Engines Flashcards
What does the FADEC do when it detects a hung or hot start?
- 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
Engine Damage Identifications
- 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
How many compressor and turbine stages (IAE)
- single N1 fan
- 4 stage LP compressor
- 10 stage HP compressor
- 2 stage HP turbine
- 5 stage LP turbine
How many furs nozzles and igniters (IAE) & (CFM)
- 20 fuel nozzles
- 2 igniters
Which bleed source is used for engine anti ice?
7th stage of HP compressor (IAE)
5th stage of HP compressor (CFM)
What is the nacelle assembly composed of?
- air inlet cowl
- two fan cowls
- two C-ducts
- common nozzle assembly
Automatic start sequence (IAE)
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
Thrust rating and Bypass Ratio (IAE)
Thrust rating: 26,600 lbs
Bypass Ratio: 4.8:1
Where is EPR (Engine Pressure Ratio) measured?
From the P2/T2 (total pressure and temp) sensor located inside the inlet cowl at the 12 o’clock position
How is the FADEC powered
- 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
Describe the path air takes once it enters the inlet cowl
- 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*
How is the nacelle ventilated?
- 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
Thrust Rating and Bypass Ratio (CFM)
Thrust Rating: 27,000 lbs
Bypass Ratio: 5.4:1
How many compressor and turbine stages (CFM)
- single N1 fan
- 4 stage LP compressor
- 9 stage HP compressor
- 1 stage HP turbine
- 4 stage LP turbine
What controls the LP fuel valve?
driven by two electric motors, controlled by:
1) engine master switch
2) related fire push button.
Which hydraulic systems operate the thrust reversers?
Green Hydraulics - left engines upper and lower actuators
Yellow Hydraulics - right engines upper and lower actuators
Thrust reverser deployment requirements
- 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
What triggers ENG 1(2) REVERSE UNLOCKED master caution?
The Linear Variable Differential Transformer (LVDT) senses an un-commanded reverse in excess of 15% of actuator travel
What is the preferred duct pressure for a successful engine start?
30 - 40 PSI
Which events cause an auto engine abort? (ENG 1(2) START FAULT)
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.
What is driven by the accessory gear box (CFM)
- the Integrated Drive Generator (IDG);
- FADEC alternator;
- hydraulic pump;
- fuel pump and HydroMechanical Unit (HMU);
- Lubrication Unit (containing the oil pumps).
