ATA 61 Propeller Flashcards
How is the propeller blade angle controlled in
a) Beta Range
b) Constant Speed Range
a) By the power lever
b) Controlled by a governor in the PCU, which regulate Np in response to Condition Lever settings
What will happen to the propeller blade angle if the oil pressure is lost during flight?
A Pitch Lock feature engages to prevent aerodynamic loads from reducing blade angle more than 1 degree adn propeller speed increasing more than 2% from the point of pressure loss
What is the purpose of the Propeller Control Unit?
The PCU meters the engine oil to one side of the pitch change mechanism in the hub to reduce blade angle (fine) which is opposed by constant oil pressure supplied to the mechanism to increase blade angle (coarse)
How can the propeller be feathered?
- Condition Levers to START & FEATHER
- Autofeather
- Manual alternate feather
The propeller restricted range is between…?
500-780 rpm
The propeller Beta Backup Protecting System;
a) What is the purpose
b) When will the system be disarmed
a) Propeller overspeed protection. Increases propeller angle if blade angle below flight idle with Power Levers above FLT IDLE gate
b) Power Levers 13° below FLT IDLE
When is the propeller Autofeather System ARMED?
Torque > 50 %
Power Levers > FLT IDLE + 28° on both engines
The propeller Alternate Feather Pump;
a) What is the purpose?
b) How can the pump be started?
c) The oil reservoir for the pump is located where?
d) The operating time for the pump is?
a) To permit propeller feathering or unfeathering in the event of engine oil supply failure or with the engine shut down
b) Automatic start with autofeather or manually by switches
c) In the reduction gearbox
d) 15 seconds
The propeller synchrophase system - The master propeller is?
1 propeller
What is the maximum take-off rating of a PW-121 engine?
2150 shp with automatic uptrim
Tq: 107,5, ITT 816, Nh 100%, 1212 rpm, 55-65 PSI, 45-115°C
The engine is a free-turbine, two spool engine, means..?
No mechanical connection between the gas generator (NH gen and NL) section and the propeller
The engine intake bypass doors;
a) Location
b) Operation
c) Indication
a) One in each nacelle at the rear lower (plenum) part. Prevents solids and precipitation from accumulating
b) Normally opened during icing conditions. Door opening and closing is controlled by ENGINE INTAKE BYPASS DOOR switchlights on the engine instrument panel
c) ENGINE INTAKE BYPASS DOOR switchlights
PUSH - CLOSED (green)
PUSH - HTR OPN (amber)
- Indicates door open and heater activation
- Heater activates with door open, engine oil pressure above 40 psid,
T< 15°C and AC power available
When will the #1 ENGINE MANUAL caution light illuminate?
When fuel control in ON and an ECU fault occurs the fuel system goes into reversion
How can the Quiet Taxi mode be initiated?
Condition Levers - MIN
Power Levers - FLT IDLE
What will initiate a Power Uptrim?
Engine Failure –> The other engine’s torque will be increased by 10 %
The purpose of the “Fail Fix” (-100) system is?
To maintain continous power (freeze the torque motor in the last position) in the event of ECU failure with engines at take-off power
(Rate selector - TOP, Power Levers FLT IDLE + 28°)
The purpose of the “Uptrim Disable” switchlight is?
When performance calculations show that you must use MTOP, the UPTRIM DISABLE switchlight may be pushed to protect against a possible overtorque condition in event of an engine failure during take-off with MTOP
The Autoignition System will automatically relight an engine if?
- Torque > 50%
- Ignition switch set to AUTO
- Condition Levers not selected to FUEL OFF
How can you abort an engine start?
Condition Lever - FUEL OFF
Engine start, select switch - mid position
What is the maximum starting temperature?
950°C
816 - 850°C max 20 seconds
850 - 950°C max 5 seconds
The Power Levers controls?
- Engine speed in the forward power range;
- Propeller blade angle in the beta range (26° to -11,5°)
The Condition Levers controls?
- Propeller RPM in the forward power range
- Feathering
- FUEL ON/OFF
The Beta Warning Horn sounds if?
The Flight Idle Gates are lifted and the power levers are in a position forward (to prevent further movement to below flight idle) of FLT IDLE and the aircraft is airborne
What is the purpose of the Beta Lockout System?
To prevent propeller overspeed when flight idle gates are lifted and power levers are moved below FLT IDLE when airborne
How is the Beta Lockout System disabled on the ground?
RA < 50 ft and/or WoW on both main wheels will operate GND BETA ENABLE RELAY (Ground signal will energize realy anf disarm Beta Backup protection and Beta Lockout Systems)
What happens when an engine instrument Test Button is pressed?
The pointer will move to a position opposite a blue dot, with an equivalent reading on the digital display
Normal oil pressure is?
55 - 65 PSI
When will ENG OIL PRESS warning light illuminate?
Oil pressure < 42 +/- 2 PSI
