Airworthiness Directive · Amendment 39-14643 · Boeing Model 737-200C Series Airplanes
Boeing Model 737-200C Series Airplanes
This AD applies to all Boeing Model 737-200C series airplanes, certificated in any category.
The FAA is superseding an existing airworthiness directive (AD) which applies to all Boeing Model 737-200C series airplanes. That AD currently requires a one-time external detailed inspection for cracking of the fuselage skin in the lower lobe cargo compartment; repetitive internal detailed inspections for cracking of the frames in the lower lobe cargo compartment; repair of cracked parts; and terminating action for the repetitive internal detailed inspections. This new AD restates the requirements of the existing AD and adds a requirement to perform repetitive detailed inspections of the body station (BS) 360 and BS 500 fuselage frames, after accomplishing the terminating action, and repair if necessary. This AD results from multiple reports that the existing AD is not fully effective in preventing cracks in the BS 360 and BS 500 fuselage frames. We are issuing this AD to detect and correct cracking of the fuselage frames from BS 360 to BS 500B, which could lead to loss of the cargo door during flight and consequent rapid decompression 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.
Prior to the accumulation of 29,000 total flight cycles or within 250 flight cycles after August 9, 1993 (the effective date AD 93-13-02, amendment 39-8615, which was superseded by AD 99-12-08), whichever occurs later, accomplish an external detailed inspection to detect cracks of the fuselage skin between stringers 19 left and 25 left and at BS 360 to BS 540, in accordance with Boeing Alert Service Bulletin 737-53A1160, dated October 24, 1991; or Boeing Service Bulletin 737-53A1160, Revision 1, dated April 29, 1993. If any crack is found, prior to further flight, accomplish the requirements of paragraphs (f)(1) and (f)(2) of this AD.
(1) Perform an internal detailed inspection to detect cracks of the frames between stringers 19 left and 25 left and at BS 360 to BS 500B, in accordance with either service bulletin.
(2) Repair all cracks in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), Transport Airplane Directorate, FAA.
Within 3,000 flight cycles after completing the requirements of paragraph (f) of this AD, unless accomplished within the last 6,000 flight cycles prior to August 9, 1993, perform an internal detailed inspection to detect cracks of the frames between stringers 19 left and 25 left and at body stations 360 to 500B, in accordance with Boeing Alert Service Bulletin 737-53A1160, dated October 24, 1991; or Boeing Service Bulletin 737-53A1160, Revision 1, dated April 29, 1993. Thereafter, repeat the internal detailed inspection at intervals not to exceed 9,000 flight cycles. If any crack is found during any inspection required by this paragraph, before further flight, repair as specified in paragraph (g)(1) or (g)(2) of this AD, as applicable.
(1) If any crack is found that does not exceed the limits specified in the Boeing 737 Structural Repair Manual (SRM), repair the crack in accordance with a method approved by the Manager, Seattle ACO; or in accordance with the procedures specified in paragraph (k)(4) of this AD. The SRM is one approved source of information for accomplishing the requirements of this paragraph. Repeat the internal detailed inspection thereafter at intervals not to exceed 9,000 flight cycles.
(2) If any crack is found that exceeds the limits specified in the SRM, repair the crack in accordance with a method approved by the Manager, Seattle ACO; or in accordance with the procedures specified in paragraph (k)(4) of this AD. Repeat the internal detailed visual inspection thereafter at intervals not to exceed 9,000 flight cycles.
Prior to the accumulation of 75,000 total flight cycles, or within 3,000 flight cycles after July 16, 1999 (the effective date of AD 99-12-08), whichever occurs later, install doublers on the specified frames located between stringers 19 left and 25 left from BS 360 to BS 500B, in accordance with Boeing Service Bulletin 737-53A1160, Revision 1, dated April 29, 1993. Installing these doublers on the specified fuselage frames ends the repetitive inspections required by paragraphs (f) and (g) of this AD.
(i) Within 9,000 flight cycles after accomplishing the modification required by paragraph (h) of this AD, or within 4,500 flight cycles after the effective date of this AD, whichever occurs later, perform an internal detailed inspection to detect cracking in the fuselage frame at BS 360 and the fuselage frame at BS 500, between stringers 19 left and 25 left, in accordance with Boeing Alert Service Bulletin 737-53A1160, dated October 24, 1991; or Boeing Service Bulletin 737-53A1160, Revision 1, dated April 29, 1993. Thereafter, repeat the internal detailed inspection of the BS 360 and BS 500 frames at intervals not to exceed 9,000 flight cycles.
(j) If any crack is found during any inspection required by paragraph (i) of this AD, before further flight, repair the crack using a method approved in accordance with the procedures specified in paragraph (k) of this AD.
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.”
