# AD 98-18-01: Main Rotor Trunnion - Type: Airworthiness directive - Status: Current - Products: Bell Helicopter Textron 214B, 214B-1 and 214ST - Effective: September 29, 1998 - Published: August 25, 1998, 63 FR 45169–45170 - Issued as: Final rule - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Rotorcraft - Amendment: 39-10717 - Docket: 94-SW-29-AD - Registered aircraft: 30 may be affected, by airframe or engine model (OpenAirDocs) - Official PDF: https://openairdocs.org/files/sha256/14/8d/148d81d34f8d3c6e74a7522b1cfb9c29b32f67ce62ec69a7b5772540106b5012 (from https://www.govinfo.gov/content/pkg/FR-1998-08-25/pdf/98-22698.pdf) - Federal Register: https://www.federalregister.gov/documents/1998/08/25/98-22698/airworthiness-directives-bell-helicopter-textron-inc-model-214b-214b-1-and-214st-helicopters - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/655B1B7249DA2D1986256A4D006F69D7.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/98-18-01 ## Summary This amendment supersedes an existing airworthiness directive (AD), applicable to Bell Helicopter Textron, Inc. (BHTI) Model 214B, 214B-1, and 214ST helicopters, that currently establishes a retirement life of 60,000 high-power events for the main rotor trunnion (trunnion). This amendment requires changing the method of calculating the retirement life for the trunnion from high-power events to a maximum accumulated Retirement Index Number (RIN). This amendment is prompted by fatigue analyses and tests that show certain trunnions fail sooner than originally anticipated because of the unanticipated higher number of lifts or takeoffs (torque events) performed with those trunnions. The actions specified by this AD are intended to prevent fatigue failure of the trunnion, which could result in loss of the main rotor and subsequent loss of control of the helicopter. ## The airworthiness directive 98-18-01 BELL HELICOPTER TEXTRON, INC. (BHTI): Amendment 39-10717. Docket No. 94-SW-29-AD. Supersedes AD 94-15-14, Amendment 39-8985, Docket No. 93-SW-20-AD. Applicability: Model 214B, 214B-1, and 214ST helicopters, with main rotor trunnion (trunnion), part number (P/N) 214-010-230-101, 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 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 use the authority provided in paragraph (e) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition, or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any helicopter from the applicability of this AD. Compliance: Required within 25 hours time-in-service (TIS) after the effective date of this AD, unless accomplished previously. To prevent fatigue failure of the trunnion, which could result in loss of the main rotor and subsequent loss of control of the helicopter, accomplish the following: (a) Create a component history card or an equivalent record for the trunnion, P/N 214-040-230-101. (b) Determine and record on a component history card or equivalent record the accumulated Retirement Index Number (RIN) to-date on the trunnion by multiplying the accumulated high-power event total to-date by 2 or as follows: (1) For Model 214B and 214B-1, multiply the flight hour total to-date by 24 (round-up any resulting fraction to the next higher whole number); or (2) For Model 214ST, multiply the factored flight hour total to-date by 24 (round-up any resulting fraction to the next higher whole number). NOTE 2: BHTI Alert Service Bulletin (ASB) No. 214-94-55, which is applicable to Model 214B and 214 B-1 helicopters, and ASB No. 214ST-94-70, which is applicable to Model 214ST helicopters, both dated November 7, 1994, pertain to this AD. (c) After complying with paragraphs (a) and (b) of this AD, during each operation thereafter, maintain a count of the number and type of external load lifts and the number of takeoffs performed and, at the end of each day's operations, increase the accumulated RIN on the component history card as follows: (1) For the Model 214B and 214B-1 helicopters, (i) Increase the RIN by 1 for each takeoff. (ii) Increase the RIN by 1 for each external load lift operation, or increase the RIN by 2 for each external load lift operation in which the load is picked up at a higher elevation and released at a lower elevation, and the difference in elevation between the pickup point and the release point is 200 feet or greater. (2) For the Model 214ST helicopters, (i) Increase the RIN by 2 for each takeoff. (ii) Increase the RIN by 2 for each external load lift operation, or increase the RIN by 4 for each external load lift operation in which the load is picked up at a higher elevation and released at a lower elevation, and the difference in elevation between the pickup point and the release point is 200 feet or greater. (d) Remove the trunnion, P/N 214-010-230-101, from service on or before attaining an accumulated RIN of 120,000. The trunnion is no longer retired based upon flight hours. This AD revises the Airworthiness Limitation section of the maintenance manual by establishing a new retirement life for the trunnion of 120,000 RIN. (e) 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, FAA, Rotorcraft Directorate. 