70-05-02 BRITISH AIRCRAFT CORPORATION: Amdt. 39-946. Applies to Viscount Models 744, 745D, and 810 series airplanes.
Compliance is required as indicated, unless already accomplished.
To prevent burn-through of aluminum piping, accomplish the following:
(a) For Viscount Models 744 and 745D airplanes, within the next 600 hours' time in service after the effective date of this AD replace the aluminum engine breather pipes located between the firewall and drains collector box with stainless steel pipes in accordance with British Aircraft Corporation Bulletin for Modification No. D.3226, dated March 17, 1969, or later ARB- approved issue or an FAA-approved equivalent.
(b) For Viscount Model 810 series airplanes, within the next 600 hours' time in service after the effective date of this AD, replace the aluminum engine breather pipes located between the firewall and drains collector box and the engine accessory gearbox aluminum breather pipe which connects into the engine breather piping, with stainless steel pipes in accordance with British Aircraft Corporation Bulletin for Modification No. FG.2102, dated March 17, 1969, or later ARB-approved issue or an FAA-approved equivalent.
This amendment becomes effective March 23, 1970.