Powerplant Flashcards
What does the ECU provide?
- Ground idle fuel scheduling
- Prop underspeed governing - 785 rpm
- Prop governing in reverse - 1140 rpm
- Quiet taxi mode
- Fuel scheduling in forward power range
- Power uptrim
- Bleed valve operation
What is the indication of an ECU failure?
Caution light “#_ENGINE MANUAL”, change in power output by engine
What controls fuel scheduling?
ECU
What are the MTOP limits?
Torque: 111% ITT: 800 Max Nl: 104% Max Nh: 102.7% Max Np: 1212 rpm Oil Press: 55-65 PSI Oil Temp: 45-115 C
What is the purpose of the engine intake bypass doors?
Prevent solids and precipitation from entering the engine
What are the start malfunctions and action to be taken?
Hot Start: CL Fuel Off, Ignition Off, Motor engine 15 seconds
Hung Start: CL Fuel Off, Ignition Off, Motor engine 15 seconds
Failure to light: CL Fuel Off, Ignition Off, Motor engine 15 seconds
No Starter Cut-out: Starter Off, DC Ext Power Off
Low or No Oil Pressure: CL Fuel Off, Starter Off
When does the starter change to a generator during start?
63 +/- 2% Nh
What are the starter limits?
1 on 2 off, 1 on 2 off, 1 on 30 mins off
What is the maximum ITT for start?
950 degrees C
What is the normal max ITT?
800 degrees C
When does the ENG OIL PRESS warning light illuminate?
42 +/- 2 degrees C
What is the minimum in flight Nh?
66%
What services are operated on the accessory gear box?
DC Starter/Generator, engine oil pressure, scavenge pumps, engine high pressure fuel pump
What are the indications of UPTRIM?
Power Uptrim light illuminates, power increase in the engine
What will happen if the ECU fails?
Caution light illuminates (#_MANUAL ENGINE), affected engine will increase power output
What is the maximum in flight prop RPM setting?
1212 RPM
What prop RPM does the ECU provide underspeed governing to (ground governing)?
785 RPM
What is the propeller restricted range?
500-780 RPM
What is the auto-feather delay?
3 seconds
When will the auto-feather ARM?
Push the AUTOFEATHER Switchlight, Power Levers advanced so both engine torques exceed 38% and both Power Levers are advanced to meet PLA and OAT requirements
When will the auto-feather activate?
Activates when the torque on one engine is less than 28% while the torque on the other engine is more than 38% and both PL are advanced to meet the PLA and OAT requirements
What propeller over speed protection is there?
Hydraulic (1250) and pneumatic (1308)
How do you manually feather the propeller?
Move CL to the START/FEATHER position, alternate feather switch activated
What RPM difference will the syncrophase sync the propellers?
20 RPM
What RPM will the over-speed governor hold the RPM at?
1250 RPM (Hydraulic)
When does the ECU over-speed protection occur?
1308 RPM (Pneumatic)
When do the propeller ground range advisory lights illuminate?
Props in ground BETA range (blade angle decreasing through 16.5 degrees)
What services are operated from the prop reduction gear box?
- Main hydraulic pump
- Propeller Control Unit
- PCU pump
- Propeller Over-speed Governor
- 115 VAC Generator
Where does the PCU get it’s oil from?
Engine oil system in the Reduction Gear Box
What happens if the prop loses oil?
Prop tries to go to flat pitch, pitch lock engages
