AD 82-24-03

82-24-03 BOEING: Amendment 39-4496. Applies to all Model 707/720 series airplanes listed in Boeing Service Bulletin A3364, Revision 3, NSC-2 and later FAA approved revisions with nacelle strut diagonal braces and associated fittings which have accumulated 7500 or more landings.

To detect cracks in the nacelle strut diagonal brace and associated fittings accomplish the following:

A. Within 500 landings after the effective date of this AD unless already accomplished, inspect the nacelle strut diagonal braces and associated fittings in accordance with Boeing Service Bulletin A3364, Rev. 3, NSC2 or later FAA-approved revisions, and repeat thereafter at the intervals specified in Tables 1, 2, and 3 below.

B. If cracks are found, replace the cracked part prior to further flight or repair in a manner approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. Parts oversized beyond the limits specified in Boeing Service Bulletin A3364 must be replaced prior to further flight.

C. For Group III, IV, and VI airplanes, as specified in the service bulletin, replace the diagonal brace assembly if the outboard diagonal brace end fitting (forward or aft) attach holes have been oversized beyond the limits specified in Boeing Service Bulletin A3364, Rev. 3 or later FAA-approved revisions within 1000 landings since oversizing.

D. Alternate means of compliance which provide an equivalent level of safety may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region.

TABLE I

Forward Mating Fitting

Type Inspection Repeat Intervals Not To Exceed Landings Visual 250 Hi frequency 7500 Hi frequency followed by shot peening 12000

TABLE II

Aft Mating Fitting

Type Inspection Repeat Intervals Not To Exceed Landings Visual 250 1. Hi frequency or dye penetrant of web. 7500 2. Hi frequency of lug hole with bushing removed and hole oversized.

1. Hi frequency of lug hole with bushing removed, oversizing and peening of lug hole surface. 12000 2. Hi frequency or dye penetrant of web and preening of web.

TABLE III

Diagonal Brace Assembly

Type Inspection Repeat Intervals Not To Exceed Landings Hi frequency Interior only 2500 Hi frequency Exterior (fitting removal) with hole oversizing. 7500 Hi frequency Exterior with hole oversizing and peening 12000 Hi frequency Exterior with holes previously oversized to limit and peening. 7500

NOTE: Hole oversizing cannot exceed limits specified in Service Bulletin.

The manufacturer's specification 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). All persons affected by this directive who have not already received these documents may obtain copies upon request to Boeing Commercial Airplane Company, P.O. Box 3707, Seattle, Washington 98124. These documents may also be examined at the FAA, Northwest Mountain Region, 9010 East Marginal Way South, Seattle, Washington.

This AD supersedes AD 80-14-14.

This amendment becomes effective November 23, 1982.