Airworthiness Directive · Amendment 39-13997 · Boeing Model 747-100B SUD, -300, -400, and -400D Series Airplanes
Boeing Model 747-100B SUD, -300, -400, and -400D Series Airplanes
This AD applies to Model 747-100B SUD, -300, -400, and -400D series airplanes; certificated in any category; as identified in Boeing Special Attention Service Bulletin 747-53-2483, Revision 1, dated August 28, 2003.
The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 747-100B SUD, -300, -400, and -400D series airplanes. This AD requires a one-time inspection for discrepancies of the fuselage frame to tension tie joints at body stations (BS) 1120 through 1220 and to determine if steel splice plates are installed on the fuselage frames, and related investigative and corrective actions. This AD is prompted by reports indicating that severed tension ties were found at the fuselage frame joints at BS 1120 and 1140. We are issuing this AD to prevent fatigue cracking of the fuselage frame to tension tie joints, which could result in severing of the tension ties and consequent rapid decompression of the airplane fuselage.
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 4,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever is later: Perform a detailed inspection for discrepancies of the fuselage frame to tension tie joints at BS 1120 through BS 1220, and to determine if steel splice plates are installed on the fuselage frames. Do the inspection in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 747-53-2483, Revision 1, dated August 28, 2003. Do any applicable investigative and corrective actions before further flight in accordance with the service bulletin, except as provided by paragraph (h) of this AD.
Note 1: For the purposes of this AD, a detailed inspection is: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”
For the purposes of calculating the compliance threshold for the actions required by paragraph (f) of this AD, all pressurized flight cycles, including the number of flight cycles in which cabin differential pressure is at 2.0 pounds per square inch (psi) or less, must be counted when determining the number of flight cycles that have occurred on the airplane. Where the service bulletin and this AD differ, the AD prevails.
For any repairs outside the limits of Boeing Special Attention Service Bulletin 747-53-2483, Revision 1, dated August 28, 2003, or if any aluminum splice plate is installed on the fuselage frames: Before further flight, repair or replace, 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 for the Boeing Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair or replacement method to be approved, as required by this paragraph, the approval must specifically refer to this AD.
(i) Inspections and corrective actions accomplished before the effective date of this AD in accordance with Boeing Special Attention Service Bulletin 747-53-2483, dated October 24, 2002, are considered acceptable for compliance with the corresponding actions specified in this AD.
Although the Accomplishment Instructions of Boeing Special Attention Service Bulletin 747-53-2483, Revision 1, dated August 28, 2003; describe procedures for submitting certain information to the manufacturer, this AD does not require that action.
