Recommended Action for Sudden Engine Stoppage, Propeller/Rotor Strike or Loss of Propeller/Rotor Blade or Tip

Lycoming Service Bulletin No. 533B

This Service Bulletin identifies propeller/rotor damage conditions and  gives corrective action recommendations for aircraft engines that have had propeller /rotor damage as well as any of the following:

1. Separation of the propeller/rotor blade from the hub

2. Loss of a propeller or rotor blade tip

3. Sudden stoppage

A propeller strike includes:

• Any incident, whether or not the engine is operating, where repair of the propeller is necessary

• Any incident during engine operation where the propeller has impact on a solid object which causes a  decrease  in  RPM  and  also makes a  structural repair of the  propeller  necessary. This incident includes propeller strikes against the ground. Although the propeller can continue to rotate, damage to the engine can occur, possibly with progression to engine failure

• Sudden RPM  drop  on impact to water, tall grass, or similar  yielding medium where  propeller damage does not usually occur.

A propeller strike  can occur at  taxi speeds, during  touch ­and ­go operations with propeller tip  ground contact. In addition, propel er strikes also include situations where  an aircraft is stationary and  a  landing gear collapse occurs causing one or more blades to be bent, or where a hangar door (or other object) hits the propeller  blade. These  instances are  cases of sudden engine stoppage because  of potentially severe side loading on the crankshaft flange, front bearing, and seal.