Engine Flashcards
3 major assemblies
Power section
Propeller gearbox
Torquemeter
Unique features
2 FADEC
GMAD
NIU
Primary purpose of Propeller gearbox
Transmit shaft power from torquemeter to propeller, reduce shaft rpm, provide power to GMAD
GMAD provides drive pads for
GOOPH
G: AC Generator
O: Oil pressure pump
O: overspeed governor
P: PCU
H: Hydraulic pump
Torquemeter primary function
Transmit engine output to PGB and supply reference to the FADECS
Power unit accessory drive (PUAD)
FASSFA
F: FPMU
A: Alternator Stator
S: Starter
S: scavenge pump
F: FCOC
A: Accessory drive sump
FCOC
Fuel cooled oil cooler
Controlling FADEC is determined by:
- Engine start with WOW, selection automatically alternates
- Serious FADEC fault automatic shifts to alternate FADEC
- ALT selection on control panel
NG
Gas generator speed
NP
Power turbine speed
MGT
Measured gas temperature
Engine PMA provides electrical power for the FADEC after engine speed reaches:
40%
Propeller speed governing is accomplished by:
Varying blade angle or engine fuel flow
Nacelle interface unit (NIU)
- Provides 1553 & RS422 communications
- Provides indications of oil temp, px & quantity, oil cooler flap position and fuel flow
- Controls oil cooler flap and engine/nacelle anti-ice valves
4.provides engine health & usage monitoring
A ___ gallon oil tank located in each ____
20
Nacelle
The 20 gallon oil tank has ___ oil capacity with the remaining being air
12 gallon
0.66 gallon dedicated reservoir for
Auxiliary feather pump oil supply
Oil is gravity fed from tank, through a shutoff valve to:
GMAD/PGB pump & Engine power section pump
Oil cooler augmentation supplements normal oil cooling during:
And uses:
Exceeded ground operations
14 stage bleed air when the per levers are below flight idle
Oil cooler augmentation is operating when:
1.Oil cooler flap position is greater than 80%
2. Oil temp is above 80 C
3. Airspeed less than 50 knots
4. Pwr levers less than flight idle
5. Weight on wheels
ACAWS alerts If oil cooler augmentation system fails on
Caution!
Damage to the oil cooler flap occurs unless the crew opens the cooler flap full open
Starting system consists of
Air turbine starter and starter regulating and shutoff valve
Engines started using a combination of
Electrical power and low pressure bleed air
Min bleed air pressure for start
22 PSI
For start MGT must be below
175 C
During start:
At 14% NG
The FADEC arms the fuel ignition circuits
4 sec later, ignition is energized and shutoff valve opens to start fuel flow
Normal time from light up to stabilized NG is 20-25 sec
Starter cutout occurs at
65% NG
Time from starter switch select to NP on speed
30 sec
After motor, wait ___ after NG reaches __
30 sec
0
On the ground, AUTO mode opens the oil cooler flap when the oil cooler outlet temp is greater than
75 C
And retracts flap when temp is less than 60
Coolest oil temperature is achieved when flap is
100 percent open
In air with gear extended, AUTO mode opens oil cooler flap when temp is greater than ___ and retracts when temp is less than ___
82
76
In flight, with gear retracted, AUTO mode:
Closes oil cooler flap for optimum in flight cooling
PMA
Permanent magnet alternator
PMA powers
FADEC and engine exciters
Starter duty cycle
70 sec cycle, 5 cycle max then 20 min cooldown
On start:
NG in
EPSI
GPSI
10 sec for NG
EPSI 15 sec after NG
GPSI 15 sec after NP
Pulling fire handle (9 things)
- Nacelle shutoff valve closed
- Engine oil shutoff valve closed
- Extinguishing AGENT switching avail
4.Fire extinguisher directional control valves positioned
5.firewall shutoff valve closed
6.firewall hydraulic shutoff valves are closed
7.BAU commands prop aux feather pump for 20sec - Data bus message sent to FADEC to feather prop and shut down engine
- Shutoff valve in the engine FPMU, backup power 1/4 is utility battery; 2/3 is avionics battery
