Airworthiness Directives; Air Tractor, Inc. Models AT-602, AT-802, and AT-802A Airplanes

We are adopting a new airworthiness directive (AD) that supersedes AD 2006-22-08, which applies to all Air Tractor, Inc. (Air Tractor) Models AT-602, AT-802, and AT-802A airplanes. AD 2006-22-08 currently requires you to repetitively inspect the engine mount for any cracks, repair or replace any cracked engine mount, and report any cracks found to the FAA. Since we issued AD 2006-22-08, the FAA has received reports of two Model AT- 802A airplanes with cracked engine mounts below the initial compliance time in AD 2006-22-08. The FAA has determined that an initial inspection is required when the airplane reaches a total of 1,300 hours time-in-service (TIS) instead of 4,000 hours TIS required by AD 2006- 22-08. Consequently, this AD retains the actions of AD 2006-22-08 while requiring the initial inspection when the airplane reaches a total of 1,300 hours TIS. We are issuing this AD to detect and correct cracks in the engine mount, which could result in failure of the engine mount. Such failure could lead to separation of the engine from the airplane.