[Federal Register: October 10, 2007 (Volume 72, Number 195)]
[Proposed Rules]
[Page 57502-57503]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr10oc07-15]
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Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2007-29110; Directorate Identifier 2007-NE-35-AD]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney PW4090 and PW4090-3
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 (PW) PW4090 and PW4090-3 turbofan engines with
front turbine hub, part number (P/N) 53L601, installed. This proposed
AD would reduce the published life limit of those front turbine hubs
from 12,000 cycles-since-new (CSN) to 9,370 CSN. This proposed AD would
also remove from service those front turbine hubs using a drawdown
schedule. This proposed AD results from PW updating the low-cycle-
fatigue (LCF) life analysis for front turbine hubs, P/N 53L601. We are
proposing this AD to prevent an uncontained failure of the front
turbine hub, resulting in an in-flight engine shutdown and possible
damage to the airplane.
DATES: We must receive any comments on this proposed AD by December 10,
2007.
ADDRESSES: Use one of the following addresses to comment on this
proposed AD.
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.
FOR FURTHER INFORMATION CONTACT: Mark Riley, Aerospace Engineer, Engine
Certification Office, FAA, Engine & Propeller Directorate, 12 New
England Executive Park, Burlington, MA 01803; e-mail:
mark.riley@faa.gov, 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-2007-29110;
Directorate Identifier 2007-NE-35-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 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
PW Engineering updated their life analysis for the front turbine
hub, P/N 53L601, to incorporate new temperature data in the hub aft
cavity area. The revised cavity temperatures cause higher than
anticipated stress levels in the anti-rotation slots of the front
turbine hub. This results in a reduced published LCF life limit from
12,000 CSN to 9,370 CSN. This condition, if not corrected, could result
in uncontained engine failure resulting in an in-flight engine shutdown
and possible 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:
Reduce the published life limit of front turbine hub, P/N
53L601, from 12,000 CSN to 9,370 CSN; and
Remove from service those front turbine hubs using a
drawdown schedule.
Costs of Compliance
We estimate that this proposed AD would affect 94 engines installed
on airplanes of U.S. registry. We also estimate that it would take
about 101 work-hours per engine to perform the proposed actions, and
that the average labor rate is $80 per work-hour. The prorated cost due
to a life reduction from 12,000 CSN to 9,370 CSN for the front turbine
hub is about $66,460 per engine. Based on these figures, we estimate
the cost of the proposed AD on U.S. operators to be $6,247,240.
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
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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-2007-29110; Directorate Identifier
2007-NE-35-AD.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive
comments on this airworthiness directive (AD) action by December 10,
2007.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Pratt & Whitney (PW) PW4090 and PW4090-3
turbofan engines with front turbine hub part number (P/N) 53L601,
installed. These engines are installed on, but not limited to,
Boeing 777-200 series and 777-300 series airplanes.
Unsafe Condition
(d) This AD results from PW updating the low-cycle-fatigue (LCF)
life analysis for front turbine hubs, P/N 53L601. We are proposing
this AD to prevent an uncontained failure of the front turbine hub,
resulting in an in-flight engine shutdown and possible damage to the
airplane.
Compliance
(e) You are responsible for having the actions required by this
AD performed within the compliance times specified unless the
actions have already been done.
(f) Remove front turbine hubs, P/N 53L601, from service and
install a serviceable front turbine hub, as follows:
(1) For front turbine hubs that have accumulated fewer than
3,370 cycles-since-new (CSN) on the effective date of this AD,
remove from service before the hub accumulates 9,370 CSN.
(2) For front turbine hubs that have accumulated 3,370 or more
CSN, but fewer than 9,370 CSN on the effective date of this AD, do
the following:
(i) For engines that have an engine shop visit (ESV) before the
front turbine hub accumulates 9,370 CSN, remove the front turbine
hub from service before the hub accumulates 9,370 CSN.
(ii) For engines that do not have an ESV before the front
turbine hub accumulates 9,370 CSN, remove the front turbine hub from
service at the next ESV, or before the hub accumulates an additional
6,000 cycles-since-last high pressure turbine overhaul, whichever
occurs first, but not to exceed 12,000 CSN.
(3) For front turbine hubs that have accumulated 9,370 or more
CSN on the effective date of this AD, remove the front turbine hub
from service at the next ESV, or before the hub accumulates 12,000
CSN, whichever occurs first.
(g) This AD establishes a new reduced published life limit for
the PW4090 turbine front hub, P/N 53L601, of 9,370 CSN, which is
published in Chapter 05, Time Limits Section 05-10-01, of the PW4000
Series Engine Shop Manual, P/N 51A751. The following conditions also
apply:
(1) Except as provided in paragraphs (f)(2)(ii) and (f)(3) of
this AD, no alternative retirement lives may be approved for the
PW4090 front turbine hub, P/N 53L601.
(2) After the effective date of this AD, PW4090 front turbine
hub, P/N 53L601, may not be installed or reinstalled on an engine if
the hub has accumulated more than 9,370 CSN.
(h) For the purposes of this AD, an ``engine shop visit'' is:
(1) The induction of an engine into the shop for maintenance
involving the separation of any major mating engine flange, except
that for the separation of engine flanges solely for the purposes of
transportation without subsequent engine maintenance does not
constitute an engine shop visit; or
(2) The removal of a disk or spool.
Alternative Methods of Compliance
(i) 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
(j) Information on an approved front turbine hub rework
procedure for increased life is available from the manufacturer. See
Pratt & Whitney Service Bulletin PW4G-112-72-290, dated July 2,
2007. The reworked front turbine hub, P/N 53L601-001, is not
affected by this AD.
(k) Contact Mark Riley, Aerospace Engineer, Engine Certification
Office, FAA, Engine & Propeller Directorate, 12 New England
Executive Park, Burlington, MA 01803; e-mail: mark.riley@faa.gov,
telephone (781) 238-7758; fax (781) 238-7199, for more information
about this AD.
Issued in Burlington, Massachusetts, on October 2, 2007.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. E7-19927 Filed 10-9-07; 8:45 am]
BILLING CODE 4910-13-P