# AD 2002-20-01: TT strap - Type: Airworthiness directive - Status: Current - Products: Overseas Aircraft Support UH-1H, UH-1F, TH-1L, UH-1E, UH-1L, UH-1H, UH-1H, UH-1B, TH-1L, UH-1B, UH-1E, UH-1H and 25 more - Effective: November 6, 2002 - Published: October 2, 2002, 67 FR 61771–61773 - Issued: September 18, 2002 - Issued as: Final rule - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Rotorcraft - Amendment: 39-12895 - Docket: 2001-SW-41-AD - Registered aircraft: 380 may be affected, by airframe or engine model (OpenAirDocs) - Official PDF: https://openairdocs.org/files/sha256/31/0c/310c887ca9222c6ddd98b5dbcfe579b38e75dfe78d8742049d5571509eb7974a (from https://www.govinfo.gov/content/pkg/FR-2002-10-02/pdf/02-24993.pdf) - Federal Register: https://www.federalregister.gov/documents/2002/10/02/02-24993/airworthiness-directives-model-hh-1k-th-1f-th-1l-uh-1a-uh-1b-uh-1e-uh-1f-uh-1h-uh-1l-and-uh-1p-and - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/202C1470C7EFD3EB86256C4600575AA1.0001 - DRS record last changed: November 21, 2025 - Page: https://openairdocs.org/ad/2002-20-01 ## Summary This amendment adopts a new airworthiness directive (AD) for the specified military surplus helicopters that requires updating the product identification, extending the application of the AD to other models, continuing the existing retirement time for certain main rotor tension-torsion (TT) straps, and adding the TT strap part numbers to the applicability. This amendment is prompted by the need to expand the applicability to additional military surplus helicopters and to add two part numbers to the applicability. The actions specified by this AD are intended to prevent failure of a TT strap, loss of a main rotor blade, and subsequent loss of control of the helicopter. ## The airworthiness directive ### Adoption of the Amendment Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: 1. The authority citation for part 39 continues to read as follows: 2. Section 39.13 is amended by adding a new airworthiness directive to read as follows: 2002-20-01 Arrow Falcon Exporters, Inc. (previously Utah State University); Firefly Aviation Helicopter Services (previously Erickson Air-Crane Co.); Garlick Helicopters, Inc.; Global Helicopter Technology, Inc.; Hagglund Helicopters, LLC (previously Western International Aviation, Inc.); Hawkins and Powers Aviation, Inc.; International Helicopters, Inc.; Robinson Air Crane, Inc.; Smith Helicopters; Southern Helicopter, Inc.; Southwest Florida Aviation; Tamarack Helicopters, Inc. (previously Ranger Helicopter Services, Inc.); U.S. Helicopter, Inc.; and Williams Helicopter Corporation (previously Scott Paper Co.): Amendment 39-12895. Docket No. 2001-SW-41-AD. Applicability: Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P; and Southwest Florida Aviation Model SW204, SW204HP, SW205, and SW205A-1 helicopters, manufactured by Bell Helicopter Textron, Inc. (BHTI) for the Armed Forces of the United States, with main rotor tension-torsion (TT) strap, part number (P/N) 204-012-122-1, 204-012-122-5, 2601399, or 2606650, installed, certificated in any category. Note 1: This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it. Compliance: Required before further flight, unless accomplished previously. To prevent failure of a TT strap, loss of a main rotor blade, and subsequent loss of control of the helicopter, accomplish the following: (a) Remove and replace any TT strap with 1,200 hours time-in-service (TIS) or 24 months since the initial installation, whichever occurs first. (b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Rotorcraft Certification Office, Rotorcraft Directorate, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Rotorcraft Certification Office. Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Rotorcraft Certification Office. (c) Special flight permits will not be issued. (d) This amendment becomes effective on November 6, 2002. ## Rule preamble ### Dates Effective November 6, 2002. ### For further information contact Michael Kohner, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Rotorcraft Certification Office, Fort Worth, Texas 76193-0170, telephone (817) 222-5447, fax (817) 222-5783. ### SUPPLEMENTARY INFORMATION A proposal to amend 14 CFR part 39 to include an AD for Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P; and Southwest Florida Aviation Model SW204, SW204HP, SW205, and SW205A-1 helicopters was published in the Federal Register on April 10, 2002 (67 FR 17305). That action proposed updating the product identification, extending the application of the AD to other models, continuing the existing retirement time for certain TT straps, and adding the TT strap part numbers to the applicability for the specified military surplus helicopters. Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received. One commenter states that Model AH-1 series helicopter should be added to the applicability section of the AD, because Model AH-1 series helicopters are currently being operated in experimental and restricted categories, and have identical TT straps as the HH-1K and UH-1L helicopter that are included in the applicability of the AD. The commenter also states that the FAA should evaluate TT strap, part number 204-310-101-101, because “this current production TT strap is life-limited * * * to 1,200 hours of operation or a calendar time of two years” when installed on standard category type certificated Bell products. The FAA concurs, however the intent of AD's, Docket Numbers 2001-SW-41-AD and 2001-SW-42-AD, was to update the model applicability and type certificate holders of AD 80-17-09 for the Model UH-1 military surplus helicopters. If we were to add the additional helicopter models or part numbers as proposed by the commenter, we would need to issue a Supplemental Notice of Proposed Rulemaking. To avoid further delay in the effectivity of the published proposals, we are issuing this final rule as proposed. The comments suggesting an expansion of these AD provisions to additional model helicopters and TT strap part numbers will be further evaluated and may be incorporated into a subsequent AD. After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed. The FAA estimates that 75 helicopters of U.S. registry will be affected by this AD, that it will take approximately 8 work hours per helicopter to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $10,484 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $822,300. The regulations adopted herein will not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132. For the reasons discussed above, I certify that this action (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption ADDRESSES. ## Affected data sheets (4) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS H6SO](https://openairdocs.org/tcds/H6SO): Southwest Florida Aviation International; names 2 of 4 models: SW204HP (UH-1B), SW205A-1 - [TCDS R00008AT](https://openairdocs.org/tcds/R00008AT): Robinson Air Crane Inc.; names 2 of 3 models: TH-1F, UH-1P - [TCDS H3SO](https://openairdocs.org/tcds/H3SO): Richards Heavylift Helo Inc.; names 1 of 4 models: UH-1A - [TCDS H5NM](https://openairdocs.org/tcds/H5NM): Midwest Aerospace TC LLC; names 1 of 4 models: HH-1K ## 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: 380 (380 by airframe model, 0 by engine model) - Makers: Bell 344, Williams Helicopter 7, Northwest Rotorcraft 6, Southwest Florida 4, Bell Helicopter 3, Arrow Falcon Exporters 2, Garlick Helicopters 2, Hawkins & Powers 2, Richards Heavylift Helo 2, Rotorcraft Development 2 Models with the most aircraft: - [Bell UH-1H](https://openairdocs.org/model/bell-uh-1h): 291 aircraft (airframe model) - [Bell UH-1B](https://openairdocs.org/model/bell-uh-1b): 42 aircraft (airframe model) - [Bell UH-1E](https://openairdocs.org/model/bell-uh-1e): 6 aircraft (airframe model) - [Northwest Rotorcraft UH-1H](https://openairdocs.org/model/northwest-rotorcraft-uh-1h): 6 aircraft (airframe model) - [Williams Helicopter UH-1H](https://openairdocs.org/model/williams-helicopter-uh-1h): 6 aircraft (airframe model) - [Bell UH-1F](https://openairdocs.org/model/bell-uh-1f): 3 aircraft (airframe model) - [Southwest Florida UH-1H](https://openairdocs.org/model/southwest-florida-uh-1h): 3 aircraft (airframe model) - [Bell Helicopter UH-1H (205)](https://openairdocs.org/model/bell-helicopter-uh-1h-205): 3 aircraft (airframe model) - [Richards Heavylift Helo UH-1H](https://openairdocs.org/model/richards-heavylift-helo-uh-1h): 2 aircraft (airframe model) - [Hawkins & Powers UH-1B](https://openairdocs.org/model/hawkins-powers-uh-1b): 2 aircraft (airframe model) - [Arrow Falcon Exporters UH-1H](https://openairdocs.org/model/arrow-falcon-exporters-uh-1h): 2 aircraft (airframe model) - [Garlick Helicopters HH-1K](https://openairdocs.org/model/garlick-helicopters-hh-1k): 2 aircraft (airframe model) - [Rotorcraft Development UH-1H](https://openairdocs.org/model/rotorcraft-development-uh-1h): 2 aircraft (airframe model) - [Western International Avia UH-1H](https://openairdocs.org/model/western-international-avia-uh-1h): 2 aircraft (airframe model) - [Bell HH-1K](https://openairdocs.org/model/bell-hh-1k): 1 aircraft (airframe model) - [Bell UH-1L](https://openairdocs.org/model/bell-uh-1l): 1 aircraft (airframe model) - [Bell-Colonial UH-1B](https://openairdocs.org/model/bell-colonial-uh-1b): 1 aircraft (airframe model) - [Bell-Sw Florida Avn UH-1B](https://openairdocs.org/model/bell-sw-florida-avn-uh-1b): 1 aircraft (airframe model) - [Southwest Florida SW204HP](https://openairdocs.org/model/southwest-florida-sw204hp): 1 aircraft (airframe model) - [Precision Helicopters UH-1H](https://openairdocs.org/model/precision-helicopters-uh-1h): 1 aircraft (airframe model) All 22 models: https://openairdocs.org/ad/2002-20-01/models.md Every aircraft: https://openairdocs.org/ad/2002-20-01/aircraft.md ## Related documents - [Proposed rule 2001-SW-41-AD](https://openairdocs.org/proposed/2001-SW-41-AD): Notice of proposed rulemaking (NPRM), published Apr 10, 2002 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.