Summary
The Federal Aviation Administration (FAA) proposes to adopt a new airworthiness directive (AD) that is applicable to Hartzell Propeller Inc. model HC-B3TN-5( ) propellers, with blades part number (P/N) T10176H(B,K)-5 or T10178H(B)-11(R) that are installed on Mitsubishi Heavy Industries, Ltd, MU-2 series airplanes. This proposal would require replacement of those blades with blades of the latest design. This proposal is prompted by a report of in-flight propeller blade separation that caused a severe out-of-balance condition, damage to the airplane, and resulted in engine shutdown and a safe landing. The actions specified by the proposed AD are intended to prevent propeller blade separation, damage to the airplane, and possible loss of the airplane.