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 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Rotorcraft Certification Office. (f) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the helicopter to a location where the requirements of this AD can be accomplished. (g) This amendment becomes effective on September 29, 1998. ## Rule preamble ### Supplementary information A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 94-15-14, Amendment 39-8985 (59 FR 40798, August 10, 1994), which is applicable to BHTI Model 214B, 214B-1, and 214ST helicopters, was published in the Federal Register on December 12, 1996 (61 FR 65367). That action proposed to require creation of a component history card using the RIN system; a system for tracking increases to the accumulated RIN; and proposed to establish a maximum accumulated RIN for the trunnion of 120,000 at which time the trunnion must be removed from service. Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposal or the FAA's determination of the cost to the public. The FAA has determined that air safety and the public interest require the adoption of the rule, with one non-substantive change. The model 214B-1 has been added to paragraph (b)(1) of the AD to explicitly state that the accumulated RIN is calculated the same for both Model 214B and 214B-1 helicopters. The FAA has determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD. The FAA estimates that 8 helicopters of U.S. registry will be affected by this AD, that it will take approximately (1) 10 work hours to replace the affected trunnion due to the new method of determining the retirement life required by this AD; (2) 2 work hours per helicopter to create the component history card or equivalent record (record); and (3) 10 work hours per helicopter to maintain the record each year, and that the average labor rate is $60 per work hour. Required parts will cost approximately $11,000 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $17,360 for the first year and $16,520 for each subsequent year. These costs assume replacement of the trunnion in one helicopter each year, creation and maintenance of the records for all the fleet the first year, and creation of one helicopter's records and maintenance of the records for all the fleet each subsequent year. The regulations adopted herein will not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. 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 FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Safety. 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: PART 39 AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. 39.13 [Amended] 2. Section 39.13 is amended by removing Amendment 39-8985 (59 FR 40798, August 10, 1994), and by adding a new airworthiness directive (AD), Amendment 39-10717 to read as follows: ## Affected data sheets (2) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS H6SW](https://openairdocs.org/tcds/H6SW): McDermott 214 Holdings, LLC; names 2 of 2 models: 214B, 214B-1 - [TCDS H10SW](https://openairdocs.org/tcds/H10SW): McDermott 214 Holdings, LLC; names 1 of 1 models: 214ST ## 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: 30 (30 by airframe model, 0 by engine model) - Makers: Bell 29, Bell Helicopter Textron 1 Models with the most aircraft: - [Bell 214ST](https://openairdocs.org/model/bell-214st): 18 aircraft (airframe model) - [Bell 214B-1](https://openairdocs.org/model/bell-214b-1): 9 aircraft (airframe model) - [Bell 214B](https://openairdocs.org/model/bell-214b): 2 aircraft (airframe model) - [Bell Helicopter Textron 214ST](https://openairdocs.org/model/bell-helicopter-textron-214st): 1 aircraft (airframe model) All 4 models: https://openairdocs.org/ad/98-18-01/models.md Every aircraft: https://openairdocs.org/ad/98-18-01/aircraft.md ## Related documents - [Proposed rule 94-SW-29-AD](https://openairdocs.org/proposed/94-SW-29-AD): Notice of proposed rulemaking (NPRM), published Dec 12, 1996 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.