AD 92-06-14

92-06-14 BOEING: Amendment 39-8194. Docket No. 91-NM-190-AD.

Applicability: Model 727 series airplanes, listed in Boeing Service Bulletin 727-53-0126, Revision 6, dated December 21, 1989, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent failure of the body station (BS) 950 side fitting and subsequent depressurization of the airplane, accomplish the following:

(a) Prior to the accumulation of 15,000 total flight cycles or within the next 3,000 flight cycles or 18 months after the effective date of this AD, whichever occurs later, conduct visual, eddy current, and ultrasonic inspections of the body station (BS) 950 side fitting between stringers S-9 and S-13 for cracks and web separations, in accordance with Figure 1 of Boeing Service Bulletin 727-53-0196, dated February 14, 1991. Step 5 of Figure 1 of the service bulletin (which refers to dye penetrant inspections); and Steps 8, 9, 10, and 11 of Figure 1 of the service bulletin (which refer to the removal of weather caulking and inspection of the fitting through the gap between the skins); are not required to be accomplished.

(b) If cracks or separations are found, prior to further flight, repair the body station (BS) 950 side fitting in accordance with Boeing Service Bulletin 727-53-0196, dated February 14, 1991; or Boeing Service Bulletin 727-53-0126, Revision 6, dated December 21, 1989. After repairs, conduct repetitive inspections as follows:

(1) For airplanes on which outboard flange cracks are removed by oversizing the fastener holes, repeat the inspections required by paragraph (a) of this AD at intervals not to exceed 6,000 flight cycles or 3 years, whichever occurs first.

(2) For airplanes on which the external doubler is used to repair only outboard flange cracks, repeat the inspections required by paragraph (a) of this AD at intervals not to exceed 6,000 flight cycles or 3 years, whichever occurs first.(3) For airplanes on which the external doubler is used to repair either web separations or web separations and outboard flange cracks, repeat the inspections required by paragraph (a) at intervals not to exceed 3,000 flight cycles or 18 months, whichever occurs first.

(4) For airplanes on which the external doubler and the internal angles are used for repair, conduct an x-ray inspection of the repaired area to detect crack growth at intervals not to exceed 12,000 flight cycles or 6 years, whichever occurs first, in accordance with Boeing Service Bulletin 727-53-0126, Revision 6, dated December 21, 1989.

(c) If no cracks or separations are found, and uncracked fastener holes have been reworked in accordance with Figure 1 of Boeing Service Bulletin 727-53-0196, dated February 14, 1991, repeat the inspection requirements of paragraph (a) of this AD at intervals not to exceed 6,000 flight cycles or three years, whichever occurs first.

(d) If no cracks or separationsare found and uncracked fastener holes have not been reworked in accordance with Figure 1 of Boeing Service Bulletin 727-53-0196, dated February 14, 1991, repeat the inspection requirements of paragraph (a) of this AD at intervals not to exceed 3,000 flight cycles or 18 months, whichever occurs first.

(e) The partial replacement of the body station (BS) 950 side fitting in accordance with Boeing Service Bulletin 727-53-0196, dated February 14, 1991, constitutes terminating action for the inspection requirements of this AD for the replaced portion of the fitting. Unreplaced portions must continue to be inspected in accordance with this AD.

(f) The complete replacement of the body station (BS) 950 side fitting in accordance with Boeing Service Bulletin 727-53-0126, Revision 6, dated December 21, 1989, constitutes terminating action for the inspection requirements of this AD.

NOTE: Replacement of the side fitting in accordance with Boeing Service Bulletin 727-53-0126, Revision 4, dated October 16, 1986; or Revision 5, dated May 26, 1988; is considered in compliance with this paragraph.

(g) An alternative method of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Seattle ACO.

(h) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.

(i) The inspections, repairs, and replacements shall be done in accordance with Boeing Service Bulletin 727-53-0196, dated February 14, 1991; and Boeing Service Bulletin 727-53-0126, Revision 6, dated December 21, 1989; as applicable. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124. Copies may be inspected at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington; or at the Office of the Federal Register, 1100 L Street NW., Room 8401, Washington, DC.

(j) This amendment becomes effective on April 28, 1992.