Airworthiness Directive · Amendment 39-12711 · Bell Helicopter Textron Canada Model 407 Helicopters
Bell Helicopter Textron Canada Model 407 Helicopters
Superseded. A later AD replaced this one: AD 2004-10-07. Comply with the one in force.
Model 407 helicopters, with oil cooler blower bearing, part number (P/N) 406-040-339-ALL, 407-340-339-101 or -103, installed, certificated in any category.
This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2002-06-52, which was sent previously to all known U.S. owners and operators of Bell Helicopter Textron Canada (BHTC) Model 407 helicopters by individual letters. This AD requires a one-time replacement of certain bearings and, before further flight, adding a limitation and caution to the rotorcraft flight manual (RFM) and at specified intervals, inspecting, replacing, and lubricating certain oil cooler blower bearings. This AD is prompted by several occurrences of failure of an oil cooler blower bearing. The actions specified by this AD are intended to prevent failure of an oil cooler blower bearing, loss of tail rotor drive, and a subsequent forced landing.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
