AD 99-17-19

This amendment supersedes an existing airworthiness directive (AD), applicable to Bell Helicopter Textron, A Division of Textron Canada (BHTC), Model 206L, L-1, L-3, and L-4 helicopters, that currently requires the creation of a component history card or equivalent record using the Retirement Index Number (RIN) system for certain mast and trunnions and a system for tracking increases to the accumulated RIN. That AD also establishes retirement lives for the mast and trunnion. This amendment requires the same actions required by the existing AD but increases the RIN multiplier for the mast and corrects a helicopter model number. This amendment is prompted by further tests and analyses that indicate the RIN multiplier for the Model 206L-4 helicopters needs to be increased and the discovery of an error in a model designation in the existing AD. 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.

Final rule

99-17-19 BELL HELICOPTER TEXTRON, A DIVISION OF TEXTRON CANADA: Amendment 39-11265; Docket No. 99-SW-30-AD; Issued August 12, 1999. Supersedes AD 97-07-07, 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 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 (f) of this AD. The request should include an assessmentof 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 within 100 hours time-in-service, 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) Create a component history card or an equivalent record for the affected mast and trunnion.

(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 No. 206L-94-99, Revision A, dated May 1, 1995 (ASB). Record this accumulated RIN on the component history card or equivalent record.

(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 card or equivalent record as follows:

(1) For the trunnion,
(i) Increase the RIN for the Model 206L, 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,
(i) Increase the RIN for the Model 206L, 206L-1, 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.

NOTE 2: Previous Model 206L-4 mast RIN calculations may have increased the RIN by only 1 for each torque event. This AD increases the Model 206L-4 mast RIN by 2 for each torque event.

(d) Remove thetrunnion from service on or before attaining the maximum accumulated RIN (24,000) in accordance with Table 1 of the Accomplishment Instructions of the ASB. This AD revises the Limitations section of the maintenance manual by establishing a retirement life of 24,000 RIN for the trunnion.

(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 the ASB. This AD revises the Limitations section of the maintenance manual by establishing a retirement life of 44,000 RIN for the mast.

(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 appropriate FAA Principal Maintenance Inspector, who may add comments 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.

(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) The determination of the RIN count on the trunnion and mast shall be made in accordance with Bell Helicopter Textron, Inc. Alert Service Bulletin No. 206L-94-99, Revision A, dated May 1, 1995. The incorporation by reference of that document was approved previously by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51, as of May 9, 1997 (62 FR 16073, April 4, 1997). Copies may be obtained from Bell Helicopter Textron, a Division of Textron Canada, 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 Regional Counsel, Southwest Region, 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) This amendment becomes effective on September 24, 1999.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 97-07-07, Amendment 39-9981 (62 FR 16073), applicable to BHTC Model 206L, L-1, L-3, and L-4 helicopters, was published in the Federal Register on May 26, 1999 (64 FR 28418). That action proposed requiring creation of a component history card or equivalent record using a RIN system, establishing a system for tracking increases to the accumulated RIN and establishing a maximum accumulated RIN for certain masts and trunnions. That action also proposed correcting an error in the increase in the RIN count for the Model 206L-4 in paragraph (c)(2), correcting a model number in paragraph (c)(1)(i), and making other nonsubstantive changes to the text.

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 hasdetermined that air safety and the public interest require the adoption of the rule as proposed.

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 of 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 cost impact of the AD on U.S. operators for the first year 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 therecords 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 estimated cost impact amounts are based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

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 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, 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 39-9981 (62 FR 16073, April 4, 1997), and by adding a new airworthiness directive (AD), Amendment 39-11265, to read as follows: