[Federal Register Volume 77, Number 139 (Thursday, July 19, 2012)]
[Rules and Regulations]
[Pages 42424-42425]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-17001]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-1095; Directorate Identifier 2009-NE-40-AD; 
Amendment 39-17104; AD 2012-13-02]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are superseding an existing airworthiness directive (AD) 
for all Pratt & Whitney Division PW4074 and PW4077 turbofan engines. 
That AD currently requires removing the 15th stage high-pressure 
compressor (HPC) disk within 12,000 cycles since new (CSN) or using a 
drawdown removal plan for disks that exceed 12,000 CSN. This new AD 
requires the same actions and clarifies that 15th stage HPC disks that 
have accumulated more than 9,865 CSN require a borescope inspection 
(BSI) or eddy current inspection (ECI) of the disk outer rim front rail 
for cracks prior to accumulating 12,000 CSN. This AD was prompted by a 
request from an operator that we clarify our inspection schedule for 
15th stage HPC disks that have accumulated more than 9,865, but less 
than 12,000 CSN, on the effective date of the AD. We are issuing this 
AD to prevent cracks from propagating into the disk bolt holes, which 
could result in a failure of the 15th stage HPC disk, uncontained 
engine failure, and damage to the airplane.

DATES: This AD is effective August 23, 2012.
    The Director of the Federal Register approved the incorporation by 
reference of a certain other publication listed in this AD as of 
September 8, 2011 (76 FR 47056, August 4, 2011).

ADDRESSES: For service information identified in this AD, contact Pratt 
& Whitney, 400 Main St., East Hartford, CT 06108; phone: 860-565-7700; 
fax: 860-565-1605. You may review copies of the referenced service 
information at the FAA, Engine & Propeller Directorate, 16 New England 
Executive Park, Burlington, MA. For information on the availability of 
this material at the FAA, call 781-238-7125.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility 
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 address for the 
Docket Office (phone: 800-647-5527) is Document Management Facility, 
U.S. Department of Transportation, