AW139 PTS - PowerPlant Flashcards
What engine is fitted?
PT6C-67C
How is the engine fitted to the airframe?
By the Torque tube at the front
By 2 mounts at the rear
How many turbine wheels and what do they do?
- Dual stage Power Turbine - powers the MRGB
2. Single stage Compressor Turbine - powers the compressor
What drives the engine accessory gearbox?
The compressor
What engine parameters are displayed in the cockpit?
NG, TQ, ITT (primary)
Oil T & P (secondary)
NF
What controls the engine?
EEC
Electronic Engine Control
What does the engine control do?
Talks to the FCM which adjusts a valve that controls fuel flow to the engine
How does the engine control get its electrical power?
PMA
(Permanent Magnetic Alternator) which provides power when NG>40%
ESS BUS during start
What is the min voltage for start?
23V
What are the ITT Start Limits?
> 869 for 2 secs
Max 1000
What are the engine cycle starter limits?
45s on / 1min off
45s on / 1min off
45s on / 30min off
What are the indications to abort a start?
- Abnormal noise
- No light up in 10 secs
- No rotor turn by 40% NG
- Engine hangs below 54% NG
- 869 for 2 secs (max 1000)
- Starter still engaged above 49% NG
When does the starter disengage?
49% NG
What prevents a hot start
- Pilot intervention
- Good battery voltage prior to start
- EEC gives protection to the engine (at 1000 deg)
Does a red [EEC FAIL] CAS message inhibit the engine overspeed protection?
No
How does the engine anticipate pilot input to maintain rotor speed?
LVDTs fitted to collective
Linear Variable Differential Transducer
What happens to the fuel flow during a red EEC FAIL CAS?
FCM valve maintains present position and allows use of ECLs
Can you manually control fuel flow?
Yes
Put governors in MAN and use the GOV trim stitches on either collective
What is the purpose of load sharing?
The EECs adjust the engines to match either TQ or ITT
normal selection is TQ
Where is load sharing displayed in the cockpit?
Above the PI
TQ or ITT
What does the torque limiter do?
Prevents torque above 114%
protects the gearbox
What happens when you raise the collective when the Tq limiter reaches its limits?
NR will droop until 87% , then the limiter will turn off.
Does the Tq limiter go off if more power is required?
Yes, when NR hits 87%
If selected on, does the Tq limiter go off when OEI?
YES
