90-02-16 BOEING: Amendment 39-6452. Docket No. 89-NM-116-AD. \n\n\tApplicability: Model 727 series airplanes, listed in Boeing Service Bulletin 727-57-0177, dated December 22, 1988, certificated in any category. \n\n\tCompliance: Required as indicated, unless previously accomplished. \n\n\tTo detect cracks in the wing center section front spar, accomplish the following: \n\n\tA. Prior to the accumulation of 40,000 flight cycles or within the next 2,300 flight cycles after the effective date of this AD, whichever occurs later, unless accomplished within the last 700 flight cycles, conduct either a close visual or a high frequency eddy current inspection of the wing center section front spar web, between the upper and lower seals, for cracks, in accordance with Figure 1 of Boeing Service Bulletin 727-57-0177, dated December 22, 1988. Repeat the inspection as follows: \n\n\t1. If the immediately preceding inspection was conducted visually, conduct the next inspection within 3,000 flight cycles. \n\n\t2. If the immediately preceding inspection was conducted using high frequency eddy current techniques, conduct the next inspection within 4,500 flight cycles. \n\n\tB. Repair cracks prior to further flight, in accordance with Figure 2 of Boeing Service Bulletin 727-57- 0177, dated December 22, 1988. \n\n\tC. Modification in accordance with Figure 3 of Boeing Service Bulletin 727-57-0177, dated December 22, 1988, or repair in accordance with paragraph B., above, constitutes terminating action for the repetitive inspections required by paragraph A., above. \n\n\tD. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment, and then send it to the Manager, Seattle Aircraft Certification Office.\n\n\tE. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD. All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Boeing Commercial Airplane, P.O. Box 3707, Seattle, Washington 98124. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington. \n\n\tThis amendment (39-6452, AD 90-02-16) becomes effective on February 12, 1990.