MD Helicopters: Main Rotor Lower Hub Assembly

The FAA is adopting a new airworthiness directive (AD) to supersede an existing airworthiness directive for MD Helicopters, Inc. (MDHI), Model MD900 helicopters. The existing AD requires a visual inspection, and if necessary, an eddy current inspection of the main rotor lower hub assembly (lower hub) for a crack.

If a crack exists, the AD requires replacing the lower hub with an airworthy lower hub before further flight. Because that AD was immediately effective, the FAA declined to require certain long-term actions prior to public comment. This superseding AD will require the same inspections as the existing AD but will also require long-term recurring inspections and replacing the lower hub with an airworthy lower hub.

The FAA is issuing this AD to detect a crack in the lower hub and prevent failure of the lower hub and subsequent loss of control of the helicopter.

Posted on Tuesday, October 23, 2012 (Archive on Monday, January 1, 0001)
Posted by NStaff  Contributed by