# AD 89-23-02: Ram Air Turbine - Type: Airworthiness directive - Status: Current - Products: Boeing 757-200 Series, 757-200CB Series, 757-200PF Series, 757-300 Series, 767-200 Series, 767-300 Series and 767-300F Series - Effective: December 1, 1989 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Large airplane - Amendment: 39-6373 - Docket: 89-NM-100-AD - Registered aircraft: 672 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/7FA4C7F8D4816EB48625695E00603D84.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/89-23-02 ## The airworthiness directive 89-23-02 BOEING: Amendment 39-6373. Docket No. 89-NM-100-AD. Applicability: Model 757 and 767 series airplanes, as listed in Boeing Alert Service Bulletins 757-29A0037, Revision 1, and 767-29A0035, Revision 1, both dated November 23, 1988, certificated in any category. Compliance: Required within the next 6,000 hours time-in-service after the effective date of this AD, unless previously accomplished. To prevent the possible complete loss of hydraulic power, accomplish the following: A. Remove and rework or replace the Ram Air Turbine (RAT) Ground Checkout Module (GCM) in accordance with Boeing Service Bulletin 757-29A0037, Revision 1, dated November 23, 1988, or Revision 2, dated August 3, 1989 (for Model 757 airplanes); or Boeing Service Bulletin 767-29A0035, Revision 1, dated November 23, 1989, or Revision 2, dated August 3, 1989 (for Model 767 airplanes); as appropriate. Prior to returning the airplane to service: 1. If the RAT has been operated ortested since the airplane delivery, prior to returning the airplane to service, inspect the downstream filter screen of the removed GCM. 2. If the screen is damaged or missing, or if GCM has been removed previously without inspecting the screen, prior to further flight, either test the RAT hydraulic pump or replace it in accordance with the applicable service bulletins. 3. If the RAT hydraulic pump is tested and found to be damaged, prior to further flight, replace it with a serviceable pump in accordance with the applicable service bulletin. B. 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. C. 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, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington. This amendment (39-6373, AD 89-23-02) becomes effective on December 1, 1989. ## Affected data sheets (2) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A2NM](https://openairdocs.org/tcds/A2NM): The Boeing Company; names 4 of 4 models: 757-200CB Series, 757-200PF Series, 757-300 Series, 757-200 Series - [TCDS A1NM](https://openairdocs.org/tcds/A1NM): The Boeing Company; names 3 of 5 models: 767-300 Series, 767-200 Series, 767-300F 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: 672 (672 by airframe model, 0 by engine model) - Makers: Boeing 672 Models with the most aircraft: - [Boeing 767-300F](https://openairdocs.org/model/boeing-767-300f): 169 aircraft (airframe model) - [Boeing 757-232](https://openairdocs.org/model/boeing-757-232): 63 aircraft (airframe model) - [Boeing 767-332](https://openairdocs.org/model/boeing-767-332): 46 aircraft (airframe model) - [Boeing 757-224](https://openairdocs.org/model/boeing-757-224): 40 aircraft (airframe model) - [Boeing 757-222](https://openairdocs.org/model/boeing-757-222): 38 aircraft (airframe model) - [Boeing 767-322](https://openairdocs.org/model/boeing-767-322): 36 aircraft (airframe model) - [Boeing 767-323](https://openairdocs.org/model/boeing-767-323): 27 aircraft (airframe model) - [Boeing 757-223](https://openairdocs.org/model/boeing-757-223): 23 aircraft (airframe model) - [Boeing 757-236](https://openairdocs.org/model/boeing-757-236): 20 aircraft (airframe model) - [Boeing 757-251](https://openairdocs.org/model/boeing-757-251): 18 aircraft (airframe model) - [Boeing 757-351](https://openairdocs.org/model/boeing-757-351): 16 aircraft (airframe model) - [Boeing 757-231](https://openairdocs.org/model/boeing-757-231): 13 aircraft (airframe model) - [Boeing 767-338](https://openairdocs.org/model/boeing-767-338): 13 aircraft (airframe model) - [Boeing 767-316](https://openairdocs.org/model/boeing-767-316): 12 aircraft (airframe model) - [Boeing 767-346](https://openairdocs.org/model/boeing-767-346): 11 aircraft (airframe model) - [Boeing 757-324](https://openairdocs.org/model/boeing-757-324): 9 aircraft (airframe model) - [Boeing 767-281](https://openairdocs.org/model/boeing-767-281): 9 aircraft (airframe model) - [Boeing 767-381](https://openairdocs.org/model/boeing-767-381): 8 aircraft (airframe model) - [Boeing 757-200 SERIES](https://openairdocs.org/model/boeing-757-200-series): 7 aircraft (airframe model) - [Boeing 757-204](https://openairdocs.org/model/boeing-757-204): 6 aircraft (airframe model) All 52 models: https://openairdocs.org/ad/89-23-02/models.md Every aircraft: https://openairdocs.org/ad/89-23-02/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.