# AD 85-24-02: Air Conditioning Ram Air Plenum Chamber - Type: Airworthiness directive - Status: Current - Products: Boeing 727-200 Series - Effective: December 23, 1985 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Large airplane - Amendment: 39-5170 - Registered aircraft: 24 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/00477C4384BB64AB862568AA0065655E.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/85-24-02 ## The airworthiness directive 85-24-02 BOEING: Amendment 39-5170. Applies to all Model 727-200 series airplanes, certificated in any category. Compliance is required as indicated, unless previously accomplished. To detect corrosion of the wing lower skin that could result in fuel entering the ram air plenum chamber accomplish the following: A. On airplanes with more than 10,000 hours time-in-service or 4 years since date of manufacture, accomplish the following within the next 3,000 hours time-in-service or 1 year, whichever occurs first after the effective date of this AD: 1. Visually inspect the upper wall of the air conditioning ram air plenum chamber for corrosion in accordance with Part II of Boeing Service Bulletin 727-51-17, dated April 26, 1974, or later FAA approved revision. 2. If corrosion is detected, repair and refinish in accordance with Figure 3 of the Boeing Service Bulletin 727-51-17 dated April 26, 1974, or later FAA-approved revision, or in a manner approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. B. Repeat the procedures required in paragraph A., above, at intervals not to exceed either 8,000 hours time-in-service or 4 years, whichever occurs first. C. Inspections accomplished in accordance with Part II of Boeing Service Bulletin 727-51-17 prior to the effective date of this AD satisfy the initial inspection requirements of this AD. D. Alternate means of compliance which provide an acceptable level of safety may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. E. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of inspections and/or modifications required by this AD. All persons affected by this proposal who have not already received these documents from the manufacturer may obtain copies upon request to the Boeing Commercial Airplane Company, P.O. Box 3707, Seattle, Washington 98124-2207. These documents may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or the Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington. This amendment becomes effective December 23, 1985. ## 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 1 of 6 models: 727-200 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: 24 (24 by airframe model, 0 by engine model) - Makers: Boeing 24 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 727-200](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 12 models: https://openairdocs.org/ad/85-24-02/models.md Every aircraft: https://openairdocs.org/ad/85-24-02/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.