AD 64-11-01 R7

64-11-01 BOEING: Amendment 39-763. Applies to models 707 and 720 Series Aircraft. Compliance required as indicated.

Cracks have been discovered in the front and rear upper and lower wing spar chords on the 707/720 Series aircraft. Accordingly, in the interest of safety accomplish the following or an equivalent approved by Aircraft Engineering Division, FAA Western Region:

(a) Paragraph (a) Superseded by AD 77-02-01.

(b) On all 707 and 720 Series aircraft delivered prior to October 1962, accomplish the following:

(1) On 707 and 720 Series aircraft which have been inspected in accordance with AD 64-03-02, paragraph (b), visually reinspect thereafter at intervals not to exceed 6,000 hours' time in service for spanwise cracks in the wing upper and lower front spar chords between front spar Station 727 and the production break fittings.

(2) If a crack is detected, repair the cracked spar chord in accordance with Boeing front spar repair drawing 65-40144 oran Aircraft Engineering Division, FAA Western Region, approved equivalent before further flight. The repetitive inspections required by subparagraph (1) may be discontinued on any chord repaired in accordance with this subparagraph.

(c) 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.

NOTE. - This AD supplements but does not cancel AD 64-03-02.

(Boeing Service Bulletins No. 1964 (R-3) and No. 1964(R-3)A cover this same subject.)

This directive effective May 21, 1964.

Revised August 22, 1964.

Revised March 5, 1965.

Revised May 1, 1965.

Revised August 20, 1968.

Revised October 29, 1968.

Revised March 22, 1969.Revised May 9, 1969.