2011-27659. Airworthiness Directives; Sikorsky Aircraft Corporation Model S-76A Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes adopting a new airworthiness directive (AD) for the Sikorsky Aircraft Corporation (Sikorsky) Model S-76A helicopters. This proposal would require modifying the electric rotor brake (ERB). Thereafter, the AD would also require inserting changes to the “Normal Procedures” and “Emergency Procedures” sections of the Rotorcraft Flight Manual (RFM), which revises the information of the basic RFM when the ERB is installed. This proposal is prompted by a reported incident of a fire occurring in an ERB installed on a Model S-76A helicopter. The actions specified by this proposed AD are intended to prevent overheating of the ERB assembly, ignition of the ERB hydraulic fluid, a fire in the main gearbox area, and subsequent loss of control of the helicopter.

DATES:

Comments must be received on or before December 27, 2011.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
• Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

You may get the service information identified in this proposed AD from Sikorsky Aircraft Corporation, Attn: Manager, Commercial Technical Support, mailstop s581a, 6900 Main Street, Stratford, CT, telephone [phone], e-mail address: [e-mail], or at http://www.sikorsky.com.

FOR FURTHER INFORMATION CONTACT:

Caspar Wang, Aviation Safety Engineer, Boston Aircraft Certification Office, 12 New England Executive Park, Burlington, MA 01803, telephone [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any written data, views, or arguments regarding this proposed AD. Send your comments to the address listed under the caption ADDRESSES. Include the docket number “FAA-2010-0517, Directorate Identifier 2009-SW-73-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed rulemaking. Using the search function of our docket Web site, you can find and read the comments to any of our dockets, including the name of the individual who sent or signed the comment. You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78).

Examining the Docket

You may examine the docket that contains the proposed AD, any comments, and other information on the Internet at http://www.regulations.gov or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Operations office (telephone [phone]) is located in Room W12-140 on the ground floor of the West Building at the street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

Discussion

A number of service documents and ADs have been issued relating to the ERB on these and similar model helicopters. AD 82-17-03, issued July 30, 1982 (47 FR 35469, August 16, 1982), requires a puck-to-disc inspection of rotor brake, part number (P/N) 76363-09101-101, and modification of the ERB system including, among other modifications, installation of a warning relay by following Sikorsky Customer Service Bulletin No. 76-66-10B, dated November 25, 1981. AD 2003-04-15, issued February 14, 2003 (68 FR 8994, February 27, 2003), requires inspecting certain rotor brake discs for cracks that resulted from improper heat treating of the disc. This document proposes adopting a new AD for the Sikorsky Model S-76A helicopters with a different part-numbered ERB. This proposal would require, within 120 days, modifying the ERB by installing and operationally testing the parts contained in an ERB warning relay kit (P/N 76070-55023-011), an ERB circuit modification kit (P/N 76070-55033-012), and an ERB modification kit (P/N 76070-55207-011) for helicopters with ERB, P/N 76363-09100-012. This proposal is prompted by a reported incident of a fire occurring in an ERB installed on a Model S-76A helicopter in Brazil. The actions specified by this proposed AD are intended to prevent overheating of the ERB assembly, ignition of the ERB hydraulic fluid, a fire in the main gearbox area, and subsequent loss of control of the helicopter.

We have reviewed the following documents from Sikorsky:

• Customer Service Bulletin No. 76-66-10B, Revision 1, pages 2-8, dated July 30, 1981, and Revision 2, pages 1 and 9-13 dated November 25, 1981 (CSB), specifies installing an ERB warning relay kit;
• Customer Service Notice 76-113, dated June 1, 1983 (CSN), which specifies installing an ERB circuit breaker and modification kit; and
• ASB No. 76-66-48B, Revision B, dated July 8, 2009, which specifies a one-time installation of an ERB modification kit containing two other kits and several modifications.
• RFM Supplement No. 41, dated September 6, 2005, which revises the information in the basic RFM normal and emergency procedures sections when the ERB system is modified.

This unsafe condition is likely to exist or develop on other helicopters of the same type design. Therefore, the proposed AD would require modifying the ERB by installing the parts contained in a warning relay system modification kit, part number (P/N) 76070-55023-011; a circuit modification kit, P/N 76070-55033-012; and a manifold, relay box, junction box, right-hand relay panel, and wiring harness modification kit, P/N 76070-55207-011. The proposed AD would also require operationally testing the ERB system after each modification. The proposed AD would also require inserting changes contained in a supplement into the RFM.

These actions would be required to be accomplished in accordance with specified portions of the service information described previously.

We estimate that this proposed AD would affect 180 helicopters of U.S. registry. It would take about 38 work hours per helicopter to perform the modifications and operational tests at an average labor rate of $85 per work hour. Required parts would cost $13,300 per helicopter. Based on these figures, we estimate the total cost impact of the proposed AD on U.S. operators would be $2,975,400 for the fleet.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. Additionally, this proposed AD would 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.

For the reasons discussed above, I certify that the 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. 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.

We prepared a draft economic evaluation of the estimated costs to comply with this proposed AD. See the AD docket to examine the draft economic evaluation.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• 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.

§ 39.13

[Amended]

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

Sikorsky Aircraft Corporation: Docket No. FAA-2010-0517; Directorate Identifier 2009-SW-73-AD.

Applicability: Model S-76A helicopters, with an electric rotor brake (ERB), part number (P/N) 76363-09100-012, installed, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent overheating of the ERB assembly, ignition of the ERB hydraulic fluid, fire in the main gearbox area, and subsequent loss of control of the helicopter, do the following:

(a) Within 120 days, modify the ERB by installing:

(1) Warning relay system parts contained in modification kit, part number (P/N) 76070-55023-011, and operationally testing the ERB system in accordance with paragraphs 2.A. through 2.F., of Sikorsky Customer Service Bulletin No. 76-66-10B, Revision 1 (pages 2 through 8), dated July 30, 1981, and Revision 2, (pages 1 and 9 through 13) dated November 25, 1981;

(2) Circuit breaker and diodes contained in ERB circuit modification kit, P/N 76070-55033-012, and operationally testing the ERB system in accordance with paragraph B. through F. of Sikorsky Customer Service Notice 76-113, dated June 1, 1983; and

(3) Manifold, relay box, junction box, right-hand relay panel, and wiring harness parts contained in ERB modification kit, P/N 76070-55207-011, and operationally testing the ERB system in accordance with paragraphs 3.B. through 3.I. of the Accomplishment Instructions of Sikorsky Alert Service Bulletin No. 76-66-48B, Revision B, dated July 8, 2009.

(b) After accomplishing paragraph (a) of this AD, insert into the Sikorsky Rotorcraft Flight Manual (RFM) the changes to the “Normal Procedures (Part I, Section II)” and “Emergency Procedures (Part 1, Section III)” contained in Sikorsky RFM, Supplement No. 41, dated September 6, 2005.

(c) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Contact the Manager, Boston Aircraft Certification Office, FAA, ATTN: Caspar Wang, Aviation Safety Engineer, 12 New England Executive Park, Burlington, MA 01803, telephone [phone], fax [phone], for information about previously approved alternative methods of compliance.

(d) The Joint Aircraft System/Component (JASC) Code is 6321: Main Rotor Brake.

Issued in Fort Worth, Texas, on October 7, 2011.

Lance T. Gant,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.