AD 76-26-02

76-26-02 BOEING: Amendment 39-2795 as amended by Amendment 39-2836. Applies to all Model 737 series airplanes certificated in all categories. Compliance required as indicated. To detect cracks in the forward and aft cargo door lower stop fittings, (4 total) accomplish the following: A. Upon accumulation of 15,000 flights or within the next 500 flights from the effective date of this AD, whichever occurs later, inspect the aft cargo door lowest side stop fittings per paragraph C. B. Upon accumulation of 20,000 flights or within the next 500 flights from the effective date of this AD, whichever occurs later, inspect the forward cargo door lowest side stop fittings per paragraph C. C. Visually or eddy current inspect the lowest side stop fittings in accordance with Boeing Service Bulletin No. 737-52-1065, or later FAA approved revisions, or in a manner approved by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region. Repeat the inspections at intervals not to exceed 500 flights from the last inspection for the visual method and 2,500 flights from the last inspection for the eddy current method. D. If a cracked fitting is detected: 1. replace the fitting and visually or eddy current inspect the adjacent fitting prior to further flight in accordance with Boeing Service Bulletin No. 737-52-1065, or later FAA approved revisions, or in a manner approved by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region; or, 2. continue service with no more than one cracked fitting for up to 50 flights under the following conditions: a. assure the stop fittings adjacent to the cracked fitting are crack-free by visual or eddy current inspection specified in the service bulletin. b. within 25 flights repeat the visual or eddy current inspection of the adjacent fitting. c. within 50 flights replace the fitting in accordance with the service bulletin. E. Replacement fittings which are not terminating actionparts per paragraph F of this AD must be inspected per paragraphs A, B, and C of this AD as appropriate, except that the initial inspection threshold may be increased to 30,000 flights on the forward cargo door stop fittings and 25,000 flights on the aft cargo door stop fittings, if the fittings are shot peened prior to initial installation per Figure 3 of Boeing Service Bulletin No. 737-52-1065, or later FAA approved revisions, or in a manner approved by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region. F. Installation of a new improved fitting listed in Boeing Service Bulletin No. 737-52-1065, Revision 1, or later FAA approved revisions or an equivalent approved by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region, constitutes terminating action for this AD at that fitting. G. For the purpose of this AD, when conclusive records are not available to show the number of flights accumulated by a particular fitting, the number of flights maybe computed by dividing the airplane time-in-service since the fitting was installed in the airplane by the operator's fleet average time per flight for his Model 737 airplanes. H. Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA Northwest Region, may adjust the repetitive inspection intervals in this AD, if the request contains substantiating data to justify the increase for that operator. The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive, who have not already received these documents from the manufacturer, may obtain copies upon request to Boeing Commercial Airplane Company, P. O. Box 3707, Seattle, Washington 98124. The documents may also be examined at FAA Northwest Region, 9010 East Marginal Way South, Seattle, Washington.Amendment 39-2795 became effective January 14, 1977. This amendment 39-2836 becomes effective March 2, 1977.