68-04-03 BRITISH AIRCRAFT: Amendment 39-556. Applies to BAC 1-11 200 Series airplanes.
Compliance required as indicated.
To prevent fatigue damage to the Nose Undercarriage Retraction Jack Piston Head, P/N AB44-321, accomplish the following:
(a) Within the next 1,000 landings or before the accumulation of 10,000 landings, whichever occurs later, replace pre Modification PM 3069 piston heads, P/N AB44-321, with serviceable piston heads of the same part number or with BAC Modification PM 3069 piston heads. If pre Modification PM 3069 piston heads, P/N AB44-321 are used as replacements, replace the piston heads at intervals not to exceed 10,000 landings.
(b) The repetitive replacements required by paragraph (a) may be discontinued after the incorporation of BAC Modification PM 3069 piston heads.
(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 eachairplane's hours' time in service by the operator's fleet average time from takeoff to landing for the airplane type.
(BAC 1-11 Alert Service Bulletin 32-A-PM 3069 and BAC 1-11 Service Bulletin 32-PM 3069 cover this subject.)
This amendment becomes effective March 21, 1968.