AD 70-22-06

70-22-06 BOEING: Amdt 39-1100. Applies to Model 747 Series Airplanes.

Compliance required as indicated.

To prevent fuel leakage and possible engine fire due to a damaged or misaligned engine cowl fluid drain bellows seal, accomplish the following:

(a) Within the next 100 hours' time in service after the effective date of this AD, unless the seal modification in accordance with (b) or (c), below, have been previously accomplished, inspect the bellows seal on the gang drain assembly each time the engine cowl doors are closed to insure proper seal installation and seating on the drain duct in accordance with the inspection instructions in Boeing Service Bulletin 71-2018, Revision 2, dated June 18, 1970, or later FAA approved revision or an equivalent method approved by the Chief, Aircraft Engineering Division, FAA Western Region.

(b) Within the next 300 hours' time in service after the effective date of this AD, unless previously accomplished, inspect the aft fueldrain duct for proper alignment with the turbine case and combustion chamber drains and modify the engine fluid drain bellows seal in accordance with Boeing Service Bulletin 71-2018, Revision 2, dated June 18, 1970, or later FAA approved revision or an equivalent method approved by the Chief, Aircraft Engineering Division, FAA Western Region.

(c) Within the next 1500 hours' time in service after the effective date of this AD, unless already accomplished, modify the engine gang drain bellows seal in accordance with Boeing Service Bulletin 71-2030, dated October 16, 1970, or later FAA approved revision or an equivalent method approved by the Chief, Aircraft Engineering Division, FAA Western Region.

(d) Upon completion of the work described in (c), the inspection and modification requirements of (a) and (b) are no longer applicable.

This amendment becomes effective on November 3, 1970.