
[Federal Register: June 25, 2008 (Volume 73, Number 123)]
[Proposed Rules]               
[Page 35982-35984]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr25jn08-36]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0219; Directorate Identifier 2007-NE-46-AD]
RIN 2120-AA64

 
Airworthiness Directives; Pratt & Whitney Canada PW206A, PW206B, 
PW206B2, PW206C, PW206E, PW207C, PW207D, and PW207E Turboshaft 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 the aviation 
authority of another country to identify and correct an unsafe 
condition on an aviation product. The MCAI describes the unsafe 
condition as:

    PW206 and PW207 compressor turbine (CT) disc bore areas may 
experience impact damage resulting from bending or fracture of the 
CT disc retaining nut. Damage of the CT disc bore area can reduce 
LCF capabilities of the CT disc, resulting in disc fracture.

We are proposing this AD to prevent damage to the CT disc bore area, 
which could result in possible uncontained failure of the engine and 
damage to the helicopter.

DATES: We must receive comments on this proposed AD by July 25, 2008.

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 and 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

[[Page 35983]]

ADDRESSES section. Include ``Docket No. FAA-2007-0219; Directorate 
Identifier 2007-NE-46-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 we 
receive about this proposed AD.

Discussion

    Transport Canada, which is the aviation safety authority for 
Canada, has issued AD CF-2007-24R1, dated December 21, 2007, (referred 
to after this as ``the MCAI'') to correct an unsafe condition for the 
specified products. The MCAI states:

    PW206 and PW207 compressor turbine (CT) disc bore areas may 
experience impact damage resulting from bending or fracture of the 
CT disc retaining nut. Damage of the CT disc bore area can reduce 
LCF capabilities of the CT disc, resulting in disc fracture.

Under high centrifugal loads, the CT disk retaining nut castellations 
might bend outward, then contact and mark the CT disk internal bore. 
Worldwide, a total of 5 events of CT nut damage and associated damage 
to the CT disk bore have been reported. A total of 195 out of 402 
engines in the U.S. fleet have been inspected, with two cases of CT nut 
damage and no findings of disk damage, to date. You may obtain further 
information by examining the MCAI in the AD docket.

Relevant Service Information

    PWC has issued Alert Service Bulletin (ASB) PW200-72-A28280, 
Revision 4, dated August 28, 2007. 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 proposing this AD because we evaluated all 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. 
This proposed AD would require (1) inspecting the CT disc bore area for 
damage and if any damage is noticed, replacing the CT disc before 
further flight; and (2) replacing the existing CT disc retaining nut 
and associated hardware.

Differences Between the Proposed AD and the MCAI

    Although the MCAI allows use of future revisions of PWC ASB PW200-
72-A28280, we require the use of Revision 4 of that ASB.
    Although the MCAI has a March 21, 2008 compliance date, we have a 
December 21, 2008 compliance date, based on a review of the risk 
assessment and the fleet inspection results to date.

Costs of Compliance

    We estimate that this proposed AD would affect 402 engines of U.S. 
registry. We also estimate that it would take 8 work-hours per product 
to comply with this proposed AD. The average labor rate is $80 per 
work-hour. Required parts would cost about $500 per product. We expect 
that 1 disk on the remaining 207 engines will be replaced, at an 
estimated cost of $20,000. Based on these figures, we estimate the cost 
of the proposed AD on U.S. operators to be $478,280. 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.


Sec.  39.13  [Amended]

    2. The FAA amends Sec.  39.13 by adding the following new AD:

Pratt & Whitney Canada: Docket No. FAA-2007-0219; Directorate 
Identifier 2007-NE-46-AD.

Comments Due Date

    (a) We must receive comments by July 25, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This airworthiness directive (AD) applies to Pratt & Whitney 
Canada (PWC) PW206A, PW206B, PW206B2, PW206C, PW206E, PW207C, 
PW207D, and PW207E turboshaft engines.
    (d) These engines are installed on, but not limited to, MD 
Explorer, Agusta S.p.A. A109, A109E, A109S, Bell Helicopter Textron 
Canada Limited 427, Bell 429, and Eurocopter Deutschland GmbH EC135 
P1, and EC135 P2 helicopters.
    (e) For engines that have been converted from one model to 
another, see Effectivity paragraph 1.A. of PWC Alert Service 
Bulletin (ASB) PW200-72-A28280, Revision 4, dated August 28, 2007.

