E9-3622. Airworthiness Directives; Pratt & Whitney Canada Corp. (P&WC) Models PW305A and PW305B Turbofan Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:

P&WC has determined that the Post-Service Bulletin (SB) PW300-72-24287 High Pressure Compressor (HPC) drum rotor assemblies P/N 30B2478 and 30B2542 on PW 305A and 305B engines with single stage coated labyrinth seals, are susceptible to developing significant cracks in the region of the labyrinth seal.

We are proposing this AD to detect cracks in the HPC drum rotor assembly, which could lead to an uncontained failure of the drum rotor assembly and damage to the airplane.

DATES:

We must receive comments on this proposed AD by March 23, 2009.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
• Fax: [phone].

Examining the AD Docket

You may examine the AD docket 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 AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone [phone]) is the same as the Mail address provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Ian Dargin, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: [e-mail]; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2009-0046; Directorate Identifier 2008-NE-05-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD based on 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 AD. Using the search function of the Web site, anyone can find and read the comments in any of our dockets, including, if provided, 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).

Discussion

Transport Canada, which is the aviation authority for Canada, has issued Canadian Airworthiness Directive CF-2007-25R1, dated February 13, 2008 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:

P&WC has determined that the Post-Service Bulletin (SB) PW300-72-24287 High Pressure Compressor (HPC) drum rotor assemblies P/N 30B2478 and 30B2542 on PW 305A and 305B engines with single stage coated labyrinth seals, are susceptible to developing significant cracks in the region of the labyrinth seal.

P&WC issued SB PW300-72-24462 for initial inspection of affected HPC drum rotor assemblies for cracks. In addition, the PW305 Maintenance Manual (MM) 05-20-00 was revised (Revision No. 26) accordingly, to add requirement for repeat inspection interval. A new P/N 31B6325-01, HPC drum rotor assembly, which is not susceptible to subject cracking, is made available through SB PW300-72-24376, as terminating action for the required repeat inspection.

Recent data (Ref: SIL: PW300-093) indicate that a number of high-time Pre-SB-PW300-72-24376 HPC drum rotor assemblies (P/N 30B2478 and 30B2542), with potential for a hazardous disk failure in consequence of non-compliance with the inspection requirements, are still in-service. This AD is issued to mandate the inspection of the affected P/N 30B2478 and 30B2542 HPC drum rotor assemblies in accordance with PW305-MM-05-20-00 requirements.

You may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

Pratt & Whitney Canada Corp. has issued Service Bulletin PW300-72-24462, dated December 13, 1999. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI.

FAA's Determination and Requirements of This Proposed AD

This product has been approved by the aviation authority of Canada, and is approved for operation in the United States. Pursuant to our bilateral agreement with Canada, they have notified us of the unsafe condition described in the MCAI and service information referenced above. We are issuing this AD because we evaluated all the information provided by Canada and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design.

Costs of Compliance

Based on the service information, we estimate that this proposed AD would affect about 540 products of U.S. registry. We also estimate that it would take about 10 work-hours per product to comply with this proposed AD. The average labor rate is $80 per work-hour. Required parts would cost about $5,000 per product. Based on these figures, we estimate the cost of the proposed AD on U.S. operators to be $3,132,000. Our cost estimate is exclusive of possible warranty coverage.

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.

Regulatory Findings

We determined that this proposed AD would not have federalism implications under Executive Order 13132. 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 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. 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 regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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. The FAA amends § 39.13 by adding the following new AD:

Pratt & Whitney Canada Corp.: Docket No. FAA-2009-0046; Directorate Identifier 2008-NE-05-AD.

Comments Due Date

(a) We must receive comments by March 23, 2009.

Affected Airworthiness Directives (ADs)

(b) None.

Applicability

(c) This AD applies to Pratt & Whitney Canada Corp. (P&WC) Models PW305A and PW305B turbofan engines with high pressure compressor (HPC) drum rotor assemblies, post P&WC Service Bulletin (SB) PW300-72-24287 but without P&WC SB PW300-72-24376, installed. These engines are installed on, but not limited to, Bombardier Learjet M60 and Hawker Beechcraft 1000 series airplanes.

Reason

(d) P&WC has determined that the Post-Service Bulletin (SB) PW300-72-24287 High Pressure Compressor (HPC) drum rotor assemblies P/N 30B2478 and 30B2542 on PW305A and 305B engines with single stage coated labyrinth seals, are susceptible to developing significant cracks in the region of the labyrinth seal.

We are issuing this AD to detect cracks in the HPC drum rotor assembly, which could lead to an uncontained failure of the drum rotor assembly and damage to the airplane.

Actions and Compliance

(e) Unless already done, do the following actions.

(1) Within 500 flight hours after effective date of this directive, borescope-inspect the interiors of affected HPC rotor assemblies for cracks. If a crack is found, remove the engine before next flight for HPC drum rotor replacement. Pratt & Whitney Maintenance Manual, Chapter 72-00-00, contains information about borescope inspection.

Credit for Previous Inspections

(2) Inspection of affected HPC drum rotor assembly per P&WC SB PW300-72-24462 and or SB PW305 MM 05-20-00 inspection requirements prior to the effective date of this directive satisfies the requirements of paragraph (e)(1) of this AD.

(3) Repeat borescope inspection per paragraph (e)(1) of this AD, at intervals not exceeding 1,350 flight cycles. If a crack is found, remove the engine before next flight for HPC rotor drum replacement.

Optional Terminating Action

(4) Replacement of the affected HPC rotor assembly P/N 30B2478 or 30B2542 with Post-SB PW300-72-24376 assembly P/N 31B6325-01 or later superseding P/N, will constitute terminating action for the inspection requirements of the above paragraphs (e)(1) and (e)(2) of the corrective action requirements of this AD.

Other FAA AD Provisions

(f) Alternative Methods of Compliance (AMOCs): The Manager, Engine Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

Related Information

(g) Refer to Canadian Airworthiness Directive CF-2007-25R1, dated February 13, 2008, and P&WC SB PW300-72-24462, dated December 13, 1999, for related information. Contact Pratt & Whitney Canada Corp., 1000 Marie-Victorin, Longueuil, Quebec, Canada J4G 1A1, telephone: [phone], for a copy of this service information.

(h) Contact Ian Dargin, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: [e-mail]; telephone [phone]; fax [phone], for more information about this AD.

Issued in Burlington, Massachusetts, on February 13, 2009.

Peter A. White,

Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service.