[Federal Register Volume 71, Number 149 (Thursday, August 3, 2006)]
[Proposed Rules]
[Pages 43997-43998]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-12539]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24452; Directorate Identifier 2006-NE-11-AD]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney PW2000 Series Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for Pratt & Whitney PW2000 series turbofan engines. This proposed AD 
would require a onetime focused visual and fluorescent penetrant 
inspection (FPI) of 21 suspect PW2000 8th stage high pressure 
compressor (HPC) drum rotor disk assemblies. This proposed AD results 
from a PW2037 8th stage HPC drum rotor disk assembly failure event 
caused by tooling damage that occurred during disk assembly 
manufacture. We are proposing this AD to prevent 8th stage HPC drum 
rotor disk assembly failure that could result in an uncontained engine 
failure and damage to the airplane.

DATES: We must receive any comments on this proposed AD by October 2, 
2006.

ADDRESSES: Use one of the following addresses to comment on this 
proposed 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 20590-0001.
     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 proposed AD 
from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone 
(860) 565-8770; fax (860) 565-4503.
    You may examine the comments on this proposed AD in the AD docket 
on the Internet at http://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT: Mark Riley, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; telephone (781) 238-7758; 
fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send us any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2006-24452; 
Directorate Identifier 2006-NE-11-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed 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 proposed AD. Using the search function of the 
DOT 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.

Examining the AD Docket

    You may examine the docket that contains the proposal, any comments 
received and, any final disposition in person at the DOT Docket Office 
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 Docket Management Facility receives 
them.

Discussion

    On March 10, 2005, a PW2037 uncontained 8th stage HPC drum rotor 
disk assembly failure event occurred. The event occurred during takeoff 
and resulted in an inflight engine shutdown. A subsequent investigation 
confirmed the primary cause of the failure to be tooling damage (an 
improperly blended toolmark) that occurred during disk assembly 
manufacture. Tooling damage resulted in excessive stresses in the disk 
web section, which led to the disk assembly failure and uncontained 
engine event. Further investigation confirmed that there are 21 suspect 
PW2000 8th stage HPC drum rotor disk assemblies currently in service 
worldwide that have the potential for similar machining damage 
occurring during disk assembly manufacture. This machining damage could 
result in failure of the 8th stage HPC drum rotor disk assembly and 
result in an uncontained engine failure and damage to the airplane.

Relevant Service Information

    We have reviewed and approved the technical contents of Pratt & 
Whitney

[[Page 43998]]

Alert Service Bulletin PW2000 A72-706, dated February 17, 2006, that 
describes procedures for a onetime focused visual and FPI of suspect 
PW2000 8th stage HPC drum rotor disk assemblies that may have been 
damaged during original manufacture.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other products 
of this same type design. We are proposing this AD, which would require 
a onetime focused visual and FPI of 21 suspect PW2000 8th stage HPC 
drum rotor disk assemblies. The proposed AD would require you to use 
the service information described previously to perform these actions.

Costs of Compliance

    We estimate that this proposed AD would affect 15 engines installed 
on airplanes of U.S. registry. We also estimate that it would take 
about 70 workhours per engine to perform the proposed actions, and that 
the average labor rate is $80 per workhour. We do not expect that parts 
will be required. Based on these figures, we estimate the total cost of 
the proposed AD to U.S. operators to be $84,000 for the inspection.

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 have 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 that the 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. Would 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. See the ADDRESSES section for a location 
to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Under the authority delegated to me by the Administrator, the 
Federal Aviation Administration 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 
airworthiness directive:

Pratt & Whitney: Docket No. FAA-2006-24452; Directorate Identifier 
2006-NE-11-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by October 2, 
2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Pratt & Whitney PW2037, PW2040, PW2037M 
turbofan engines. These engines are installed on, but not limited to 
Boeing 757 airplanes.

Unsafe Condition

    (d) This AD results from a Pratt & Whitney PW2037 8th stage 
high-pressure compressor (HPC) drum rotor disk assembly failure 
event caused by tooling damage that occurred during disk assembly 
manufacture. We are issuing this AD to prevent 8th stage HPC drum 
rotor disk assembly failure that could result in an uncontained 
engine failure and damage to the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed at the next shop visit, not to exceed an additional 
6000 engine cycles, after the effective date of this AD, when the 
8th stage HPC drum rotor disk assembly is exposed and removed from 
the HPC module, unless the actions have already been done.

Inspect the 8th Stage Drum Rotor Disk

    (f) Using the Accomplishment Instructions of Pratt & Whitney 
Alert Service Bulletin PW2000 A72-706, dated February 17, 2006, do a 
onetime focused visual and fluorescent penetrant inspection (FPI) of 
suspect 8th stage HPC drum rotor disk assemblies that may have been 
damaged during manufacture. Any 8th stage disk damage that exceeds 
the serviceable limits specified in Pratt & Whitney PW2000 Engine 
Manual, Part Number 1A6231, Chapter/Section 72-35-03, Inspection/
Check-01/-04, can not be returned to service. Table 1 of the 
Accomplishment Instructions lists the part numbers and serial 
numbers of the HPC drum rotor disk assemblies requiring inspection.
    (g) After the effective date of this AD, do not install any 
uninspected 8th stage drum rotor disk assemblies listed in Table 1 
of the Accomplishment Instructions of Pratt & Whitney Alert Service 
Bulletin PW2000 A72-706, dated February 17, 2006, in any engine.

Alternative Methods of Compliance

    (h) 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.

    Issued in Burlington, Massachusetts, on July 27, 2006.
Francis A. Favara,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. E6-12539 Filed 8-2-06; 8:45 am]
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