AD 91-21-05

91-21-05 MCDONNELL DOUGLAS: Amendment 39-8052. Docket No. 91-NM-174-AD.

Applicability: Model DC-10-10, -10F, and -15 series airplanes, fuselage numbers through 379; and Model DC-10-30, -30F, and -40 series airplanes, fuselage numbers through 275; certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To ensure the structural integrity of these airplanes, accomplish the following:

(a) Except as provided in paragraphs (b) through (e) of this AD, prior to the accumulation of 7,000 landings or within 30 days after the effective date of this AD, conduct the initial inspections specified in paragraphs (a)(1), (a)(2), or (a)(3) of this AD.

(1) Conduct an eddy current inspection of the wing rear spar lower cap aft tang and a dye penetrant inspection of the wing trailing edge access door sill located between stations Xors= 417 and Xors= 424 in accordance with Option III of McDonnell Douglas Alert Service Bulletin A57-123, dated July 25, 1991. In addition, within 1,500 landings after performing these eddy current and dye penetrant inspections, conduct the inspections specified in paragraph (a)(2) or (a)(3) of this AD and repeat thereafter as indicated. Or

(2) Conduct an ultrasonic inspection of the area around the six wing rear spar lower cap aft tang fastener holes and a dye penetrant inspection of the wing trailing edge access door sill located between stations Xors= 417 and Xors= 424 in accordance with Option II of McDonnell Douglas Alert Service Bulletin A57-123, dated July 25, 1991. Repeat these inspections at intervals not to exceed 1,900 landings. Or

(3) Conduct an eddy current inspection of the six wing rear spar lower cap aft tang fastener holes and a dye penetrant inspection of the wing trailing edge access door sill located between stations Xors= 417 and Xors= 424 in accordance with Option I of McDonnell Douglas Alert Service Bulletin A57-123, dated July 25, 1991. Repeat these inspections at intervals not to exceed 3,300 landings.

(b) The requirements of paragraph (c) of this AD apply to airplanes on which the following actions have been accomplished:

(1) The dye penetrant inspection of the wing trailing edge access door sill located between stations Xors= 417 and Xors= 422 has been accomplished prior to the effective date of this AD, in accordance with McDonnell Douglas Service Bulletin 57-61, Revision 2, dated August 15, 1990; and

(2) The eddy current inspection of the wing rear spar lower cap aft tang has been accomplished prior to the effective date of this AD per DC-10 Supplemental Inspection Document, Principal Structural Element (PSE) 57.10.007 and 57.10.008, in accordance with McDonnell Douglas Service Bulletin 57-61, Revision 2, dated August 15, 1990.

(c) For airplanes specified in paragraph (b) of this AD, conduct the initial inspections specified in either paragraph (c)(1) or (c)(2) of this AD within 1,500 landings after the inspections (eddy current and dye penetrant) specified in paragraph (b)(1) of this AD, or within 30 days after the effective date of this AD, whichever occurs later.

(1) Conduct an ultrasonic inspection of the area around the six wing rear spar lower cap aft tang fastener holes and a dye penetrant inspection of the wing trailing edge access door sill located between stations Xors= 417 and Xors= 424, in accordance with Option II of McDonnell Douglas Alert Service Bulletin A57-123, dated July 25, 1991. Repeat these inspections at intervals not to exceed 1,900 landings. Or

(2) Conduct an eddy current inspection of the six wing rear spar lower cap aft tang fastener holes and a dye penetrant inspection of the wing trailing edge access door sill located between stations Xors= 417 and Xors= 424, in accordance with Option I of McDonnell Douglas Alert Service Bulletin A57-123, dated July 25, 1991. Repeat these inspections at intervals not to exceed 3,300 landings.

(d) The requirements of paragraph (e) of this AD apply to airplanes on which the following actions have been accomplished:

(1) The dye penetrant inspection of the wing trailing edge access door sill located between stations Xors= 417 and Xors= 422 has been accomplished prior to the effective date of this AD, in accordance with McDonnell Douglas Service Bulletin 57-61, Revision 2, dated August 15, 1990; and

(2) The eddy current inspection of the wing rear spar lower cap aft tang fastener holes located between stations Xors= 417 and Xors= 422 has been accomplished prior to the effective date of this AD per DPS 4.735-9 in accordance with McDonnell Douglas Service Bulletin 57-61, Revision 2, dated August 15, 1990.

(e) For airplanes specified in paragraph (d) of this AD, conduct the initial inspections specified in either paragraph (e)(1) or (e)(2) of this AD within 3,300 landings after the accomplishment of the inspection specified in paragraph (d)(1) of this AD, or within 30 days after the effective date of this AD, whichever occurs later.

(1) Conduct an ultrasonic inspection of the area around the six wing rear spar lower cap aft tang fastener holes and a dye penetrant inspection of the wing trailing edge access door sill located between stations Xors= 417 and Xors= 424 in accordance with Option II of McDonnell Douglas Alert Service Bulletin A57-123, dated July 25, 1991. Repeat these inspections at intervals not to exceed 1,900 landings. Or

(2) Conduct an eddy current inspection of the six wing rear spar lower cap aft tang fastener holes and a dye penetrant inspection of the wing trailing edge access door sill located between stations Xors= 417 and Xors= 424 in accordance with Option I of McDonnell Douglas Alert Service Bulletin A57-123, dated July 25, 1991. Repeat these inspections at intervals not to exceed 3,300 landings.

(f) If any cracks are found as a result of the inspections conducted in accordance with this AD, prior to further flight, repair ina manner approved by the Manager of the Los Angeles Aircraft Certification Office, FAA, Transport Airplane Directorate.

(g) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate to a base in order to comply with the requirements of this AD.

(h) An alternative method of compliance or adjustment time, which provides an acceptable level of safety, may be used when approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate.

NOTE: The request should be forwarded through the FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Los Angeles ACO.

(i) The inspection requirements shall be done in accordance with McDonnell Douglas Alert Service Bulletin A57-123, dated July 25, 1991. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from McDonnell Douglas Corporation, P.O. Box 1771, Long Beach California 90806-0001, Attention: Business Unit Manager of Technical Publications, Technical Administrative Support C1-L5B (54-60). Copies may be inspected at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington; or the Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California; or at the Office of the Federal Register, 1100 L Street N.W., Room 8401, Washington, D.C.

This amendment (39-8052, AD 91-21-05) becomes effective on October 23, 1991.