AD 2000-12-09

This amendment adopts a new airworthiness directive (AD) for Sikorsky Model S-76A helicopters. This AD requires inspecting the air conditioning system at specified intervals until installing a soft-start assembly retrofit kit to prevent a continuous flow of current through the soft-start resistor. This amendment is prompted by a report of overheating of the soft-start assembly. The actions specified by this AD are intended to prevent overheating of the air conditioning soft-start assembly, damage in the lower tailcone, an electrical fire, and subsequent loss of control of the helicopter

Final rule

2000-12-09 SIKORSKY AIRCRAFT CORPORATION: Amendment 39-11787. Docket No. 99-SW-37-AD.
Applicability: Model S-76A helicopters with Aero Aire Air Conditioning System, part number (P/N) S-76A-2, modified in accordance with Supplemental Type Certificate SH4680SW, 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 (c) of this AD. The request should include an assessment of 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 as indicated, unless accomplished previously.

To prevent overheating of the air conditioning soft-start control assembly, damage in the lower tailcone, a fire, and subsequent loss of control of the helicopter, accomplish the following:

(a) Within 25 hours time-in-service (TIS) and thereafter at intervals not to exceed 25 hours TIS, inspect the soft-start control assembly in accordance with the Accomplishment Instruction, Section III, of Aero Aire Corporation Service Bulletin No. 970001, Revision A, dated September 18, 1997, except neither contact nor return of the soft-start controller unit is required.

(b) Within 120 calendar days, install a soft start assembly retrofit kit (kit), P/N 76SB001, in accordance with the Accomplishment Instructions, Section III, of Aero Aire Corporation Service Bulletin 970002, dated December 18, 1997. Installing the kit is terminating action for the requirementsof this AD.

(c) 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, Boston 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, Boston Aircraft Certification Office.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Boston Aircraft 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 inspection shall be done in accordance with the Accomplishment Instruction, Section III, of Aero Aire Corporation Service Bulletin No. 970001, RevisionA, dated September 18, 1997. The modification shall be done in accordance with the Accomplishment Instructions, Section III, of Aero Aire Corporation Service Bulletin 970002, dated December 18, 1997. 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 Sikorsky Aircraft Corporation, Attn: Manager, Commercial Tech Support, 6900 Main Street, P. O. Box 9729, Stratford, Connecticut 06497-9129, phone (203) 386-7860, fax (203) 386-4703. 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.

(f) This amendment becomes effective on July 28, 2000.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD for Sikorsky Model S-76A helicopters was published in the Federal Register on March 22, 2000 (65 FR 15280). That action proposed to require inspecting the soft-start assembly at intervals not to exceed 25 hours time-in-service until installing a soft-start assembly retrofit kit on the Aero Aire Air Conditioning System in 120 calendar days to prevent a continuous flow of current through the soft-start resistor.

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.

The FAA estimates that 9 helicopters of U.S. registry will be affected by this AD, that it will take approximately 3 work hours per helicopter to accomplish the required actions, and that the average labor rate is $60 per work hour. Aero Aire Service Bulletin No. 97002 states that the retrofit kit will be provided at no charge. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $1,620.

The regulations adopted herein will not have a substantial direct effect 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, it is determined that this final rule does not have federalism implications under Executive Order 13132.

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 adding a new airworthiness directive to read as follows: