[Federal Register Volume 65, Number 56 (Wednesday, March 22, 2000)]
[Proposed Rules]
[Pages 15280-15282]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-7112]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-SW-37-AD]


Airworthiness Directives; Sikorsky Aircraft Corporation 
(Sikorsky) Model S-76A Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes adopting a new airworthiness directive

[[Page 15281]]

(AD) applicable to Sikorsky Model S-76A helicopters. The AD would 
require inspecting at specified intervals until installing a soft-start 
assembly retrofit kit on the air conditioning system to prevent a 
continuous flow of current through the soft-start resistor. This 
proposal is prompted by a report of overheating of the soft-start 
assembly. The actions specified by the proposed 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.

DATES: Comments must be received on or before May 22, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 99-SW-37-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137. Comments may be inspected at this location 
between 9:00 am and 3:00 pm, Monday through Friday, except Federal 
holidays.
    The service information referenced in the proposed rule may be 
obtained from Sikorsky Aircraft Corporation, Attn: Manager, Commercial 
Tech Support, 6900 Main Street, P.O. Box 9729, Stratford, Connecticut 
06615-9129, phone (203) 386-7860, fax (203) 386-4703. This information 
may be examined at the FAA, Office of the Regional Counsel, Southwest 
Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas.

FOR FURTHER INFORMATION CONTACT: Terry Fahr, Boston Aircraft 
Certification Office, 12 New England Executive Park, Burlington, MA 
01803, telephone (781) 238-7155, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications should identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket No. 99-SW-37-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 99-SW-37-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137.

Discussion

    This document proposes adopting a new AD applicable to Sikorsky 
Model S-76A helicopters. The AD would 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, part number (P/N) S-76A-1-2, in 120 calendar days 
to prevent a continuous flow of current through the soft-start 
resistor. This proposal is prompted by a report of overheating of the 
air conditioning soft-start assembly. This condition, if not corrected, 
could cause serious secondary damage in the lower tailcone, an 
electrical fire, and subsequent loss of control of the helicopter.
    The FAA has reviewed Sikorsky Alert Service Bulletin 76-21-4A, 
dated February 24, 1998 (ASB). The ASB refers operators to procedures 
in Aero Aire Corp. Service Bulletins 970001, Revision A, dated 
September 18, 1997, for inspecting the soft-start assembly, and 970002, 
dated December 18, 1997, for installing a soft-start assembly retrofit 
kit, P/N 76SB001, on the Aero Aire Air Conditioning System, P/N S-76A-
1-2, on Sikorsky Model S-76A helicopters. The ASB states the procedures 
are necessary to prevent overheating of the air conditioning soft-start 
assembly that could cause serious secondary damage in the lower 
tailcone.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other Sikorsky Model S-76A helicopters of the same 
type designs, the proposed AD would require inspecting the soft start 
assembly at intervals not to exceed 25 hours time-in-service until 
installing a soft-start control assembly retrofit kit on the Aero Aire 
Air Conditioning System, P/N A-76A-1-2, within 120 calendar days. The 
actions would be required to be accomplished in accordance with the 
Aero Aire service bulletins described previously.
    The FAA estimates that 9 helicopters of U.S. registry would be 
affected by this proposed AD, that it would take approximately 3 work 
hours per helicopter to accomplish the proposed 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 proposed AD on U.S. 
operators is estimated to be $1620.
    The regulations proposed herein would 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, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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.

[[Page 15282]]

Sec. 39.13  [Amended]

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

Sikorsky Aircraft Corporation:
    Docket No. 99-SW-37-AD.

    Applicability: Model S-76A helicopters with Aero Aire Air 
Conditioning System, part number (P/N) S-76A-1-2, 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 requirements of 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.

    Issued in Fort Worth, Texas, on March 15, 2000.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 00-7112 Filed 3-21-00; 8:45 am]
BILLING CODE 4910-13-U