77-14-12 BRITISH AIRCRAFT CORPORATION: Amendment 39-2967. Applies to Model BAC 1-11, 200 and 400 series airplanes, certificated in all categories.
Compliance is required within the next 500 hours time in service after the effective date of this AD, unless already accomplished.
To prevent possible leaks in the ring main ducts of the passenger oxygen system, accomplish the following:
(a) Gain access to and conduct a one-time inspection of the passenger oxygen ring main ducts in accordance with paragraph 2.1.1. of the "Accomplishment Instructions" of British Aircraft Corporation Alert Service Bulletin 35-A-PM 5124, Issue No. 1, dated February 12, 1973, or an FAA-approved equivalent.
(b) If during the inspection required by paragraph (a) of this AD, chafing of any of the oxygen ducts is found or the clearance with adjacent structure is less than 0.050 inches, comply with the applicable provisions specified in paragraph 2.1.2, 2.1.3, 2.1.4, or 2.1.5 of BAC Alert Service Bulletin 35-A-PM 5124, dated February 12, 1973, or an FAA-approved equivalent.
(c) If, as a result of any of the actions required by paragraph (b) of this AD, the use of the passenger oxygen system is restricted, install an FAA-approved placard in full view of the pilot which defines the restriction and states that flight operations must be limited to those allowed by the applicable operating rules for the particular airplane.
This amendment becomes effective August 15, 1977.