OPERATION AND INSTALLATION MANUAL
EN-1320
8.0. TROUBLESHOOTING
8.1. Blade shake
8.1.1. Fore and aft movement
Cause: Blade bearing loose
Remedy: If more than 3 mm, return propeller to the factory or any approved repair station to
correct the pre-load of the blade retention bearing.
8.1.2. Blade angle play
Cause:
Blade bearing loose by seating and/or increased play by wear in the pitch change
mechanism (pitch change pin, pitch change block).
Remedy: If more than 2°, return propeller to the factory or any approved repair station.
8.2. Sluggish rpm change
Cause:
1. Oil is cold
2. Excessive friction
Remedy: 1. Run the turbine until the green arc of the oil temperature is reached. Cycling the
propeller several times and observe if sluggish rpm change is still present.
2. With stopped engine, move the blades by turning them with hands within the
angular play. If excessive friction exist, the blade retention system has to be
inspected, contact factory.
8.3. Surging rpm
Cause:
1. Trapped air in propeller piston
2. Sludge deposit
3. Wrong speeder spring in the governor
4. Wrong pitch stops in the propeller
5. Abrupt movement of propeller or throttle control
6. Instrumental error
Remedy: 1. Move propeller control at least twice every time before flying
2. Clean oil tubes in the turbine in the propeller piston and eventually in the governor
(only possible at the manufacturer´s).
3. Check that the governor part number corresponds to the aircraft data sheet. If the
rpm does not stabilize after 5 periods this is an indication for a wrong speeder
spring, contact factory.
4. Compare pitch values to those of the data sheet. Note static rotational speed.
5. Move the controls carefully and slowly
6. Check tachometer and drive.
61-10-20
TROUBLESHOOTING
Page 8-1
2017-10-06
