05-11516. 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 Sikorsky Aircraft Corporation (Sikorsky) Model S-92A helicopters. This action requires replacing the main gearbox (MGB) lubrication/scavenge pump vespel spline adapters (vespel spline adapters) before further flight, and thereafter, replacing them at certain intervals. This amendment is prompted by a reported incident of an in-flight loss of oil pressure. The actions specified in this AD are intended to prevent loss of lubrication to the MGB, which could cause failure of one or both engine input drives, or planetary gear to sun gear tooth mesh failure, resulting in loss of power to the rotor system and subsequent loss of control of the helicopter.

DATES:

Effective June 29, 2005.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of June 29, 2005.

Comments for inclusion in the Rules Docket must be received on or before August 15, 2005.

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, FAA, Boston Aircraft Certification Office, 12 New England Executive Park, Burlington, MA 01803, telephone [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

This amendment adopts a new AD for Sikorsky Model S-92A helicopters that have MGB lubrication/scavenge pump, part number (P/N) 92351-15800-101, with vespel spline adapter, P/N 1584000-1, installed. This action requires, before further flight, removing the two vespel spline adapters and replacing them with airworthy vespel spline adapters, and thereafter, replacing them at intervals not to exceed 50 hours time-in-service (TIS). This amendment is prompted by a report of a loss of oil pressure during a flight to an offshore oil rig. Subsequent investigation, which is continuing, reveals that the vespel spline adapter installed on the helicopter failed due to excessive wear. The actions specified in this AD are intended to prevent loss of lubrication to the MGB, which could cause failure of one or both engine input drives, or planetary gear to sun gear tooth mesh failure, resulting in loss of power to the rotor system and subsequent loss of control of the helicopter.

We have reviewed Sikorsky Aircraft Corporation Alert Service Bulletin (ASB) No. 92-63-001, dated April 1, 2005, which describes procedures for removing and replacing the vespel spine adapter. This AD differs from the manufacturer's ASB in that we are incorporating only the necessary portion of the Accomplishment Instructions of the ASB and do not require returning the replaced parts to the manufacturer, nor do we require providing a report to the manufacturer.

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 loss of lubrication to the MGB, which could cause failure of one or both engine input drives, or planetary gear to sun gear tooth mesh failure, resulting in loss of power to the rotor system and subsequent loss of control of the helicopter. This AD requires removing the left-hand and right-hand main lubrication/scavenge pumps to access the vespel spline adapters and removing and replacing the vespel spline adapters before further flight and thereafter, at intervals not to exceed 50 hours TIS. Accomplish the actions in accordance with the ASB described previously.

The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the controllability of the helicopter. Therefore, the initial replacement is required before further flight, and the repetitive replacements are required at intervals not to exceed 50 hours TIS, both of which are very short time periods, 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 4 helicopters of U.S. registry. Replacing both vespel spline adapters will take approximately 3 work hours to accomplish at an average labor rate of $65 per work hour. Required parts will cost approximately $350 for each of the two adapters, however, the manufacturer has stated that they will provide the replacement parts at no charge until the end of the warranty period for the vespel spline adapter. Based on these figures, we estimate the total cost impact of the AD on U.S. operators to be $2,180, assuming that one vespel spline adapter that is not covered by manufacturer's warranty is replaced on each helicopter.

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-2005-21373; Directorate Identifier 2005-SW-13-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:

2005-12-03 Sikorsky Aircraft Corporation: Amendment 39-14119. Docket No. FAA-2005-21373; Directorate Identifier 2005-SW-13-AD.

Applicability: Model S-92A helicopters with main gearbox (MGB) lubrication/scavenge pump, part number (P/N) 92351-15800-101, with vespel spline adapter, P/N 1584000-1, installed, certificated in any category.

Compliance: Required before further flight, unless accomplished previously, and thereafter, at intervals not to exceed 50 hours time-in-service.

To prevent loss of lubrication to the MGB, which could cause failure of one or both engine input drives, or planetary gear to sun gear tooth mesh failure, resulting in loss of power to the rotor system and subsequent loss of control of the helicopter, accomplish the following:

(a) Remove and replace each MGB lubrication/scavenge pump vespel spline adapter in accordance with paragraph 3.A., steps (1) through (6) of the Accomplishment Instructions in Sikorsky Aircraft Corporation Alert Service Bulletin No. 92-63-001, dated April 1, 2005.

(b) 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 Boston Aircraft Certification Office, Engine and Propeller Directorate, FAA, for information about previously approved alternative methods of compliance.

(c) The removals and replacements shall be done in accordance with paragraph 3.A., steps (1) through (6) of the Accomplishment Instructions in Sikorsky Aircraft Alert Service Bulletin No. 92-63-001, dated April 1, 2005. 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.

(d) This amendment becomes effective on June 29, 2005.

Issued in Fort Worth, Texas, on June 1, 2005.

Carl F. Mittag,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.