Airworthiness Directive · Amendment 39-13995 · Boeing Model 747-100B SUD, -200B, -200C, -200F, and -300 Series Airplanes
Boeing Model 747-100B SUD, -200B, -200C, -200F, and -300 Series Airplanes
Superseded. A later AD replaced this one: AD 2005-08-01. Comply with the one in force.
This AD applies to Boeing Model 747-100B SUD, -200C, -200F, and -300 series airplanes, line numbers 1 through 685 inclusive; and Boeing Model 747-200B series airplanes, line numbers 271, 276, 336, 344, 369, 389, 397, 474, 491, 518, 521, and 539; certificated in any category.
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.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Before the accumulation of 8,000 total flight cycles, or within 10 flight cycles after the effective date of this AD, whichever occurs later, do an external detailed inspection for cracked skin or loose or missing fasteners of the body skin between BS 420 and 460 inclusive and between stringers S-8 and S-12 inclusive on the left and right sides of the airplane. Repeat the external detailed inspection thereafter at intervals not to exceed 25 flight cycles.
Note 1: For the purposes of this AD, a detailed inspection is: “An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.”
If any cracked skin or loose or missing fastener is detected during any external detailed inspection required by paragraph (f) of this AD, before further flight, do a surface high frequency eddy current (HFEC) inspection for cracks in the frames at BS 420, 440, and 460 between stringers S-8 and S-12 on the left and right sides of the airplane, in accordance with paragraph 2. and Notes 2 and 3 of Figure 17 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2265, Revision 9, dated February 17, 2005, except as provided by Note 1 of Figure 17 of the service bulletin. Accomplishing the surface HFEC inspection ends the repetitive inspections required by paragraph (f) of this AD.
(1) If no cracked frame is found, before further flight, repair the cracked skin and replace the loose or missing fasteners with new fasteners, as applicable, in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or in accordance with data meeting the certification basis of the airplane approved by an Authorized Representative (AR) for the Boeing Delegation Option Authorization (DOA) Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically reference this AD.
(2) If any cracked frame is found, before further flight, repair the cracked frame and skin and replace the loose or missing fasteners with new fasteners, as applicable, in accordance with a method approved by the Manager, Seattle ACO, FAA; or in accordance with data meeting the certification basis of the airplane approved by an AR for the Boeing DOA Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically reference this AD.
Modification in Zone 2 in accordance with Boeing Service Bulletin 747-53-2272, dated January 12, 1987, through Revision 18, dated May 16, 2002, constitutes terminating action for the requirements of this AD.
Note 2: Paragraph H. of AD 91-11-01, amendment 39-6997 refers to Boeing Service Bulletin 747-53-2272, dated January 12, 1987, as the appropriate source of service information for accomplishing the optional terminating action in that AD. AD 90-06-06, amendment 39-6490, refers to Boeing Service Bulletin 747-53-2272, Revision 12, dated December 22, 1988; or earlier revisions; as an appropriate source of service information for accomplishing the mandatory terminating action in that AD.
