AD FAA-2007-27552

The FAA is adopting a new airworthiness directive (AD) for Hartzell Propeller Inc. model HC-E4A-3( )/E10950( ) propellers. This AD requires initial and repetitive inspections and rework of the propeller blade retention radius, and replacement of the propeller blade thrust bearing, for each blade. This AD results from reports of excessive propeller vibration and of damaged or broken propeller blade thrust bearings found during routine and investigative propeller disassembly. We are issuing this AD to prevent propeller blade separation, damage to the airplane, and possible loss of airplane control.