# AD 88-24-12: Self-Locking Nut - Type: Airworthiness directive - Status: Current - Products: Boeing 727-100 Series, 727-100C Series, 727-200 Series, 727-200F Series, 727 Series and 727C Series - Effective: December 23, 1988 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Large airplane - Amendment: 39-6068 - Registered aircraft: 25 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/3616433E9ED973F98625695A0070F9A9.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/88-24-12 ## The airworthiness directive 88-24-12 BOEING: Amendment 39-6068. Applies to all Model 727 series airplanes, prior to line number 1620, not equipped with the safety bar modification described in Boeing Service Bulletin 727-32-275, Revision 2, dated March 30, 1984, certificated in any category. Compliance required within the next 3,500 flight cycles after the effective date of this AD, unless previously accomplished. To prevent failure of the main landing gear (MLG) to extend as a result of loosening of the self-locking nut at the attachment of the downlock forward pushrod assembly to the downlock torque shaft, accomplish the following: A. Modify airplanes listed in Boeing Service Bulletin 727-32-0237, Revision 5, dated July 7, 1988, by installing the bolt, washer, nut, and cotter pin called out in item 5 of Figure 5 of that service bulletin. B. Modify airplanes listed in Boeing Service Bulletin 727-32-0353, Revision 1, dated July 7, 1988, by installing the bolt, washer, nut, and cotter pin in accordance with that service bulletin. C. 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 may add any comments and then send it to the Manager, Seattle Aircraft Certification Office. D. 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 Airplanes, P.O. Box 3707, Seattle, Washington 98124. These documents may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle Washington, or Seattle Aircraft Certification Office, FAA, Northwest Mountain Region, 9010 East Marginal Way South, Seattle, Washington. This amendment, 39-6068, becomes effective December 23, 1988. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A3WE](https://openairdocs.org/tcds/A3WE): The Boeing Company; names 6 of 6 models: 727-100 Series, 727 Series, 727-200 Series, 727-100C Series, 727-200F Series, 727C Series ## 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: 25 (25 by airframe model, 0 by engine model) - Makers: Boeing 25 Models with the most aircraft: - [Boeing 727-223](https://openairdocs.org/model/boeing-727-223): 9 aircraft (airframe model) - [Boeing 727-227](https://openairdocs.org/model/boeing-727-227): 4 aircraft (airframe model) - [Boeing 727-225](https://openairdocs.org/model/boeing-727-225): 2 aircraft (airframe model) - [Boeing 727-200F](https://openairdocs.org/model/boeing-727-200f): 1 aircraft (airframe model) - [Boeing 727-200](https://openairdocs.org/model/boeing-727-200): 1 aircraft (airframe model) - [Boeing 727-212](https://openairdocs.org/model/boeing-727-212): 1 aircraft (airframe model) - [Boeing 727-230](https://openairdocs.org/model/boeing-727-230): 1 aircraft (airframe model) - [Boeing 727-232](https://openairdocs.org/model/boeing-727-232): 1 aircraft (airframe model) - [Boeing 727-243](https://openairdocs.org/model/boeing-727-243): 1 aircraft (airframe model) - [Boeing 727-247](https://openairdocs.org/model/boeing-727-247): 1 aircraft (airframe model) - [Boeing 727-264](https://openairdocs.org/model/boeing-727-264): 1 aircraft (airframe model) - [Boeing 727-281](https://openairdocs.org/model/boeing-727-281): 1 aircraft (airframe model) - [Boeing 727-277](https://openairdocs.org/model/boeing-727-277): 1 aircraft (airframe model) All 13 models: https://openairdocs.org/ad/88-24-12/models.md Every aircraft: https://openairdocs.org/ad/88-24-12/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.