AD 74-08-10

74-08-10 BOEING: Amendment 39-1817. Applies to forward electronic hatches on all model 747 series airplanes certificated in all categories. Compliance required as indicated. To detect cracks in the hatch, accomplish the following: (a) Within the next 100 hours time in service from the effective date of this AD, visually inspect the forward electronic hatch on airplanes having 5,000 or more hours time in service, unless inspected within the last 100 hours. If no cracks are found, or if repaired in accordance with paragraph (e), or if the hatch is replaced with a hatch which has not been modified in accordance with Boeing Service Bulletin 747-52-2088, repeat the inspection every 500 hours time in service until modified in accordance with the termination action specified in Boeing Service Bulletin 747-52-2088, or in a manner approved by the Chief, Engineering and Manufacturing Branch, FAA, Northwest Region. (b) If cracks are found in the frame or outer skin, repair the cracks in accordance with paragraph (e), or replace the hatch before further flight. (c) If cracks are found in the channel stiffeners or in the horizontal angles on the lower side of the hatch, replace or repair in accordance with paragraph (e), or reinspect every 100 hours and repair within 1,000 hours time in service from effective date of this AD or from discovery of the cracks, whichever is later. The hatch must be replaced or repaired prior to further flight, if cracks in any one horizontal angle P/N 65B11898-2 or -4 exceed 5 inches in length or a combined crack length of 8 inches in both angles. (d) Any broken latch pin must be replaced prior to further flight. (e) Hatch repairs shall be accomplished in accordance with the FAA approved Boeing 747 Structural Repair Manual, or Boeing Service Bulletin 747-52-2088 or later FAA approved revisions, or in a manner approved by the Chief, Engineering and Manufacturing Branch, FAA, Northwest Region. (f) Modification of the forwardelectronic hatch in accordance with Boeing Service Bulletin 747-52-2088 or in a manner approved by the Chief, Engineering and Manufacturing Branch, FAA, Northwest Region, constitutes terminating action under the provisions of this AD. (g) Upon request of the operator, an FAA Maintenance Inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA, Northwest 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 adjustment. Aircraft may be ferried to a base for maintenance in accordance with Sections 21.197 and 21.199 of the Federal Aviation Regulations. The manufacturer's specifications and procedures identified and described in this directive are incorporated herewith and made a part hereof, pursuant to 5 U.S.C. 552(a)(i). All persons affected by this directive who have not already received these documents may obtain copies upon request to The Boeing Company, P.O. Box 3707, Seattle, Washington 98124. These documents may also be examined at FAA Northwest Region, Boeing Field, Seattle, Washington.

This amendment becomes effective upon publication in the Federal Register.