83-19-05 BRITISH AEROSPACE: Amendment 39-4733. Applies to Model BAC 1-11 200 and 400 series airplanes, certificated in all categories. To prevent loss of rear spar frame integrity due to cracks on the rear spar web of the center section torque box, accomplish the following, unless already accomplished:
A. Prior to the accumulation of 30,000 landings or within the next 200 landings, whichever occurs later, after the effective date of this AD, inspect the rear spar frame, and repair if necessary, in accordance with paragraph 2, Accomplishment Instructions, of British Aerospace Alert Service Bulletin No. 53-A-PM5837, Issue 1, dated April 21, 1982.
B. Repeat the inspection of paragraph A., above, at intervals not to exceed:
(1) 3,600 landings for aircraft with less than 45,000 landings at the last inspection and
(2) 1,800 landings for aircraft with more than 45,000 landings at the last inspection.
C. Alternate means of compliance which provide an equivalent level of safety may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region.
D. 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 and/or modifications required by this AD.
This amendment becomes effective October 6, 1983.