06-4911. Airworthiness Directives; Sikorsky Aircraft Corporation Model S-92A Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This amendment adopts a new airworthiness directive (AD) for the specified Sikorsky Aircraft Corporation (Sikorsky) Model S-92A helicopters. This action requires inspecting each main transmission assembly mounting bolt (bolt) for wear or corrosion, and if wear or corrosion is found, replacing the bolt, bolt barrel nut, and cage. This amendment is prompted by a report of a failure of a bolt that was discovered during a routine maintenance inspection. The actions specified in this AD are intended to prevent failure of a bolt, which could result in loss of support of the main transmission and subsequent loss of control of the helicopter.

DATES:

Effective June 15, 2006.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of June 15, 2006.

Comments for inclusion in the Rules Docket must be received on or before July 31, 2006.

ADDRESSES:

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

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically;
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically;
• Mail: Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590;
• Fax: [phone]; or
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

You may get the service information identified in this AD from Sikorsky Aircraft Corporation, Attn: Manager, Commercial Tech Support, 6900 Main Street, Stratford, Connecticut 06614, phone [phone], fax [phone].

Examining the Docket

You may examine the docket that contains the AD, any comments, and other information on the Internet at http://dms.dot.gov, or in person at the Docket Management System (DMS) Docket Offices between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone [phone]) is located on the plaza level of the Department of Transportation Nassif Building at the street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the DMS receives them.

FOR FURTHER INFORMATION CONTACT:

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

SUPPLEMENTARY INFORMATION:

This amendment adopts an AD for Sikorsky Model S-92A helicopters with bolts, part number SS5211-10-47, installed. This action requires opening the No. 1 and No. 2 engine work platforms to gain access to the bolts and inspecting each of the 8 bolts for wear or corrosion. The inspections for wear or corrosion are required within 100 hours time-in-service (TIS), unless accomplished within the last 500 hours TIS. This action also requires, before further flight, replacing any bolt on which wear or corrosion is found, together with the bolt barrel nut and cage. This amendment is prompted by a report of a bolt failure, which was discovered during a routine 1,250-hours TIS maintenance inspection. Subsequent investigation and analysis of the failed bolt revealed damage from wear and corrosion. The actions specified in this AD are intended to prevent failure of a bolt, which could result in loss of support of the main transmission and subsequent loss of control of the helicopter.

We have reviewed Sikorsky Alert Service Bulletin (ASB) No. 92-63-003, dated February 1, 2006, which describes inspecting the 8 bolts to verify that each bolt has the correct torque, as well as inspecting for wear or corrosion on the bolt, and replacing any bolt on which wear or corrosion is discovered, together with the bolt barrel nut and cage. The ASB also describes reporting the condition of any damaged bolt and returning any removed hardware to Sikorsky. This AD does not require verifying that each bolt has the correct torque, reporting the bolt torque or bolt damage information, nor returning the hardware to Sikorsky. Sikorsky plans to make available a redesigned bolt that should eliminate the fretting that leads to corrosion and subsequent failure of the bolt. In light of that information, we anticipate that we will later issue further AD action to require repetitive inspections at intervals of 500 hours TIS until that bolt is made available by Sikorsky and is installed on helicopters.

This unsafe condition is likely to exist or develop on other helicopters of the same type design. Therefore, this AD is being issued to prevent failure of a bolt, which could result in loss of support of the main transmission and subsequent loss of control of the helicopter. Accomplish the actions by following the specified portions of the ASB described previously. The short compliance time is required because the previously described critical unsafe condition can adversely affect the structural integrity and controllability of the helicopter. Since the fleet has helicopters accruing 8 to 10 hours TIS per day, those helicopters could accrue 100 hours TIS in approximately 2 weeks of operation. Therefore, inspecting each bolt for wear or corrosion is required within 100 hours TIS and replacing any bolt on which wear or corrosion is found, as well as replacing the bolt barrel nut and cage, are required before further flight, and this AD must be issued immediately.

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

We estimate that this AD will affect 8 helicopters, and the inspections for wear or corrosion will take approximately 3.5 work hours to accomplish at an average labor rate of $80 per work hour. Required parts will cost approximately $197 for each bolt, $28 for each bolt barrel nut, and $4 for each cage. Based on these figures, we estimate the total cost impact of the AD on U.S. operators to be $4,072 per helicopter, assuming that replacing 8 bolts, 8 bolt barrel nuts, and 8 cages is necessary.

Comments Invited

This AD is a final rule that involves requirements that affect flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any written data, views, or arguments regarding this AD. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2006-24875; Directorate Identifier 2006-SW-03-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD. We will consider all comments received by the closing date and may amend the AD in light of those comments.

We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this AD. 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 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), or you may visit http://dms.dot.gov.

Regulatory Findings

We have determined that this AD will not have federalism implications under Executive Order 13132. This AD 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.

For the reasons discussed above, I certify that the 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 an economic evaluation of the estimated costs to comply with this AD. See the DMS to examine the 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

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:

2006-11-14 Sikorsky Aircraft Corporation: Amendment 39-14618. Docket No. FAA-2006-24875; Directorate Identifier 2006-SW-03-AD.

Applicability

Model S-92A helicopters, with main transmission mounting bolt (bolt), part number (P/N) SS5211-10-47, installed, certificated in any category.

Compliance

Required as indicated.

To prevent failure of a bolt, which could result in loss of support of the main transmission and subsequent loss of control of the helicopter, accomplish the following:

(a) Within 100 hours time-in-service (TIS), unless accomplished within the last 500 hours TIS, open the No. 1 and No. 2 engine work platforms to gain access to the 8 bolts. Remove each bolt, one at a time, and visually inspect the bolt shank and threads for wear or corrosion in accordance with paragraphs 3.A.(6)(a) of the Accomplishment Instructions in Sikorsky Aircraft Corporation Alert Service Bulletin No. 92-63-003, dated February 1, 2006 (ASB). Reporting the condition of the mounting bolt, tagging the mounting bolt with location, and sending the removed mounting bolt and barrel nut to Sikorsky Aircraft Corporation are not required to satisfy the requirements of this AD.

(b) Before further flight, replace any bolt on which wear or corrosion is found, as well as the bolt barrel nut and cage, with an airworthy bolt, P/N SS5211-10-47, barrel nut, P/N RMLH2577-108, and cage, P/N NAS578-10B.

(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, Engine and Propeller Directorate, FAA, ATTN: Wayne Gaulzetti, 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 inspections shall be done in accordance with the specified paragraphs of Sikorsky Aircraft Corporation Alert Service Bulletin No. 92-63-003, dated February 1, 2006. The Director of the Federal Register approved this incorporation by reference 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, Stratford, Connecticut 06614, phone [phone], fax [phone]. Copies may be inspected at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html.

(e) This amendment becomes effective on June 15, 2006.

Issued in Fort Worth, Texas, on May 18, 2006.

Judy I. Carl,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.