- Effective
- May 9, 1997
- Published
- April 4, 1997 · 62 FR 16073–16075
- Amendment
- 39-9981
- Docket
- 95-SW-36-AD
- Issued as
- Final rule
Unofficial copy from the Federal Register text, document 97-8425. Only the govinfo PDF is the legal edition.
Copies of the files this page was built from, with their SHA-256. Retrieved October 18, 2026.
| File | Size | SHA-256 | Original |
|---|---|---|---|
| Official PDF | 125 KB | 484bd882…223a3f0 | 97-8425.pdf on govinfo.gov |
| Federal Register text | 12 KB | c7b86261…b05f705 | 97-8425.txt on federalregister.gov |
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Summary
This amendment adopts a new airworthiness directive (AD), applicable to Bell Helicopter Textron, A Division of Textron Canada Ltd. (BHTC) Model 206L, L-1, L-3, and L-4 helicopters, that requires creation of a component history card using a Retirement Index Number (RIN) system, establishing a system for tracking increases to the accumulated RIN, and a maximum accumulated RIN for certain main rotor masts (masts) and main rotor trunnions (trunnions). This amendment is prompted by fatigue analyses and tests that show certain masts and trunnions fail sooner than originally anticipated because of the unanticipated higher number of external load lifts and takeoffs (torque events) performed with those masts and trunnions in addition to the time-in-service (TIS) accrued under other operating conditions. The actions specified by this AD are intended to prevent fatigue failure of the mast or trunnion, which could result in loss of the main rotor system and subsequent loss of control of the helicopter.
The airworthiness directive
Sec. 39.13 [Amended]
PDF page 22. Section 39.13 is amended by adding a new airworthiness directive to read as follows:
AD 97-07-07 Bell Helicopter Textron, a Division of Textron Canada Ltd.: Amendment 39-9981. Docket No. 95-SW-36-AD.
Applicability: Model 206L, 206L-1, 206L-3, and 206L-4 helicopters, with main rotor mast (mast), part number (P/N) 206-040-535-001, -005, -101, or -105, installed, or main rotor trunnion (trunnion), P/N 206-011-120-103, 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 (f) 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 100 hours time-in-service after the effective date of this AD, unless accomplished previously.
To prevent fatigue failure of the mast or trunnion, which could result in loss of the main rotor system and subsequent loss of control of the helicopter, accomplish the following:
(a)
PDF page 3(a) Create a component history card or an equivalent record for the affected mast and trunnion.
(b)
PDF page 3(b) Determine the accumulated Retirement Index Number (RIN) to date based on the number of takeoffs and external load lifts (torque events) for parts in service in accordance with paragraphs 1 and 2 of the Accomplishment Instructions of Bell Helicopter Textron, Inc. Alert Service Bulletin (ASB) No. 206L-94-99, Revision A, dated May 1, 1995. Record this accumulated RIN on the component history card.
(c)
PDF page 3(c) After complying with paragraphs (a) and (b) of this AD, during each operation thereafter, maintain a count of the number 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 cards as follows:
(1) For the trunnion,
(i) Increase the RIN for the Model 206, 206L-1, and 206L-3 helicopters by 1 for each torque event.
(ii) Increase the RIN for the Model 206L-4 helicopters by 2 for each torque event.
(2) For the mast, increase the RIN for the Model 206L, 206L-1, 206L-3, and 206L-4 helicopters by 1 for each torque event.
(d)
PDF page 3(d) Remove the trunnion from service on or before attaining the maximum accumulated RIN (24,000) in accordance with Table 1 of the Accomplishment Instructions of Bell Helicopter Textron, Inc. ASB No. 206L-94-99, Revision A, dated May 1, 1995.
(e)
PDF page 3(e) Remove the mast from service on or before attaining the maximum accumulated RIN (44,000) or the flight hour service life limit, whichever occurs first, in accordance with Table 2 of the Accomplishment Instructions of Bell Helicopter Textron, Inc. ASB No. 206L-94-99, Revision A, dated May 1, 1995.
(f)
PDF page 3(f) 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.
(g)
PDF page 3(g) 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.
(h)
PDF page 3(h) The creation of the component history card, documentation, and removal of the trunnion and mast shall be done in accordance with Bell Helicopter Textron, Inc. ASB No. 206L-94-99, Revision A, dated May 1, 1995. This 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 Bell Helicopter Textron, A Division of Textron Canada Ltd. 12,800 Rue de L'Avenir, Mirabel, Quebec, Canada J7J1R4, ATTN: Product Support Engineering Light Helicopters. Copies may be inspected at the FAA, Office of the Assistant Chief Counsel, 2601 Meacham Blvd., Room 663, Fort Worth, Texas; or at the Office of the Federal Register, 800 North Capitol Street, NW., Suite 700, Washington, DC.
(i)
PDF page 3(i) This amendment becomes effective on May 9, 1997.
Issued in Fort Worth, Texas, on March 14, 1997. Eric Bries, Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
Rule preamble
The FAA’s background, reasoning and cost estimate, published with the AD.
DatesPage 2
Effective May 9, 1997.
The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of May 9, 1997.
AddressesPage 2
The service information referenced in this AD may be obtained from Bell Helicopter Textron, A Division of Textron Canada Ltd. 12,800 Rue de L'Avenir, Mirabel, Quebec, Canada J7J1R4, ATTN: Product Support Engineering Light Helicopters. This information may be examined at the FAA, Office of the Assistant Chief Counsel, 2601 Meacham Blvd., Room 663, Fort Worth, Texas; or at the Office of the Federal Register, 800 North Capitol Street, NW., Suite 700, Washington, DC.
For further information contactPage 2
Mr. Jurgen Priester, Aerospace Engineer, Rotorcraft Certification Office, Rotorcraft Directorate, FAA, 2601 Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5159, fax (817) 222-5959.
Supplementary informationPage 2
A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to BHTC Model 206L, 206L-1, 206L-3, and 206L-4 helicopters was published in the Federal Register on November 14, 1996 (61 FR 58355). That action proposed to require, within the next 100 hours TIS, creation of a component history card using the RIN system for certain masts and trunnions; and establishing a system for tracking increases to the accumulated RIN. That action also proposed to establish a retirement life for trunnions based solely on a RIN of 24,000, and a mast retirement life based on a maximum RIN of 44,000 or a maximum number of flight hours, whichever occurs first.
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 as proposed, except for the parenthetical insertion of the number of RIN's in paragraphs (d) and (e). The FAA has determined that this change will neither increase the economic burden on any operator nor expand the scope of the AD.
The FAA estimates that 711 helicopters of U.S. registry will be affected by this AD, that it will take approximately (1) 8 work hours per helicopter to replace the mast and 10 work hours per helicopter to replace the 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); (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 $9,538 per mast and $2,083 per trunnion. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $2,016,989, and each subsequent year to be $1,945,889. These costs assume replacement of the mast and trunnion in one-sixth of the fleet each year, creation and maintenance of the records for all the fleet the first year, and creation of one-sixth of the fleet'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 location provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39Page 2
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the AmendmentPage 2
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:
Adoption of the amendmentPage 2
1. The authority citation for part 39 continues to read as follows:
Authority: 49 USC 106(g), 40113, 44701.