Summary
This document proposes to revise an existing airworthiness directive (AD), applicable to MT-Propeller Entwicklung GMBH Model MTV- 3-B-C propellers, that currently requires initial and repetitive dye penetrant or eddy current inspections for cracks in the propeller hub, and rework of the propeller hub or replacement with a new model propeller hub. This action would allow the repetitive dye penetrant inspections to be performed on-wing as opposed to at approved propeller repair stations, and to mark B-050 propeller hubs that have been modified in accordance with the current AD or this revision. This proposal is prompted by issuance of a revised service bulletin that describes procedures for on-wing inspections. The actions specified by the proposed AD are intended to prevent propeller hub cracks, which could result in propeller blade separation and possible loss of control of the aircraft.