69-14-02 VICKERS VISCOUNT: Amdt. 39-792. Applies to Viscount Model 745D and 810 Series Aircraft.
Compliance required as indicated unless already accomplished.
To prevent fatigue damage to the inner section and center section lower wing spar booms accomplish the following:
(a) Replace the center section lower spar boom and the inner section lower spar boom with new booms of the same part number before they have exceeded 90 percent of the approved retirement time specified in the last applicable Viscount Instruction Manual, Chapter 3, Overhaul Schedule Section, dated before April 1, 1969, or within the next 250 landings whichever occurs later, after the effective date of this AD.
(b) All new center section and inner section lower wing spar booms that are installed in accordance with the requirements of paragraph (a) of this AD must be replaced before the accumulation of the revised retirement times as specified in the latest amendment to the Viscount Instruction Manual, Chapter 3, Overhaul Schedule Section, dated after April 1, 1969.
(c) For the purpose of complying with this AD, subject to acceptance by the assigned FAA maintenance inspector, the number of landings may be determined by dividing each airplane's hours' time in service by the operator's fleet average time from takeoff to landing for the airplane type.
This amendment becomes effective July 7, 1969.