AD 94-13-04

This amendment adopts a new airworthiness directive (AD), applicable to Schweizer Aircraft Corporation and Hughes Helicopters, Inc. Model 269A, 269A-1, 269B, 269C, and TH-55A series helicopters, that requires mandatory replacement of all the clevis pins associated with the belt drive clutch control installation. This amendment is prompted by an accident involving the separation of the belt drive clutch control spring assembly (spring assembly) from the idler pulley assembly. The actions specified by this AD are intended to prevent separation of the spring assembly from the idler pulley assembly, loss of power to the main rotor system, and a subsequent forced landing.

Final rule

94-13-04 SCHWEIZER AIRCRAFT CORPORATION AND HUGHES HELICOPTERS, INC.: Amendment 39-8944. Docket Number 93-SW-09-AD.

Applicability: Model 269A, 269A-1, 269B, and TH-55A series helicopters, and Model 269C series helicopters with serial numbers (S/N) prior to S/N 1632, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent separation of the belt drive clutch control spring assembly (spring assembly) from the idler pulley assembly, loss of power to the main rotor system, and a subsequent forced landing, accomplish the following:

(a) Within the next 400 hours' time-in-service, or on or before 30 days after the effective date of this AD, whichever comes first, replace the clevis pins in the spring assembly with bolts in accordance with Part II of Schweizer Aircraft Corporation Service Bulletin B-256.2, dated June 11, 1993.

(b) 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, New York Aircraft Certification Office, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, New York Aircraft Certification Office.

NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the New York Aircraft Certification Office.

(c) 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.

(d) The replacement shall be done in accordance with Schweizer Aircraft Corporation Service Bulletin B-256.2, dated June 11, 1993. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1CFR Part 51. Copies may be obtained from Schweizer Aircraft Corporation, P.O. Box 147, Elmira, New York 14902. 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.

(e) This amendment becomes effective September 1, 1994.

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 Schweizer Aircraft Corporation and Hughes Helicopters, Inc. Model 269A, 269A-1, 269B, 269C, and TH-55A series helicopters was published in the Federal Register on August 4, 1993 (58 FR 41444). That action proposed to require replacement of all clevis pins associated with the belt drive clutch control installation.

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 with one change. The AD proposed compliance on or before January 13, 1994, or within the next 400 hours' time-in-service (TIS), whichever comes first. Since January 13, 1994, has passed, theAD has been changed to now require compliance within 30 days after the effective date of the AD or within 400 hours' TIS, whichever comes first.

The FAA estimates that 1,100 helicopters of U.S. registry will be affected by this AD, that it will take approximately work hour per helicopter to accomplish the required actions, and that the average labor rate is $55 per work hour. Required parts will cost approximately $10 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $41,250.

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 - AIRWORTHINESSDIRECTIVES
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: