
[Federal Register: February 20, 2009 (Volume 74, Number 33)]
[Proposed Rules]               
[Page 7836-7838]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr20fe09-33]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0046; Directorate Identifier 2008-NE-05-AD]
RIN 2120-AA64

 
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).

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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.


[[Page 7837]]


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: (202) 493-2251.

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 (800) 647-5527) 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: 
ian.dargin@faa.gov; telephone (781) 238-7178; fax (781) 238-7199.

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;

[[Page 7838]]

    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.


Sec.  39.13  [Amended]

    2. The FAA amends Sec.  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: (800) 268-8000, 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: ian.dargin@faa.gov; 
telephone (781) 238-7178; fax (781) 238-7199, 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.
 [FR Doc. E9-3622 Filed 2-19-09; 8:45 am]

BILLING CODE 4910-13-P
