Airworthiness Directives; Pratt & Whitney Canada PT6B-36A and PT6B-36B Turboshaft Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for Pratt & Whitney Canada (PWC) PT6B-36A and PT6B-36B turboshaft engines with compressor rear hubs, part number (P/N) 3018111 installed. This AD requires reviewing, and correcting if necessary the critical part record for compressor rear hubs, P/N 3018111. This AD also requires removing compressor rear hubs from service that exceed the published part life limit, before further flight. This AD results from the discovery of a compressor rear hub, P/N 3018111, that exceeded the published life limit. This occurred because the operator used an incorrect life limit calculation contained in a PWC Service Bulletin. We are issuing this AD to prevent uncontained failure of the compressor rear hub and damage to the airplane.

DATES:

Effective October 18, 2004. The Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulations as of October 18, 2004.

We must receive any comments on this AD by November 30, 2004.

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 20590-001.
• Fax: (202) 493-2251.
• 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 can get the service information identified in this AD from Pratt & Whitney Canada, 1000 Marie-Victorin, Longueuil, Quebec, Canada J4G1A1. This information may be examined at the Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-001, on the internet at http://dms.dot.gov ; or 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.

You may examine the comments on this AD in the AD docket on the Internet at http://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT:

Ian Dargin, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-7178; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Transport Canada, which is the airworthiness authority for Canada, recently notified us that an unsafe condition might exist on PWC PT6B-36A and PT6B-36B turboshaft engines. Transport Canada advises that a compressor rear hub, P/N 3018111, was discovered that exceeded the published life limit. This occurred because the operator used an incorrect life limit calculation. PWC investigated and confirmed that PWC Service Bulletin (SB) No. 11002, Original issue-through-Revision 7, incorrectly listed the Flight Count Factor (FCF) of 1 for compressor rear hubs, P/N 3018111. The correct FCF for that part is 3.

Relevant Service Information

We have reviewed and approved the technical contents of PWC SB No. 11002, Revision 8, dated June 11, 2003, that provides the service life limit and correct FCF for compressor rear hubs P/N 3018111. Transport Canada classified this service bulletin as mandatory and issued AD CF-2003-16, dated June 27, 2003, to ensure the airworthiness of these PT6B-36A and PT6B-36B turboshaft engines in Canada.

Bilateral Airworthiness Agreement

These PWC PT6B-36A and PT6B-36B turboshaft engines are manufactured in Canada and are type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Under this bilateral airworthiness agreement, Transport Canada kept the FAA informed of the situation described above. We have examined the findings of Transport Canada, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

FAA's Determination and Requirements of This AD

The unsafe condition described previously is likely to exist or develop on other PWC PT6B-36A and PT6B-36B turboshaft engines of the same type design. We are issuing this AD to prevent uncontained failure of the compressor rear hub and damage to the airplane. This AD requires reviewing, and correcting if necessary the critical part record for compressor rear hubs, P/N 3018111. This AD also requires removing compressor rear hubs from service that exceed the published part life limit, before further flight. You must use the service information described previously to perform the actions required by this AD.

FAA's Determination of the Effective Date

Since an unsafe condition exists that requires the immediate adoption of this AD, we have found that notice and opportunity for public comment before issuing this AD are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

Docket Management System (DMS)

We have implemented new procedures for maintaining AD dockets electronically. As of May 17, 2004, we post new AD actions on the DMS and assign a DMS docket number. We track each action and assign a corresponding Directorate identifier. The DMS docket No. is in the form “Docket No. FAA-200X-XXXXX.” Each DMS docket also lists the Directorate identifier (“Old Docket Number”) as a cross-reference for searching purposes.

Comments Invited

This AD is a final rule that involves requirements affecting flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any written relevant data, views, or arguments regarding this AD. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. FAA-2004-19170; Directorate Identifier 2004-NE-18-AD” in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify it.

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 the DMS web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). 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.

We are reviewing the writing style we currently use in regulatory documents. We are interested in your comments on whether the style of this document is clear, and your suggestions to improve the clarity of our communications with you. You can get more information about plain language at http://www.faa.gov/language and http://www.plainlanguage.gov.

Examining the AD Docket

You may examine the docket that contains the AD, any comments received, and any final disposition in person at the DMS Docket Offices between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone (800) 647-5227) is located on the plaza level of the Department of Transportation Nassif Building at the street address stated in ADDRESSES. Comments will be available in the AD docket shortly after the DMS receives them.

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 a summary of the costs to comply with this AD and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES.

List of Subjects in 14 CFR Part 39

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

Adoption of the Amendment

Under the authority delegated to me by the Administrator, the FAA 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.

2. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

2004-20-04 Pratt & Whitney Canada: Amendment 39-13809. Docket No. FAA-2004-19170; Directorate Identifier 2004-NE-18-AD.

Effective Date

(a) This AD becomes effective October 18, 2004.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Pratt & Whitney Canada (PWC) PT6B-36A and PT6B-36B turboshaft engines with compressor rear hubs, part number (P/N) 3018111 installed. These engines are installed on, but not limited to, Sikorsky S-76B helicopters.

Unsafe Condition

(d) This AD results from results from the discovery of a compressor rear hub, P/N 3018111, that exceeded the published life limit. This occurred because the operator used an incorrect life limit calculation contained in a PWC Service Bulletin. We are issuing this AD to prevent uncontained failure of the compressor rear hub and damage to the helicopter.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.

(f) Within 30 days or at the next engine shop visit, whichever occurs first after the effective date of this AD, do the following:

(1) Using the Flight Count Factor of 3, review and correct the critical part record for compressor rear hubs, P/N 3018111. Use paragraph 3 of the Accomplishment Instructions of PWC Service Bulletin (SB) No. PT6B-72-11002, Revision 8, dated June 11, 2003, to do this.

(2) Remove the compressor rear hub from service before further flight, if its life limit is found to be at or higher than the published life limit in PWC SB No. PT6B-72-11002, Revision 8, dated June 11, 2003.

Alternative Methods of Compliance

(g) The Manager, Engine Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19.

Special Flight Permits

(h) Under 14 CFR part 39.23, we are limiting the special flight permits for this AD by allowing the engine to operate an additional 25 cycles-in-service or 25 operating hours, whichever occurs first, for moving the helicopter to a location where the requirements of this AD can be done.

Material Incorporated by Reference

(i) You must use Pratt & Whitney Canada Service Bulletin No. PT6B-72-11002, Revision 8, dated June 11, 2003, to perform the reviews and corrections required by this AD. The Director of the Federal Register approved the incorporation by reference of this service bulletin in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You can get a copy from Pratt & Whitney Canada, 1000 Marie-Victorin, Longueuil, Quebec, Canada J4G1A1. You may review copies at the Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-001, on the Internet at http://dms.dot.gov;; or 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.

Related Information

(j) Transport Canada airworthiness directive CF-2003-16, dated June 27, 2003, also addresses the subject of this AD.