[Federal Register Volume 73, Number 221 (Friday, November 14, 2008)]
[Proposed Rules]
[Pages 67427-67429]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-26909]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2008-1131; Directorate Identifier 2008-NE-37-AD]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney (PW) Models PW2037,
PW2037(M), and PW2040 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 PW models PW2037, PW2037(M), and PW2040 turbofan engines. This
proposed AD would require inspecting all high-pressure turbine (HPT)
2nd stage hubs at the next HPT overhaul after the effective date of the
proposed AD. The inspections of the hubs include fluorescent penetrant
inspection (FPI) for cracks and an optical comparator inspection (OCI)
of the blade retention slots to confirm the hubs are within dimensional
tolerances before returning them to service. This proposed AD results
from an uncontained release of HPT 2nd stage blades and blade retention
lugs. We are proposing this AD to detect cracks and remove
nonconforming HPT 2nd stage hubs, which could result in an uncontained
release of turbine blades and blade retention lugs, and damage to the
airplane.
DATES: We must receive any comments on this proposed AD by January 13,
2009.
ADDRESSES: Use one of the following addresses to comment on this
proposed AD.
Federal Rulemaking 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.
Contact Pratt & Whitney, 400 Main Street, East Hartford, CT 06108
for the service information identified in this AD.
FOR FURTHER INFORMATION CONTACT: Mark Riley, Aerospace Engineer, Engine
Certification Office, FAA, Engine and Propeller Directorate, 12 New
England Executive Park, Burlington, MA 01803; e-mail:
[email protected]; 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-2008-1131; Directorate
Identifier 2008-NE-37-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://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).
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
[[Page 67428]]
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.
Discussion
On August 6, 2008, a PW2037 turbofan engine experienced an
uncontained failure of multiple HPT 2nd stage blades. Although the root
cause is still under investigation, we have determined that cracks in
the blade retention lugs of the HPT 2nd stage hub resulted in fracture
of multiple lugs, and release of 2nd stage blades. Optical comparator
inspections (OCIs) performed on the blade retention slots of the HPT
2nd stage hub confirmed the slots were out of dimensional tolerances.
HPT 2nd stage hubs with blade retention slots that are out of tolerance
can cause cracks and fracture of multiple blade retention lugs and
release of 2nd stage blades from the hub. This condition, if not
corrected, could result in an uncontained release of turbine blades and
blade retention lugs, and damage to the airplane.
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
performing an FPI of the hub for cracks and an OCI of the blade
retention slots on the forward and aft sides of the HPT 2nd stage hub
for conformance to dimensional tolerances at the next HPT overhaul
after the effective date of this AD.
Interim Action
These actions are interim actions and we are requiring reporting
inspection data, including negative findings, to determine if we need
to take further rulemaking actions in the future.
Costs of Compliance
We estimate that this proposed AD would affect 762 engines
installed on airplanes of U.S. registry. We also estimate that it would
take about 6 work-hours per engine to perform the proposed actions, and
that the average labor rate is $80 per work-hour. No parts are
required. Based on these figures, we estimate the total cost of the
proposed AD to U.S. operators to be $365,760.
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 AD:
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. You may get a copy of this summary at the
address listed under ADDRESSES.
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-2008-1131; Directorate Identifier
2008-NE-37-AD.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive
comments on this airworthiness directive (AD) action by January 13,
2009.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Pratt & Whitney models PW2037, PW2037(M),
and PW2040 turbofan engines. These engines are installed on, but not
limited to, Boeing 757-200 and 757-300 airplanes.
Unsafe Condition
(d) This AD results from an uncontained release of high-pressure
turbine (HPT) 2nd stage blades and blade retention lugs. We are
issuing this AD to detect cracks and remove nonconforming HPT 2nd
stage hubs, which could result in an uncontained release of turbine
blades and blade retention lugs, and damage to the airplane.
Compliance
(e) You are responsible for having the actions required by this
AD performed at the next HPT overhaul, unless the actions have
already been done.
Performing Inspections on HPT 2nd Stage Hubs
(f) Perform a fluorescent penetrant inspection (FPI) of the hub
for cracks. Pratt & Whitney Engine Manual part number 1A6231
(Chapter 72-52-00, Inspection/Check-02, (Subtask 72-52-16-230-007))
contains information on performing the FPI.
(g) Remove from service any cracked hubs.
(h) Any HPT 2nd stage hubs inspected as specified in paragraphs
(f) of this AD, must pass an optical comparator inspection before
the hubs are eligible for return to service. Pratt & Whitney Alert
Service Bulletin, PW2000 A72-734, contains information about the
inspection.
Reporting Requirements
(i) For 6 months from the effective date of the AD, and within
72 hours of completing the inspections required by this AD, report
the following to the Engine Certification Office, ATTN: Mark Riley,
Engine & Propeller Directorate, 12 New England Executive Park,
Burlington, MA 01803:
(1) Inspection Date.
(2) Disk part number and serial number.
(3) Hours since new.
(4) Cycles since new.
(5) Hours since overhaul.
(6) Cycles since overhaul.
(7) Fluorescent penetrant inspection findings.
(8) Optical comparator inspection findings.
(j) Under the provisions of the Paperwork Reduction Act, the
Office of Management and
[[Page 67429]]
Budget (OMB) have approved the information collection requirements
and has assigned OMB Control Number 2120-0056.
Definitions
(k) This AD defines an HPT overhaul as when the HPT is at its
piece-part level.
Alternative Methods of Compliance
(l) 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.
Related Information
(m) Contact Mark Riley, Aerospace Engineer, Engine Certification
Office, FAA, Engine and Propeller Directorate, 12 New England
Executive Park, Burlington, MA 01803; e-mail: [email protected];
telephone (781) 238-7758, fax (781) 238-7199, for more information
about this AD.
(n) Pratt & Whitney Alert Service Bulletin, PW2000 A72-734,
contains information about the optical comparator inspection.
Issued in Burlington, Massachusetts, on November 6, 2008.
Francis A. Favara,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. E8-26909 Filed 11-13-08; 8:45 am]
BILLING CODE 4910-13-P