Airworthiness Directives; Air Tractor, Inc. Models AT-402, AT-402A, AT-402B, AT-602, AT-802, and AT-802A Airplanes

This amendment adopts a new airworthiness directive (AD) that applies to certain Air Tractor, Inc. (Air Tractor) Models AT-402, AT- 402A, AT-402B, AT-602, AT-802, and AT-802A airplanes. This AD requires you to repetitively inspect the upper longeron and upper diagonal tube on the left hand side of the aft fuselage structure for cracks and contact the manufacturer for a repair scheme if cracks are found. This AD is the result of reports of excessive movement in the empennage due to the loss of fuselage torsional rigidity. The actions specified by this proposed AD are intended to prevent failure of the fuselage caused by cracks. Such failure could result in loss of control of the airplane.