62-21-04 LOCKHEED: Amdt. 489 Part 507 Federal Register October 3, 1962. Applies to All Model 1649A Aircraft.
Compliance required as indicated.
As a result of chordwise cracks on the wing lower milled skin at wing Station 590, the following shall be accomplished:
(a) Within the next 400 hours' time in service after the effective date of this AD, unless already accomplished within the past 600 hours' time in service, and at periods thereafter not exceeding 1,000 hours' time in service following that initial inspection, inspect from wing Station 580 through wing Station 600, the external lower surface of the aft skin panels, P/N 472066, for any evidence of cracks emanating from the aft edge of the panel through the rear beam attachment holes. Inspection shall be by close visual or dye penetrant means.
(b) Any cracks shall be repaired prior to further flight in accordance with Lockheed 1649 Service Bulletin No. 73, Section 1, "Modification Data," and Lockheed Drawing SED61- 9004, or an equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA Western Region.
(c) The periodic inspections may be discontinued following repair per (b) or when an uncracked skin panel has been reinforced in accordance with Lockheed 1649 Service Bulletin No. 73.
(d) Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, 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.
(Lockheed Field Service Letter FS/240893L, dated April 14, 1960, and Lockheed 1649 Service Bulletin No. 73 cover this same subject.)
This directive effective November 2, 1962.