure Ratio) measured?

Answer 9

From the P2/T2 (total pressure and temp) sensor located inside the inlet cowl at the 12 o’clock position

Question 10

How is the FADEC powered

Answer 10

• self powered by PMA above 10% N2
• below 10% N2 powered by electrical system:
  
  • 5 mins after aircraft power up
  • ENG MODE selectors ING/CRANK
  • 5 mins after engine shutdown

Question 11

Describe the path air takes once it enters the inlet cowl

Answer 11

• All air entering the engine passes through the inlet cowl to the N1 fan.
• air continues on to either the engine core or the bypass duct
• Air entering through the engine core passes through the fixed inlet guide vanes to the LP compressor and then to the HP compressor, combustion chamber, HP turbine, LP turbine before finally exiting through the common nozzle assembly.
• Air that enters through the bypass duct passes through the fan outlet guide vanes and is exhausted through the common nozzle assembly
  * The engine nacelle provides aerodynamic efficiency and protects the engine and its accessories*

Question 12

How is the nacelle ventilated?

Answer 12

• Ram air enters through an inlet located on top of the air intake cowl, goes through the fan case compartment and is exhausted at the bottom of the fan cowl doors through two ventilation grilles.
• Ventilation around the engine core is also provided by fan air circulating around the turbine case, which is exhausted at the bottom of the C-duct cowls through the thrust recovery nozzle

Question 13

Thrust Rating and Bypass Ratio (CFM)

Answer 13

Thrust Rating: 27,000 lbs

Bypass Ratio: 5.4:1

Question 14

How many compressor and turbine stages (CFM)

Answer 14

• single N1 fan
• 4 stage LP compressor
• 9 stage HP compressor
• 1 stage HP turbine
• 4 stage LP turbine

Question 15

What controls the LP fuel valve?

Answer 15

driven by two electric motors, controlled by:

1) engine master switch
2) related fire push button.

Question 16

Which hydraulic systems operate the thrust reversers?

Answer 16

Green Hydraulics - left engines upper and lower actuators

Yellow Hydraulics - right engines upper and lower actuators

Question 17

Thrust reverser deployment requirements

Answer 17

• rearward thrust lever movement received by EEC
• left and right main gear compressed signal received by LGCIU
• TLA reverse signal received by at least one SEC

Question 18

What triggers ENG 1(2) REVERSE UNLOCKED master caution?

Answer 18

The Linear Variable Differential Transformer (LVDT) senses an un-commanded reverse in excess of 15% of actuator travel

Question 19

What is the preferred duct pressure for a successful engine start?

Answer 19

30 - 40 PSI

Question 20

Which events cause an auto engine abort? (ENG 1(2) START FAULT)

Answer 20

1 - Hung start.
2 - Hot start.
3 - No N1 rotation.
4 - Starter valve failure.
5 - Ignition failure.
6 - Stall.
7 - No light off.
8 - Pressure Raising Shutoff Valve failure.
9 - EGT >250°C when restart.

Question 21

What is driven by the accessory gear box (CFM)

Answer 21

• the Integrated Drive Generator (IDG);
• FADEC alternator;
• hydraulic pump;
• fuel pump and HydroMechanical Unit (HMU);
• Lubrication Unit (containing the oil pumps).​