AD 83-08-02

83-08-02 BOEING: Amendment 39-4634. Applies to Model 747 series airplanes certificated in all categories listed in Boeing Service Bulletin 747-57-2206, Revision 1, and Service Bulletin 747-57-2217, Revision 1, or later FAA approved revisions. The effectivity is divided into eight groups for Service Bulletin 747-57-2206-R1 and three groups for Service Bulletin 747-57-2217- R1, listed in the service bulletins. To prevent trailing edge flap track fuse bolt failures, accomplish the following:

A. Within 400 landings after the effective date of this AD, unless accomplished within the last 1600 landings, and at intervals thereafter not to exceed 2000 landings until the replacement called for in paragraphs B. or C. is accomplished, visually inspect the bolts listed in Table I, below, for deformation and failure. Bolts found deformed or failed must be replaced in accordance with paragraph B. or C., as applicable, prior to further flight. Bolts found acceptable for service are to beretorqued in accordance with Table I prior to further flight.

B. Unless previously accomplished, replace forward fuse bolts on flap tracks No. 1, 2, 3, 6, 7, and 8 with redesigned bolts in accordance with Figures 1, 3, and 5 of Boeing Service Bulletin 747-57-2206-R1, or later FAA approved revision, within 200 landings after the effective date of this AD, or prior to the accumulation of the thresholds listed in Table 1, 3, and 4, Section III, of the above Boeing Service Bulletin whichever is later. Installation of these bolts constitutes terminating action for these tracks.

C. Unless previously accomplished, replace on flap tracks No. 2, 4, 5, and 7, forward fuse bolts listed in Table I & II of Boeing Service Bulletin 747-57-2217-R1 or later FAA approved revisions, in accordance with Figures 2 and 3 of the bulletin within 200 landings after the effective date of this AD, or prior to the accumulation of 25,000 landings, whichever is later. Installation of these bolts constitutes terminating action for these tracks.

D. For purposes 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 from takeoff to landing for the airplane type.

E. Alternate means of compliance with the AD which provide an equivalent level of safety may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region.

F. Aircraft may be ferried to a base for maintenance in accordance with Sections 21.197 and 21.199 of the Federal Aviation Regulations.

G. This AD supersedes AD 78-25-06.

TABLE I

Flap Inspect & Retorque In Accordance Airplane

1 & 8 Fig. 2 S/B 57-2206-R1 See Table I Section III of S/B 57-2206-R1 I-IV, VII, & VIII As defined by S/B 57-2206-R1 2 & 7 Fig. 1 S/B 57-2217-R1 See Table I of S/B 57-2217-R1 III As defined by S/B57-2217-R1 4 & 5 Fig. 4 S/B 57-2217-R1 See Table II of S/B 57-2217-R1 I, II, & III As defined by S/B 57-2217-R1

NOTE: Later FAA approved revisions of the above service bulletins may be used. All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Boeing Commercial Airplane Company, P.O. Box 3707, Seattle, Washington 98124. These documents may also be examined at FAA, Northwest Mountain Region, 9010 East Marginal Way South, Seattle, Washington.

This amendment becomes effective May 31, 1983.