Airworthiness Directives; Boeing Model 747-100B SUD, -200B, -200C, -200F, and -300 Series Airplanes
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.
Airworthiness Directives; Precise Flight, Inc. Models SVS I and SVS IA Standby Vacuum Systems
The FAA proposes to adopt a new airworthiness directive (AD) for all airplanes equipped with Precise Flight, Inc. (Precise Flight) Models SVS I and SVS IA standby vacuum systems (SVS) installed under certain supplemental type certificates or through field approval. This proposed AD would require you to replace the airplane flight manual supplement (AFMS) in the airplane flight manual with the appropriate revision and install placards as defined in the AFMS, upgrade the Model SVS I or SVS IA SVS to the Model VI SVS, and add the instructions for continued airworthiness (ICA) to the maintenance schedule for the aircraft. This proposed AD results from several reports of failed shuttle control valves of the standby vacuum system (SVS) and one report of an airplane crash with a fatality in which improper use of the SVS was a factor. We are issuing this proposed AD to correct problems with the SVS before failure or malfunction during instrument flight rules (IFR) flight that can lead to pilot disorientation and loss of control of the aircraft.
Airworthiness Directives; Air Tractor, Inc. Models AT-300, AT-301, AT-302, AT-400, AT-400A, AT-401, AT-402, AT-602, AT-802, and AT-802A Airplanes
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.
Airworthiness Directives; General Electric Company (GE) CF6-80C2 Turbofan Engines; Correction
This document makes a correction to Airworthiness Directive (AD) 2004-22-07. That AD applies to GE CF6-80C2 turbofan engines with certain part number (P/N) high pressure turbine stage 2 nozzle guide vanes (HPT S2 NGVs) installed. That AD was published in the Federal Register on October 27, 2004 (69 FR 62571). The phrase ``5.0 or more cycles per flight leg'' in the Compliance section is incorrect. This document corrects that phrase. In all other respects, the original document remains the same.