AD 77-02-01

77-02-01 BOEING: Amendment 39-2812 as amended by Amendment 39-3012 is further amended by Amendment 39-3067. Applies to Model 707-300, -400, -300B, -300C series airplanes certificated in all categories listed in Boeing Service Bulletin No. (S.B.) 3168 with more than 5000 landings. Compliance required as indicated unless already accomplished. A. Within the next 250 landings, unless accomplished within the last 250 landings and at intervals thereafter not to exceed 500 landings, accomplish the following in accordance with Boeing Service Bulletin No. 3168, Revision 1, or later FAA approved revisions. (1) X-ray inspect the wing skin under the beavertail for cracks from the rear spar forward through stringer number 12 and the rear spar upper chord and the adjacent wing skin from W.S. 129 to W.S. 197. (2) Visually inspect the upper wing skin for cracks emanating from the fastener holes common to the rear spar upper chord from W.S. 117 to W.S. 197. (3) Visually inspect theaft edge of the upper wing skin under the doubler for cracks from BBL 70.5 to W.S. 117. (4) Ultrasonic inspect the upper wing skin for cracks at the four fastener holes common to the rear spar upper chord just outboard of BBL 70.5. (5) Wing skins and rear spar chords found cracked are to be repaired prior to further flight in accordance with Boeing Service Bulletin No. 2427 or Boeing Service Bulletin No. 2607, or in a manner approved by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region. Inspections are to continue until terminating action per paragraph F has been accomplished. B. Within the next 600 landings unless accomplished within the last 600 landings and at intervals thereafter not to exceed 1200 landings, accomplish the following: 1. Using low frequency eddy current or X-ray inspection techniques described in S.B. 3280, inspect the following areas for cracks: a. Rear spar upper chord and wing skin along the rear spar from wing station 197to 270. b. Wing skin and upper flange of the stringers from rear spar through stringer No. 12, outboard (only) of the beavertail at the stringer splice fasteners as described in S.B. 3280. c. Wing skin and upper flanges of stringer Nos. 10 and 11 at the right and left hand fuel filler cap fittings at W.S. 298 as described in S.B. 3280. 2. Wing skins, rear spar upper chords, stringers and stringer splices found cracked are to be repaired prior to further flight in accordance with S.B. 3280. Inspections are to continue until terminating action of paragraph F of this AD is accomplished. C. If rear spar and/or adjacent wing skin repairs or modifications interfere with any of the inspections of paragraph A or B of this AD, inspect for cracks in accordance with (1) and (2) below or in a manner approved by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region. (1) At the intervals specified in paragraph A or B of this AD (as appropriate to the area whererepairs interfere with the required inspections): a. Eddy current inspect the wing skin for cracks in the area adjacent to the repairs; or b. If internal steel doublers are installed on the horizontal leg of the rear spar upper chord, conduct a close visual inspection of the vertical leg of the rear spar upper chord for cracks emanating from the horizontal leg. When doublers on the rear spar vertical leg prohibit a close visual inspection, inspect the exposed lower edge of the vertical leg of the rear spar upper chord for new cracks. (2) At intervals not to exceed 4800 landings, visually inspect the exposed wing skin and exposed upper rear spar chord from inside and outside the wing. D. For aircraft having the fastener holes oversized in the fuel filler cap area per Boeing Service Bulletin 2892, the inspections of paragraph B.1.c. of this AD may be deferred until the accumulation of 8000 landings after the oversizing for 707-300C airplanes and 10,000 landings after oversizing for 707- 300, -400, -300B airplanes. E. For airplanes having the fastener holes oversized outboard, under and through the beavertail in accordance with Service Bulletin 2626, Revision 2, or later FAA approved revisions, the inspections of paragraph A.1 of this AD forward of the rear spar to stringer 12, may be deferred until the accumulation of 5000 landings after the oversizing for 707-300C series airplanes and 6000 landings after oversizing for 707-300, -400, 300B series airplanes. Also, the inspections of paragraph B.1.b. of this AD may be deferred until the accumulation of 12,000 landings after the oversizing for 707-300C series airplanes and 15,000 landings after oversizing for 707-300, -400, -300B series airplanes. F. Terminating action for this AD is: 1. Installation of a new wing skin and associated structure in accordance with S.B. 2607, Parts V or VI, or 2. Installation of external doublers in accordance with S.B. 2427, Part X(a) Drawing 65- 62721, andthe installation of the longer stringer splice angles at the fuel filler cap fittings in accordance with S.B. 2892, Revision 1. G. For airplanes with rear spar and/or upper wing skins already modified in accordance with S.B. 2427, Part X(a) Drawing 65-68302, or S.B. 2606, Revision 2, and 2626, Revision 2 and 2731, or similar repairs the threshold for the inspections of paragraph A, B.1.a., and B.1.b., of this AD may be deferred upon submittal of airplane serial number, specific applicable modification accomplished, number of flights when modification was made and current number of flights, to the Chief, Engineering and Manufacturing Branch, FAA Northwest Region. H. Upon request of the operator, an FAA Principal Maintenance Inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA Northwest Region, may adjust the repetitive inspection intervals in this AD, if the request contains substantiating data to justify the increase for that operator.I. Airplanes requiring repair or modification prior to the next flight may be flown in accordance with FAR 21.197 and 21.199 to a base where corrective action can be taken. The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). References herein to manufacturer's service bulletins are current at the time of issuance of this directive. In each instance where the directive requires compliance with one or more such service bulletins, the requirements of the directive may also be met by compliance with later FAA approved revisions of the applicable service bulletins, or in a manner approved by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region. 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. The documents may also be examined at FAA Northwest Region, 9010 East Marginal Way South, Seattle, Washington 98108.

Amendment 39-2812 supersedes AD 68-07-03 (Amendment 39-571), AD 68-16-03 (Amendment 39-629), and paragraph (a) of AD 64-11-01 (Amendment 39-763). Amendment 39-2812 became effective February 22, 1977. Amendment 39-3012 became effective August 15, 1977. This amendment 39-3067 becomes effective November 1, 1977.