OPERATION AND INSTALLATION MANUAL
EN-1320
8.8. Oil leakage
(visible outside or hidden inside)
Cause: Damaged seals
Remedy: Replace gaskets or repair propeller
8.9. Rough running turbine, possibly in limited rpm range only
Cause:
1. Bad static balance
2. Bad dynamic balance
3. Operation in restricted rpm range
Remedy: 1. Rebalance statically, mount balance weights to spinner front plate.
2. Rebalance dynamically, mount balance weights to spinner bulkhead.
3. Refer to Airplane Flight Manual. Check rpm gauge for correct reading. Repair or
replace it necessary.
8.10. Slow reversing or no reversing
If reverse is not possible, the governor and the mechanical linkage between the rotating
propeller and the turbine must be inspected. If necessary, inspect the carbon brush block and
the brass slip ring for damage or wear, or check the beta-valve.
Relief valve pressure is too low, or the internal leakage of the oil transfer system is too high.
8.11. Slow feathering
If more than 10 sec. are needed for full feathering, there is one of the following problems :
1. Sticking blades or pitch change mechanism
2. Control too long or wrong adjusted governor
If no discrepancies are found during inspection, check governor on a test bench, at TPE-331-()
engines, check the feathering valve.
8.12. Start-Lock not reachable
If the start-lock do not engage at the Garrett TPE-331-( ) engines, either the spring is broken or
the piston guide rod is worn out.
Check both parts for their condition, if necessary replace.
61-10-20
TROUBLESHOOTING
Page 8-3
2017-10-06
