# AD 83-21-04: Outflow Valve Assemblies - 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757-200PF Series, 757-300 Series, 767-200 Series, 767-300 Series and 767-300F Series - Effective: November 28, 1983 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Large airplane - Amendment: 39-4750 - Registered aircraft: 672 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/7D0E40491D8A029F862568A80074CE93.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/83-21-04 ## The airworthiness directive 83-21-04 BOEING: Amendment 39-4750. Applies to Boeing Model 767 and 757 series airplanes identified in the Boeing Service Bulletins listed in paragraph A., below. To prevent the loss of pressurization control due to failure of the cabin pressure control, accomplish the following within 750 hours time in service after the effective date of this AD, unless already accomplished: A. Inspect and rework outflow valve actuators per Boeing Service Bulletins 757-21-9 or 767-21-13 dated May 23, 1983, and March 31, 1983, respectively as applicable, or later FAA approved revisions. B. Rework the outflow valve assemblies per Boeing Service Bulletins 757-21-9 or 767- 21-15, Rev. 1, dated May 23, 1983, and March 31, 1983, respectively, as applicable, or later FAA approved revisions. C. Alternate means of compliance which provide an equivalent level of safety may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. D. 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 directive who have not already received the service bulletin(s) may obtain copies upon request from the Boeing Commercial Airplane Company, P.O. Box 3707, Seattle, Washington 98124. These documents may also be examined at the FAA, Northwest Mountain Region, 9010 East Marginal Way South, Seattle, Washington. This amendment becomes effective November 28, 1983. ## 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/83-21-04/models.md Every aircraft: https://openairdocs.org/ad/83-21-04/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.