Following a propeller strike with damage to the propeller it is imperative that checks
are carried out to ensure that engine internal component damage has not occurred.
If the engine is run after a propeller strike without these checks having been carried
out, further catastrophic damage can destroy the engine, sometimes several hours
The following checks are made during a shock load check:
Propeller shaft and hub is tested for cracks and run out
Gears in the gearbox are tested for cracks
Gearbox casing in testing for cracks around the main bearing
Propeller shaft bearings are replaced
Crankshaft PTO end journal is tested for run out
Crankshaft magneto flywheel end journal is tested for run out
Crankshaft phasing checks are carried out
Woodruff key is checked for distortion and cracks
Crankshaft woodruff keyway is checked for cracks
Magneto flywheel is checked for cracks around the hub
Slipper clutch is checked for correct slipping torque
When a slipper clutch is fitted to the engine the crankshaft and flywheel are protected.
However, damage may still occur within the gearbox and the first 5 checks in the
list are necessary.