[Federal Register: May 21, 2007 (Volume 72, Number 97)]
[Proposed Rules]
[Page 28459-28461]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr21my07-6]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2007-27230; Directorate Identifier 2007-NE-04-AD]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney (PW) PW4164, PW4168,
and PW4168A 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 PW4164, PW4168, and PW4168A turbofan engines with certain low
pressure turbine (LPT) stage 4 disks, part number (P/N) 51N404,
installed. This proposed AD would require removing certain LPT stage 4
disks, listed by serial number at the next piece-part exposure or
within 7,500 cycles-since-new (CSN), whichever occurs first. This
proposed AD results from a report of improperly manufactured LPT stage
4 disks. We are proposing this AD to prevent an uncontained engine
failure due to low-cycle fatigue (LCF), which could result in damage to
the airplane.
DATES: We must receive any comments on this proposed AD by July 20,
2007.
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 may examine the comments on this proposed AD in the AD docket
on the Internet at http://dms.dot.gov.
FOR FURTHER INFORMATION CONTACT: V. Rose Len, Aerospace Engineer,
Engine Certification Office, FAA, Engine & Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803; telephone (781) 238-
7772; 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-2007-27230;
Directorate Identifier 2007-NE-04-AD'' in the subject line of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy
[[Page 28460]]
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 Docket Management
Facility 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 September 29, 2006, we received a report of 16 LPT stage 4
disks, P/N 51N404, manufactured with an improper material process. The
disks were not properly heat treated during the manufacturing process.
The manufacturer solution-heat treated the disks for one hour instead
of the four hours required. We believe this manufacturing discrepancy
will result in reduced LCF properties for the disks. Operating the
affected disks to the certified life limit could result in uncontained
failure of the disk due to LCF. Although we have received no reports of
disk separations, this condition, if not corrected, could result in the
disk separating from the engine due to LCF, which could result in
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
removing certain LPT stage 4 disks, P/N 51N404, listed by serial number
in the proposed AD, at the next piece-part exposure, or within 7,500
CSN, whichever occurs first.
Costs of Compliance
We estimate that this proposed AD would affect 11 engines installed
on airplanes of U.S. registry. We also estimate that it would take
about 250 work-hours per engine to perform the proposed action, if not
done at piece-part exposure, and that the average labor rate is $80 per
work-hour. Required parts would cost about $186,288 per engine. Based
on these figures, we estimate the total cost of the proposed AD to U.S.
operators to be $2,269,168.
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-2007-27230; Directorate Identifier
2007-NE-04-AD.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive
comments on this airworthiness directive (AD) action by July 20,
2007.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Pratt & Whitney PW4164, PW4168, and
PW4168A turbofan engines with certain low pressure turbine (LPT)
stage 4 disks, part number (P/N) 51N404, that have a serial number
listed in the following Table 1 of this AD installed. These engines
are installed on, but not limited to, Airbus A330-200 and A330-300
series airplanes.
Table 1.--Affected LPT Stage 4 Disks by Serial Number
LPT stage 4 disk serial numbers
CLDLC01142
CLDLC01143
CLDLC01144
CLDLC01145
CLDLC01146
CLDLC01148
CLDLC01149
CLDLC01150
CLDLC01151
CLDLC01152
CLDLC01181
CLDLC01182
CLDLC01183
CLDLC01185
CLDLC01186
CLDLC01187
[[Page 28461]]
Unsafe Condition
(d) This AD results from a report of improperly manufactured LPT
stage 4 disks. We are issuing this AD to prevent an uncontained
engine failure due to low-cycle fatigue, which could result in
damage to the airplane.
Compliance
(e) You are responsible for having the actions required by this
AD performed at the next piece-part exposure after the effective
date of this AD or within 7,500 cycles-since-new, unless the actions
have already been done.
Removing the LPT Stage 4 Disk
(f) Remove from service any LPT stage 4 disk that has a serial
number listed in Table 1 of this AD.
Prohibition Against Installing an Affected Disk
(g) After the effective date of this AD, do not install any
disk, P/N 51N404, that has a serial number listed in Table 1 of this
AD or any disk removed as specified in paragraph (f) of this AD
except as allowed by paragraph (h) of this AD.
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.
Special Flight Permits
(i) Under 14 CFR part 39.23, we are prohibiting the special
flight permits for this AD.
Related Information
(j) None.
Issued in Burlington, Massachusetts, on May 11, 2007.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. E7-9697 Filed 5-18-07; 8:45 am]
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