Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Air Tractor, Inc. (Air Tractor) Models AT-300, AT-301, AT-302, AT-400, AT-400A, AT-401, AT-402, AT-602, AT-802, and AT-802A airplanes. This proposed AD would require you to repetitively tighten the four eyebolts that attach the front and rear spar of the horizontal stabilizer to the respective stabilizer strut to the specified torque, and repetitively replace at specified intervals any eyebolts that attach the front and rear spar of the horizontal stabilizer to the respective stabilizer strut. An option for replacing the steel brace assembly inside the stabilizer with a new steel brace assembly with larger bushings and stronger eyebolts that increases the interval for replacement of eyebolts for AT-602, AT-802, and AT-802A airplanes is also included in this proposed AD. This proposed AD results from reports of failures of the subject eyebolt. We are issuing this proposed AD to detect, correct, and preventfuture fatigue failure in any eyebolt that attaches the front and rear spar of the horizontal stabilizer to the respective stabilizer strut. Failure of the eyebolt could lead to an abrupt change or complete loss of pitch control and/or the airplane departing from controlled flight.