Airworthiness Directives; Pratt & Whitney (PW) PW4164, PW4168, and PW4168A Turbofan Engines

[Federal Register Volume 73, Number 2 (Thursday, January 3, 2008)]
[Rules and Regulations]
[Pages 394-395]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-25505]


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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] 
Amendment 39-15322; AD 2007-26-20]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney (PW) PW4164, PW4168, 
and PW4168A Turbofan Engines

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

ACTION: Final rule.

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SUMMARY: The FAA is adopting 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 
AD requires removing certain LPT stage 4 disks, listed by serial number 
at the next piece-part exposure or within 7,500 cycles-since-new (CSN). 
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 (LCF), which could result in damage to the 
airplane.

DATES: This AD becomes effective February 7, 2008.

ADDRESSES: The Docket Operations office is located at Docket Management 
Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, 
SE., West Building, Ground Floor, Room W12-140, Washington, DC 20590-
0001.

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: The FAA proposed to amend 14 CFR part 39 
with a proposed AD. The proposed AD applies to PW PW4164, PW4168, and 
PW4168A. We published the proposed AD in the Federal Register on May 
21, 2007 (72 FR 28459). That action proposed to 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.

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 AD, the regulatory evaluation, 
any comments received, and other information. The street address for 
the Docket Operations office (telephone (800) 647-5527) is provided in 
the ADDRESSES section. Comments will be available in the AD docket 
shortly after receipt.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comment received.
    Pratt & Whitney proposes that we not write an AD. Pratt & Whitney 
states that they performed additional testing for low-cycle fatigue 
(LCF). They state the testing shows the disks with the 1-hour heat 
treatment are equivalent to the disks treated with a 4-hour heat 
treatment. We do not agree. The data that PW presents to us doesn't 
conclusively show the 1-hour heat-treat LCF capability is equivalent to 
the 4-hour heat-treat disks. We didn't change the AD.

Conclusion

    We have carefully reviewed the available data, including the 
comment received, and determined that air safety and the public 
interest require adopting the AD as proposed.

Costs of Compliance

    We estimate that this AD will affect 11 engines installed on 
airplanes of U.S. registry. We also estimate that it will take about 
250 work-hours per engine to perform the required action, if not done 
at piece-part exposure, and that the average labor rate is $80 per 
work-hour. Required parts will cost about $186,288

[[Page 395]]

per engine. Based on these figures, we estimate the total cost of the 
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 AD will not have federalism 
implications under Executive Order 13132. This AD will 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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866;
    (2) Is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and
    (3) Will 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 summary of the costs to comply with this AD and 
placed it in the AD Docket. 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.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the Federal Aviation Administration amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

2007-26-20 Pratt & Whitney: Amendment 39-15322. Docket No. FAA-2007-
27230; Directorate Identifier 2007-NE-04-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective February 
7, 2008.

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 
(S/N) listed in the following Table 1, 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
------------------------------------------------------------------------
 
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                      LPT Stage 4 Disk Serial Nos.
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CLDLC01142
CLDLC01143
CLDLC01144
CLDLC01145
CLDLC01146
CLDLC01148
CLDLC01149
CLDLC01150
CLDLC01151
CLDLC01152
CLDLC01181
CLDLC01182
CLDLC01183
CLDLC01185
CLDLC01186
CLDLC01187
------------------------------------------------------------------------

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 an S/N 
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 an S/N 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) 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, for more information about this AD.

Material Incorporated by Reference

    (k) None.

    Issued in Burlington, Massachusetts, on December 20, 2007.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
 [FR Doc. E7-25505 Filed 1-2-08; 8:45 am]
BILLING CODE 4910-13-P

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