AD 64-15-02

64-15-02 BOEING: Amdt. 758 Part 507 Federal Register July 7, 1964. Applies to All Models 720 and 720B Series Aircraft.

Compliance required within 250 hours' time in service after the effective date of this AD for aircraft with 5,000 or more hours' time in service, and prior to the accumulation of 5,250 hours' time in service for aircraft with less than 5,000 hours' time in service, unless already accomplished, and thereafter at periods not to exceed 600 hours' time in service from the last inspection.

Cracks have occurred in the inboard wing upper skin just aft of the front spar and inboard of the inboard nacelle overwing support fitting at approximately front spar Station 405. The cracks found were generally in a chord-wise direction. To correct this condition, accomplish the following or an equivalent approved by Aircraft Engineering Division, FAA Western Region.

(a) Inspect visually or by a dye penetrant method for cracks in the upper wing skin in accordance with paragraph 3, Part I, "Inspection and Repair Data" of Boeing Service Bulletin No. 1983(R-1) dated May 5, 1964.

(b) Repair cracks detected in the affected skin area in accordance with Boeing Drawing 65-40293, Sheets 1 and 2 or the Boeing Structural Repair Manual, before further flight. Repair any other crack(s) found during the inspection of paragraph (a) in accordance with an Aircraft Engineering Division, FAA Western Region, approved repair.

(c) The repetitive inspections specified herein may be discontinued when the rework specified in Part II of Boeing Service Bulletin No. 1983 (R-1) is accomplished or repairs are made in accordance with (b).

(d) Upon request of an operator, an FAA maintenance inspector, subject to prior approval of the Chief, Aircraft Engineering Division, FAA Western Region, may adjust the repetitive inspection intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for such operator.

(Boeing Service Bulletin No. 1983(R-1) covers this same subject.)

This directive effective July 7, 1964.

Revised August 21, 1964.

Revised June 17, 1965.