Reason

    (f) Transport Canada AD CF-2007-24R1, dated December 21, 2007, 
states:


[[Page 35984]]


    PW206 and PW207 compressor turbine (CT) disc bore areas may 
experience impact damage resulting from bending or fracture of the 
CT disc retaining nut. Damage of the CT disc bore area can reduce 
LCF capabilities of the CT disc, resulting in disc fracture.

We are issuing this AD to prevent damage to the CT disc bore area, 
which could result in possible uncontained failure of the engine and 
damage to the helicopter.

Actions and Compliance

    (g) Unless already done, do the following actions:
    (1) For engines that have never had a shop visit and have 
accumulated 4,000 CT cycles or more since new; or for engines that 
accumulated 2,700 CT cycles or more since last shop visit, last CT 
disc inspection, or incorporation of PWC SB PW200-72-28287; within 
1,150 hours of engine operating time since April 28, 2006 (original 
issue date of Alert Service Bulletin (ASB) PW200-72-A28280), but not 
later than December 21, 2008, whichever occurs first, accomplish the 
following in accordance with PWC ASB PW200-72-A28280, Revision 4, 
dated August 28, 2007:
    (i) Inspect the CT disc bore area for damage and if any damage 
is noticed, replace the CT disc before further flight.
    (ii) Replace the existing CT disc retaining nut and associated 
hardware.
    (2) For engines that have never had a shop visit and have 
accumulated less than 4,000 CT cycles since new, before the engine 
reaches 4,000 CT cycles or by December 21, 2008, whichever occurs 
later, accomplish the following in accordance with PWC ASB PW200-72-
A28280, Revision 4, dated August 28, 2007:
    (i) Inspect the CT disc bore area for damage and if any damage 
is noticed, replace the CT disc before further flight.
    (ii) Replace the existing CT disc retaining nut and associated 
hardware.
    (3) For engines that have accumulated fewer than 2,700 CT cycles 
since last shop visit, last CT disc inspection, or incorporation of 
PWC SB PW200-72-28287; before the engine reaches 2,700 CT cycles or 
by December 21, 2008, whichever occurs later, accomplish the 
following in accordance with PWC ASB PW200-72-A28280, Revision 4, 
dated August 28, 2007:
    (i) Inspect the CT disc bore area for damage and if any damage 
is noticed, replace the CT disc before further flight.
    (ii) Replace the existing CT disc retaining nut and associated 
hardware.

Previous Credit

    (h) Inspection of the CT disc bore and replacement of the CT 
disc retaining nut using PWC ASB PW200-72-A28280, dated April 28, 
2006, or Revision 1, dated May 11, 2006, or Revision 2, dated 
September 29, 2006, or Revision 3, dated December 11, 2006, before 
the effective date of this AD, meet the requirements of this AD.
    (i) Alternative Methods of Compliance (AMOCs): The Manager, 
Engine Certification Office, FAA, may approve AMOCs for this AD, if 
requested using the procedures found in 14 CFR 39.19.

Related Information

    (j) Refer to Transport Canada Airworthiness Directive 2007-24R1, 
dated December 21, 2007, for related information.
    (k) Contact Ian Dargin, Aerospace Engineer, Engine Certification 
Office, FAA, Engine and Propeller Directorate, 12 New England 
Executive Park; Burlington, MA 01803; e-mail: ian.dargin@faa.gov; 
telephone (781) 238-7178; fax (781) 238-7199.

    Issued in Burlington, Massachusetts, on June 19, 2008.
Diane Cook,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
 [FR Doc. E8-14320 Filed 6-24-08; 8:45 am]

BILLING CODE 4910-13-P
