68-19-03 BRITISH AIRCRAFT: Amendment 39-655. Applies to Viscount Model 810 Series airplanes.
Compliance required within the next 125 landings after the effective date of this AD, or before the accumulation of 10,125 landings, whichever occurs later.
To prevent cracking or distortion of forward landing flap assembly diaphragms P/Ns 80284-139/140, 80284-561/562, and 80284-711/712, and attachment plates P/N's 80284-131, 80284-565 and 80284-709, accomplish the following:
(a) Replace the No. 1 forward landing flap assembly diaphragm P/Ns 80284-139 and 80284-140 with new landing flap assembly diaphragm P/Ns 81084-51 and 81084-52 in accordance with British Aircraft Corporation Modification Bulletin No. FG.2089, dated January 12, 1968 or later ARB-approved issue, or an equivalent approved by the Chief, Aircraft Certification Staff, FAA, Europe, Africa, and Middle East Region.
(b) Visually inspect Nos. 2 and 3 forward landing flap assembly diaphragms and attachment plates for cracks in accordance with British Aircraft Corporation Preliminary Technical Leaflet No. 136, Issue 1 (800/810 Series) or later ARB-approved issue, or an FAA- approved equivalent. Repeat this inspection at intervals not to exceed 600 landings from the last inspection until the accumulation of 20,000 landings and thereafter at intervals not to exceed 450 landings from the last inspection.
(c) If cracks are detected during the inspection required by paragraph (b), before the next flight, replace the defective parts with serviceable parts of the same part number. Continue the repetitive inspections required by paragraph (b) for all replacement parts.
(d) 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 October12, 1968.