AD 94-24-11

This amendment adopts a new airworthiness directive (AD), applicable to Bell Helicopter Textron, Inc. Model 206A, 206B, 206L, 206L-1, and 206L-3 helicopters, that requires a one-time inspection for cracks in the tail rotor drive shaft hanger bearing support brackets (brackets), and repair or replacement, as necessary. This amendment is prompted by reports of cracks in the bend radius of the brackets. The actions specified by this AD are intended to prevent misalignment of the tail rotor drive shaft, failure of the tail rotor drive shaft system, loss of control of the tail rotor, and subsequent loss of control of the helicopter.

Final rule

94-24-11 BELL HELICOPTER TEXTRON, INC. (BHTI): Amendment 39-9084. Docket No. 93-SW-15-AD.

Applicability: Model 206A and 206B helicopters, with tail rotor drive shaft hanger bearing support brackets (brackets), part number (P/N) 206-030-407 or -433, installed; and Models 206L, 206L-1, and 206L-3 helicopters, with brackets, P/N 206-033-412, installed, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent misalignment of the tail rotor drive shaft, failure of the tail rotor drive shaft system, loss of control of the tail rotor, and subsequent loss of control of the helicopter, accomplish the following:

(a) Within the next 100 hours time-in-service after the effective date of this AD, and prior to installing any affected brackets on a helicopter, accomplish the following:

(1) Inspect and rework brackets, P/N 206-030-407 or -433, in accordance with the Accomplishment Instructions of BHTI Alert Service Bulletin (ASB) No. 206-92-69, dated September 29, 1992.

(2) Inspect and rework brackets, P/N 206-033-412, in accordance with the Accomplishment Instructions of BHTI ASB 206L-92-84, dated September 29, 1992.

(b) If multiple cracks are found, or if a crack is found that equals or exceeds 0.10 inches in length, replace the bracket before further flight.

(c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used when approved by the Manager, Rotorcraft Certification Office, FAA, Southwest Region, Rotorcraft Directorate, Fort Worth, Texas 76193- 0170. 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: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Rotorcraft Certification Office.

(d)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.

(e) The inspections, rework, and replacement, if necessary, shall be done in accordance with BHTI Alert Service Bulletin 206-92-69, dated September 29, 1992, that is applicable to BHTI Model 206A and 206B helicopters; and BHTI Alert Service Bulletin 206L- 92-84, dated September 29, 1992, that is applicable to BHTI Model 206L, 206L-1, and 206L-3 helicopters. 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, Inc., P.O. Box 482, Customer Support, Fort Worth, Texas 76101. Copies may be inspected at the FAA, Office of the Assistant Chief Counsel, 2601 Meacham Boulevard, Room 663, Fort Worth, Texas; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(f) This amendment becomes effective on January 6, 1995.

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 Bell Helicopter Textron, Inc. Model 206A, 206B, 206L, 206L-1, and 206L-3 helicopters was published in the Federal Register on September 21, 1993 (58 FR 48989). That action proposed to require a one-time inspection for cracks of tail rotor drive shaft hanger bearing support brackets (brackets), and repair or replacement, as necessary.

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. However, in the cost/benefit analysis section of the preamble, the average labor rate has been changed from the proposed rate of $55 per work hour to the more current rate of $60 per work hour. This rate change increases the proposed estimated total cost of $1,265,000 by $55,000to $1,320,000. Additionally, there have been some editorial changes made to the proposal. The FAA has determined that air safety and the public interest require the adoption of the rule as proposed with the changes noted. Although the labor rate and, correspondingly, the estimated total cost amounts have been changed to reflect the more current labor rate, these changes have been made to the preamble information and not to the proposed regulatory requirements of the AD. The FAA has determined that the editorial changes made to the regulatory requirements of the rule will neither increase the economic burden on any operator nor increase the scope of the AD.

The FAA estimates that 5,500 helicopters of U.S. registry will be affected by this AD, that it will take approximately 2 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 $120 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $1,320,000.

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. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89.

39.13 - [Amended]
2. Section 39.13 is amended by adding a new airworthiness directive to read as follows: