# AD T91-17-51: Thrust Reversers - Type: Airworthiness directive - Status: Historical - Products: Boeing 767-200 Series, 767-300 Series and 767-300F Series - Effective: August 15, 1991 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Large airplane - Docket: 91-NM-178-AD - Registered aircraft: 402 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/0FFEA02B91A0EC89862569610072D7AB.0001 - DRS record last changed: August 7, 2025 - Page: https://openairdocs.org/ad/T91-17-51 ## The airworthiness directive T91-17-51 BOEING: Docket No. 91-NM-178-AD. Telegraphic AD issued on August 15, 1991. Applicability: Model 767 series airplanes equipped with Pratt and Whitney PW4000, General Electric CF6-80C2, or Rolls Royce RB211-524 series engines, certificated in any category. Compliance: Required as indicated, unless previously accomplished. To prevent potential in-flight thrust reverser deployments, within 7 days after receipt of this AD, accomplish the following: (a) Deactivate both left and right thrust reversers in accordance with Section 78-31-1 of Boeing Document D630T002, "Boeing 767 dispatch deviation guide," Revision 9, dated May 1, 1991. (b) Add the following to the limitations section of the FAA-approved Airplane Flight Manual (AFM): "REDUCE BY FIVE PERCENT THE AVAILABLE ACCELERATE-STOP DISTANCE RESULTING FROM THE AIRPLANE FLIGHT MANUAL TAKEOFF PERFORMANCE ANALYSIS WHEN THE RUNWAY IS WET OR CONTAMINATED." This may be accomplished by placing a copyof this AD in the AFM. (c) An alternative method 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 (ACO), FAA, Transport Airplane Directorate. NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Seattle ACO. (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. Telegraphic AD T91-17-51, issued on August 15, 1991, supersedes Amendment 39- 7073, AD 91-15-09, and is effective immediately upon receipt. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [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: 402 (402 by airframe model, 0 by engine model) - Makers: Boeing 402 Models with the most aircraft: - [Boeing 767-300F](https://openairdocs.org/model/boeing-767-300f): 169 aircraft (airframe model) - [Boeing 767-332](https://openairdocs.org/model/boeing-767-332): 46 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 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 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 767-232](https://openairdocs.org/model/boeing-767-232): 6 aircraft (airframe model) - [Boeing 767-319](https://openairdocs.org/model/boeing-767-319): 6 aircraft (airframe model) - [Boeing 767-306](https://openairdocs.org/model/boeing-767-306): 5 aircraft (airframe model) - [Boeing 767-224](https://openairdocs.org/model/boeing-767-224): 5 aircraft (airframe model) - [Boeing 767-300](https://openairdocs.org/model/boeing-767-300): 5 aircraft (airframe model) - [Boeing 767-316F](https://openairdocs.org/model/boeing-767-316f): 5 aircraft (airframe model) - [Boeing 767-336](https://openairdocs.org/model/boeing-767-336): 4 aircraft (airframe model) - [Boeing 767-223](https://openairdocs.org/model/boeing-767-223): 3 aircraft (airframe model) - [Boeing 767-231](https://openairdocs.org/model/boeing-767-231): 3 aircraft (airframe model) - [Boeing 767-304](https://openairdocs.org/model/boeing-767-304): 3 aircraft (airframe model) - [Boeing 767-324](https://openairdocs.org/model/boeing-767-324): 3 aircraft (airframe model) All 36 models: https://openairdocs.org/ad/T91-17-51/models.md Every aircraft: https://openairdocs.org/ad/T91-17-51/aircraft.md It also names AD T91-18-51, which this release has no record of. 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.