[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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