AD 73-09-04

73-09-04 BOEING: Amendment 39-1627 as amended by Amendment 39-1643 is further amended by Amendment 39-1822. Applies to all Model 707, 727 and 737 series airplanes certificated in all categories, listed in Boeing Service Bulletins 3105, Revision 1, dated June 15, 1973 (707); 727-52-83, Revision 1, dated June 20, 1973; and 737-52-1044, Revision 1, dated June 15, 1973, respectively, or later FAA approved revisions. Compliance required as indicated. To detect failures or cracks in the forward entry door upper spigot, accomplish the following: (a) All aircraft which have accumulated 8000 landing cycles on the effective date of this AD and have bushings installed on the upper spigot, inspect per paragraph (1) and (2) below: (1) Within the next 500 landings after the effective date of this AD, perform a visual inspection of the spigot tab for failure and displacement by inserting a .010 to .020 thick feeler gage in the gap between the upper hinge assembly upper link and guideplate bushing. If the gage can be passed through the area, the spigot tab has separated from the spigot, and the spigot must be either replaced or modified per (b) below, prior to further flight. (2) Within the next 2500 landings after the initial inspection per (a)(1) above, unless already accomplished within the last 3000 landings, and thereafter at intervals not to exceed 3000 landings since the last inspection, perform an X-ray inspection of the spigot in the area of the spigot tab for evidence of cracking. The X-ray inspection is to be in accordance with the Boeing Service Bulletins noted in paragraph (b)(2) below. Spigots with failed tabs must be either replaced or modified per (b) below, prior to further flight. (b) Modifications per paragraphs (2)(3) or (4) below are considered terminating action. (1) Replace the spigot with a new or serviceable part and re-enter the inspection program at the 8000 landing cycle per (a) above, or (2) Insert steel shot into the upper spigot tab grease cavity in accordance with the following Boeing Service Bulletins or their later FAA-approved revisions: 3105, dated December 11, 1972 (707 Model); 727-52-83 dated December 12, 1972; 737-52-1044 dated December 6, 1972; or (3) remove the guide arm upper link, in accordance with the appropriate Service Bulletins or their later FAA-approved revisions referred to in paragraph (2) above, or (4) make such other modification as is approved by the Chief, Engineering & Manufacturing Branch, FAA, Northwest Region. (c) Aircraft may be ferried to a base for maintenance per Sections 21.197 and 21.199 of the Federal Aviation Regulations. (d) For the purpose of this AD, when conclusive records are not available to show the number of landings accumulated by a particular spigot, the number of landings may be computed by dividing the airplane time in service since the spigot was installed in the airplane by the operators' fleet average time per flight for his airplanes of each model (707, 727-100 or 737). (e) Inspections prescribed by this AD do not apply to new replacement spigots of an improved design approved by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region. Amendment 39-1643 supersedes Amendment 39-1627 and became effective May 23, 1973. This Amendment 39-1822 becomes effective thirty (30) days after publication in the Federal Register.