Federal Aviation Administration March 4, 2005 – Federal Register Recent Federal Regulation Documents

This document publishes in the Federal Register an amendment adopting airworthiness directive (AD) 2005-04-51 that was sent previously to all known U.S. owners and operators of certain Boeing Model 747-100B SUD, -200B, -200C, -200F, and -300 series airplanes by individual notices. This AD requires repetitive external detailed inspections for cracked skin or loose or missing fasteners of the body skin between body stations (BS) 420 and 460 inclusive and between stringers S-8 and S-12 inclusive on the left and right sides of the airplane, and a high frequency eddy current inspection for cracked frames if necessary. This AD also requires repair of any cracked frame or skin, and replacement of any loose or missing fastener. This AD is prompted by reports of large cracks common to fuselage frames in the upper deck area and severed or nearly severed adjacent frames. We are issuing this AD to detect and correct fatigue cracks in the frames and body skin at BS 420, 440, and 460 between stringers S-8 and S-12 inclusive, which could lead to severed frames, and consequent rapid decompression and loss of the structural integrity of the airplane.

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 prevent future 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.