Airworthiness Directive · Amendment 39-12975 · MD Helicopters, Inc. Model MD900 Helicopters
MD Helicopters, Inc. Model MD900 Helicopters
MD-900 helicopters, serial numbers 900-00008 through 900-00110, with a main rotor support static mast (mast), part number 900F2401021-101, installed, certificated in any category.
This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2002-22-51, which was sent previously to all known U.S. owners and operators of MD Helicopters, Inc. (MDHI) Model MD900 helicopters by individual letters. This AD requires, before further flight, certain procedures and inspections of the main rotor support static mast (mast) and the mast threads for any crack or pitting. If any crack or pitting is found, this AD requires removing the mast from service. The actions specified by this AD are intended to detect any crack or pitting in the mast that could result in failure of the mast, separation of the main rotor, and subsequent loss of control of the helicopter.
