# AD 91-08-04: Pilot and Co-Pilot Seats - Type: Airworthiness directive - Status: Current - Products: Aviatech Pilot and Co-Pilot seats, DHC-8-101, DHC-8-102, DHC-8-103, DHC-8-106, DHC-8-201, DHC-8-202, DHC-8-301, DHC-8-311, DHC-8-315, DHC-8-400, DHC-8-401 and 1 more - Effective: May 6, 1991 - Superseded by: Nothing supersedes this AD - Product type: Appliance - Amendment: 39-6925 - Docket: 90-ANE-14 - Registered aircraft: 94 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/D40FDEE453E2300F86256A40005ADB99.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/91-08-04 ## The airworthiness directive 91-08-04 AVIATECH INC.: Amendment 39-6925. Docket No. 90-ANE-14. Applicability: Aviatech Inc., TSO-C39a Pilot and Co-Pilot seats Model 394 series as follows: Affected Pilot and Co-Pilot seats Part Numbers (P/N), 394 (000) 01,-02, -03, -04, -05, -06, and 394-(001) -01, -02, -03, -04,-05, -06, installed on, but not limited to, Boeing of Canada, Ltd., deHavilland Division, Model DHC-8. Compliance: Required within the next 90 days after the effective date of this AD, unless already accomplished. To prevent the pilot and co-pilot shoulder harness from becoming excessively worn and frayed, which could result in failure of the shoulder harness, accomplish the following: (a) Inspect the pilot and co-pilot seats to determine if any of the above P/Ns are inscribed on the FAA - TSO-C39a tag. (b) Modify all seats with any of the above P/Ns by incorporating the Aviatech Inc. Kit No. 394-25-002, which requires installing new backrest cushion-covers and a roller-guide for the shoulder harness, in accordance with Aviatech Service Bulletin No. 2, Model 394, Revision A, dated March 1, 1990 (Paragraph 2, Accomplishment Instructions). (c) Special flight permits may be issued in accordance with the provisions of FAR 21.197 and 21.199 to a base where the AD can be accomplished. (d) Upon submission of substantiating data by an owner or operator through an FAA Airworthiness Inspector, an alternate method of compliance with the requirements of this AD or adjustments to the compliance specified in this AD may be approved by the Manager, New York Aircraft Certification Office, Engine & Propeller Directorate, Aircraft Certification Service, FAA, 181 South Franklin Avenue, Room 202, Valley Stream, New York 11581. The modifications and installation procedures shall be done in accordance with the following Aviatech Service Bulletin (SB): DOCUMENT NO. PAGE NO. ISSUE/REVISION DATE Aviatech Inc. 1, 2, 4, 8, 10 Rev. A March 1, 1990 SB No. 2 3, 5, 6, 7, 9, 11 Original June 29, 1989 The incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Aviatech Inc., 2400 Guenette Street, St. Laurent, Quebec, Canada H4R 2H2. Copies may be inspected at the FAA, New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Room 311, Burlington, Massachusetts, or at the Office of the Federal Register, 1100 L Street, NW, Room 8401, Washington, DC. This amendment (39-6925, AD 91-08-04) becomes effective on May 6, 1991. AVIATECH 1 ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A13NM](https://openairdocs.org/tcds/A13NM): De Havilland Aircraft of Canada Limited; names 12 of 16 models: DHC-8-101, DHC-8-102, DHC-8-103, DHC-8-106, DHC-8-201, DHC-8-202, DHC-8-301, DHC-8-311… ## 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: 94 (94 by airframe model, 0 by engine model) - Makers: Bombardier 57, Dehavilland 28, Boeing Of Canada/Dehav Div 6, Boeing 3 Models with the most aircraft: - [Bombardier DHC-8-402](https://openairdocs.org/model/bombardier-dhc-8-402): 26 aircraft (airframe model) - [Dehavilland DHC-8-202](https://openairdocs.org/model/dehavilland-dhc-8-202): 17 aircraft (airframe model) - [Bombardier DHC-8-315](https://openairdocs.org/model/bombardier-dhc-8-315): 15 aircraft (airframe model) - [Bombardier DHC-8-202](https://openairdocs.org/model/bombardier-dhc-8-202): 14 aircraft (airframe model) - [Dehavilland DHC-8-106](https://openairdocs.org/model/dehavilland-dhc-8-106): 4 aircraft (airframe model) - [Boeing DHC-8-102](https://openairdocs.org/model/boeing-dhc-8-102): 3 aircraft (airframe model) - [Boeing Of Canada/Dehav Div DHC-8-311](https://openairdocs.org/model/boeing-of-canada-dehav-div-dhc-8-311): 3 aircraft (airframe model) - [Boeing Of Canada/Dehav Div DHC-8-106](https://openairdocs.org/model/boeing-of-canada-dehav-div-dhc-8-106): 2 aircraft (airframe model) - [Bombardier DHC-8-201](https://openairdocs.org/model/bombardier-dhc-8-201): 2 aircraft (airframe model) - [Dehavilland DHC-8-201](https://openairdocs.org/model/dehavilland-dhc-8-201): 2 aircraft (airframe model) - [Dehavilland DHC-8-103](https://openairdocs.org/model/dehavilland-dhc-8-103): 2 aircraft (airframe model) - [Dehavilland DHC-8-315](https://openairdocs.org/model/dehavilland-dhc-8-315): 2 aircraft (airframe model) - [Boeing Of Canada/Dehav Div DHC-8-102](https://openairdocs.org/model/boeing-of-canada-dehav-div-dhc-8-102): 1 aircraft (airframe model) - [Dehavilland DHC-8-102](https://openairdocs.org/model/dehavilland-dhc-8-102): 1 aircraft (airframe model) All 14 models: https://openairdocs.org/ad/91-08-04/models.md Every aircraft: https://openairdocs.org/ad/91-08-04/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.