77-15-15 BRITISH AIRCRAFT CORPORATION: Amendment 39-2986. Applies to BAC 1- 11 200 and 400 series airplanes, certificated in all categories.
Compliance is required within the next 200 hours time in service after the effective date of this AD, unless already accomplished.
To prevent the inadvertent loss of cabin pressure due to failure of the light alloy stop on the cabin pressure discharge valve manual control, replace the light alloy stop, P/N AB55-2301, on the gear wheel and drum assembly of the air conditioning discharge valve manual control (P/N AB55A-2425 or ED55A779) with an improved strength stop, P/N AB55-3433, or an FAA-approved equivalent.
(British Aircraft Corporation Service Bulletin No. 21-PM 5139, Revision 2, dated September 5, 1973, applies to this same subject.)
This amendment becomes effective August 29, 1977.