AD 2002-06-52 Amendment 39-12711

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.