# AD 75-26-05: Main Rotor Blades - Type: Airworthiness directive - Status: Historical - Products: Bell Helicopter Textron 204B, 205A-1 and 212 - Effective: January 19, 1976 - Superseded by: [AD 2016-22-07](https://openairdocs.org/ad/2016-22-07) - Product type: Aircraft, Rotorcraft - Amendment: 39-2457 - Registered aircraft: 125 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/11FEF05FE5514AA186256A340054328D.0001 - DRS record last changed: August 7, 2025 - Page: https://openairdocs.org/ad/75-26-05 ## The airworthiness directive 75-26-05 BELL: Amendment 39-2457. Applies to Bell Models 204B, 205A-1, and 212 helicopters certificated in all categories. (a) Compliance required as follows: (1) For main rotor blades having 12 or more months' installed time on a helicopter, on the effective date of this AD, conduct inspections within 90 days' time unless already accomplished. (2) For main rotor blades having less than 12 months' installed time on a helicopter on the effective date of this AD, conduct inspections prior to attaining 15 months' installed time on a helicopter. (3) Conduct repetitive inspections at intervals not to exceed 12 months' installed time from the last inspection. (b) To detect possible cracks and corrosion and to prevent further corrosion in the main rotor blade inboard portion, accomplish the following: (1) Remove the main rotor blades from the helicopter and prepare the blades for inspection as noted in Bell Helicopter Company Service Bulletin No. 205-75-5, revision A, dated October 22, 1975, or later approved revisions, Part III, paragraph A. (2) Inspect the blades as noted in Service Bulletin No. 205-75-5, revision A, or later approved revisions, Part III, paragraph A. Blades with cracks or adhesive voids exceeding the limits specified in Service Bulletin No. 205-75-5, revision A, Part III, paragraph A, may not be returned to service. (3) Repair discrepant blades as specified in Service Bulletin No. 205-75-5, revision A, or later approved revisions, Part III, paragraph A. Refinish discrepant blades as specified in Part III, paragraph B. (4) Install blades on the helicopter in accordance with the applicable model maintenance and overhaul information manual and balance and track the blades. (c) Equivalent means of compliance with paragraph (b) of this AD may be approved by the Chief, Engineering and Manufacturing Branch, Flight Standards Division, Southwest Region, Federal Aviation Administration, Fort Worth, Texas. Bell Service Bulletins No. 204-75- 1, revision A, dated October 22, 1975, No. 212-75-6, revision A, dated October 22, 1975, or later FAA-DER approved revisions to these bulletins are approved as equivalent means of compliance with paragraph (b). (d) Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, Flight Standards Division, FAA, Southwest Region, may adjust the repetitive inspection intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for that operator. (e) The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Service Manager, Bell Helicopter Company, P.O. Box 482, Fort Worth, Texas 76101. These documents may also be examined at the Office of the Regional Counsel, Southwest Region, FAA, 4400 Blue Mound Road, Fort Worth, Texas, and at FAA headquarters, 800 Independence Avenue, S.W., Washington, D.C. A historical file on this AD which includes the incorporated material in full is maintained by the FAA at its headquarters in Washington, D.C., and at the Office of the Regional Counsel, Southwest Region, FAA, 4400 Blue Mound Road, Fort Worth, Texas. This amendment becomes effective January 19, 1976. ## Affected data sheets (2) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS H1SW](https://openairdocs.org/tcds/H1SW): Bell Textron Inc.; names 2 of 5 models: 204B, 205A-1 - [TCDS H4SW](https://openairdocs.org/tcds/H4SW): Bell Textron Inc.; names 1 of 4 models: 212 ## 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: 125 (125 by airframe model, 0 by engine model) - Makers: Bell 117, Bell Helicopter Textron 6, Bell/Southwest Florida Aviatio 2 Models with the most aircraft: - [Bell 205A-1](https://openairdocs.org/model/bell-205a-1): 56 aircraft (airframe model) - [Bell 212](https://openairdocs.org/model/bell-212): 54 aircraft (airframe model) - [Bell 204-B](https://openairdocs.org/model/bell-204-b): 7 aircraft (airframe model) - [Bell Helicopter Textron 212](https://openairdocs.org/model/bell-helicopter-textron-212): 5 aircraft (airframe model) - [Bell/Southwest Florida Aviatio 205 A1](https://openairdocs.org/model/bell-southwest-florida-aviatio-205-a1): 2 aircraft (airframe model) - [Bell Helicopter Textron 205A-1](https://openairdocs.org/model/bell-helicopter-textron-205a-1): 1 aircraft (airframe model) All 6 models: https://openairdocs.org/ad/75-26-05/models.md Every aircraft: https://openairdocs.org/ad/75-26-05/aircraft.md ## Related documents - [AD 2016-22-07](https://openairdocs.org/ad/2016-22-07): Main Rotor Blades · Bell Helicopter Textron 204B, 205A and 205A-1. Effective Nov 30, 2016. Supersedes this AD Its text cites no advisory circulars or STCs. ## NTSB investigations that cite this AD (1) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB FTW97FA330](https://openairdocs.org/ntsb/FTW97FA330), Aug 27, 1997: Southwest Florida SW204 (N482SA), Manila, AR, destroyed, 1 fatal. Probable cause: Fatigue failure of the main rotor blade resulting in the in-flight separation of the main rotor system due to the use of an unairworthy blade, and failure of the maintenance personnel who modified… --- 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.