Summary
The Federal Aviation Administration (FAA) proposes to adopt a new airworthiness directive (AD) that is applicable to Hartzell Propeller Inc. HD-E6C-3B/E13890K propellers. This proposal would require the reduction of the original hub certified service (fatigue) life from unlimited hours to 37,400 flight hours. This proposal is prompted by a reevaluation by Hartzell Propeller Inc. of the D-5108-( ) original hub service life certification calculations. The actions specified by the proposed AD are intended to prevent fatigue failure of D-5108-( ) hubs, which may result in loss of airplane control.