AD 78-11-07

78-11-07 BOEING: Amendment 39-3228 as amended by Amendment 39-3268. Applies to Boeing Model 727 series airplanes, certificated in all categories, with horizontal stabilizer jackscrew gimbal support fittings, P/Ns 65-17435-3 and -4. Compliance required as indicated. To detect cracks in the horizontal stabilizer jackscrew gimbal support fittings, accomplish the following:

A. Within the next 750 flight hours time-in-service after the effective date of this AD or prior to November 15, 1978, whichever occurs first, unless accomplished within the last 750 flight hours time-in-service or since January 15, 1978, inspect the horizontal stabilizer jackscrew gimbal support fittings for cracking in accordance with paragraph B of this AD. Reinspect per paragraph C of this AD. B. 1. Inspect the two (2) lugs of the horizontal stabilizer jackscrew gimbal support fittings, P/N 65-17435-3(LH) and -4(RH), (4 lugs total), which attach to the jackscrew support arms, in accordance with one ofthe following: a. Eddy current inspection, with the jackscrew support arms removed, as specified in Boeing Alert Service Bulletin No. 727-55-A73, or later FAA approved revisions, or b. Low frequency eddy current inspection, with the jackscrew support arms installed, as specified in Boeing Alert Service Bulletin No. 727-55-A73, or later FAA approved revisions, or c. A procedure approved by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region. 2. Visually inspect the remaining exposed portions of the fittings not applicable to paragraph B.1 above. C. Repeat the inspections per paragraph B of this AD at intervals of either 1 or 2 below, as applicable: 1. 1,500 flight hours time-in-service or nine (9) months from the last inspection whichever occurs first, or 2. 3,000 flight hours time-in-service or eighteen (18) months from the last inspection, whichever occurs first, if the fittings have been reworked in accordance with Boeing Alert ServiceBulletin No. 727-55-A73, or later FAA approved revisions, or in a manner approved by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region. D. Cracked parts are to be replaced or repaired prior to further flight in accordance with Boeing Alert Service Bulletin No. 727-55-A73, or later FAA approved revisions, or in a manner approved by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region. E. Terminating action of this AD consists of replacement of the horizontal stabilizer jackscrew gimbal support fittings (2) with 7075-T73 aluminum alloy material fittings, Boeing P/N 65-17435-5/-6, or equivalent approved by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region. F. Airplanes may be flown to a maintenance base for repairs or replacement in accordance with FAR 21.197, subject to prior approval by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region. G. Requests for adjustments of the inspection threshold and intervals in this AD should be made directly to the Chief, Engineering and Manufacturing Branch, FAA Northwest Region. Such requests should contain substantiating data to justify the increase. All persons affected by this directive who have not already received the service bulletin from the manufacturer, may obtain copies upon request to Boeing Commercial Airplane Company, P.O. Box 3707, Seattle, Washington 98124. The documents may also be examined at FAA Northwest Region, 9010 East Marginal Way South, Seattle, Washington 98108.

Amendment 39-3228 became effective July 5, 1978. This amendment 39-3268 becomes effective August 16, 1978.