80-26-01 ROCKWELL INTERNATIONAL: Amendment 39-3988. Applies to Model NA265-40 Series, Serial numbers 282-1 through 282-137, and -60 Series, Serial Numbers 306-1 through 306-64, 306-68, 306-71 through 306-103 airplanes certificated in all categories, not modified in accordance with Life Extension Modification per North American Rockwell Drawing 306-053010 or Service Kit SK 13808-40.
Compliance required as indicated, unless already accomplished.
To prevent inadvertent cabin depressurization accomplish the following:
(a) On aircraft with 2,000 or more hours' total time in service, within the next 600 hours' additional time in service or within the next 12 months from the effective date of this AD, whichever occurs first.
(1) Gain access and conduct a close visual inspection of the fuselage structure below the cabin entrance door and adjacent areas in accordance with "Modification Instructions 1 through 3" of Sabreliner Service Bulletin No. 56 dated September 22, 1980. Access is gained by modification in accordance with Service Kit SK 13808-10.
(2) If no cracks are detected, repeat the inspections required in paragraph (a)(1) of this AD at intervals not to exceed 600 hours' time in service since the last such inspection.
(3) If cracks are detected which are less than one inch long in the outboard bays only, repair per Sabreliner Service Bulletin Repeat the inspections required by paragraph (a)(1) of this AD at intervals not to exceed 600 hours' time in service since the last such inspection.
(4) If cracks are detected which are less than one inch long in the inboard bays or inboard and outboard bays, repair per Sabreliner Service Bulletin No. 56, dated September 22, 1980, and accomplish Service Kit SK 13808-30. Repeat the inspections required by paragraph (a)(1) of this AD at intervals not to exceed 600 hours' time in service since the last such inspection.
(5) If cracks are detected which are one inch or longer, repairin a manner approved by the Chief, Engineering and Manufacturing Branch, FAA Western Region, or by the installation of Service Kit SK 13808-40. The installation of Service Kit SK 13808-40 terminates the inspections required by this AD. For other repairs, unless specifically authorized by the Chief, Engineering and Manufacturing Branch, FAA Western Region, repeat the inspections required by paragraph (a)(1) of this AD at intervals not to exceed 600 hours' time in service since the last such inspection.
(b) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of inspections required by this AD.
(c) Alternative inspections, modifications or other actions which provide an equivalent level of safety may be used when approved by the Chief, Engineering and Manufacturing Branch, FAA Western Region.
This amendment becomes effective January 19, 1981.