# AD 93-21-08: Front Spar Pylon Support Fittings - Type: Airworthiness directive - Status: Current - Products: Boeing DC-8-72, DC-8-72F, DC-8-73 and DC-8-73F - Effective: December 13, 1993 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Large airplane - Amendment: 39-8722 - Docket: 93-NM-66-AD - Registered aircraft: 5 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/8FCE6AE58DAD7CE786256A080065F104.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/93-21-08 ## The airworthiness directive 93-21-08 MCDONNELL DOUGLAS: Amendment 39-8722. Docket 93-NM-66-AD. Applicability: Model DC-8-72, -72F, -73, and -73F series airplanes, as listed in McDonnell Douglas DC-8-70 Alert Service Bulletin A57-99, dated December 10, 1992, certificated in any category. Compliance: Required as indicated, unless accomplished previously. To prevent reduced structural integrity of the pylon-to-wing main load path, accomplish the following: (a) Perform an eddy current inspection of the front spar pylon support fittings (part numbers 5753054-501 and -502) on the number 2 and number 3 engines, in accordance with McDonnell Douglas DC-8-70 Alert Service Bulletin A57-99, dated December 10, 1992, and at the time specified in paragraph (a)(1) or (a)(2) of this AD, as applicable. Thereafter, repeat this inspection at intervals not to exceed 720 landings. (1) For the number 2 engine: Prior to the accumulation of 4,000 landings since installation of that engine, or within 6 months after the effective date of this AD, whichever occurs later, unless accomplished previously within the last 720 landings prior to the effective date of this AD. (2) For the number 3 engine: Prior to the accumulation of 4,000 landings since installation of that engine, or within 6 months after the effective date of this AD, whichever occurs later, unless accomplished previously within the last 720 landings prior to the effective date of this AD. (b) If any crack is found, prior to further flight, repair it in accordance with a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. After repair, continue to repeat the inspection at intervals not to exceed 720 landings, in accordance with McDonnell Douglas DC-8-70 Alert Service Bulletin A57-99, dated December 10, 1992. (c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Los Angeles ACO, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Los Angeles ACO. NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO. (d) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished. (e) The inspections shall be done in accordance with McDonnell Douglas DC-8-70 Alert Service Bulletin A57-99, dated December 10, 1992. 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 90846-1771, Attention: Business Unit Manager, Technical Publications - Technical Administrative Support, C1-L5B. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California 90806-2425; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (f) This amendment becomes effective on December 13, 1993. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS 4A25](https://openairdocs.org/tcds/4A25): The Boeing Company; names 4 of 27 models: DC-8-72F, DC-8-73, DC-8-72, DC-8-73F ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 5 (5 by airframe model, 0 by engine model) - Makers: Douglas 5 Models with the most aircraft: - [Douglas DC-8-73](https://openairdocs.org/model/douglas-dc-8-73): 2 aircraft (airframe model) - [Douglas DC-8-73F](https://openairdocs.org/model/douglas-dc-8-73f): 2 aircraft (airframe model) - [Douglas DC-8-72](https://openairdocs.org/model/douglas-dc-8-72): 1 aircraft (airframe model) All 3 models: https://openairdocs.org/ad/93-21-08/models.md Every aircraft: https://openairdocs.org/ad/93-21-08/aircraft.md Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.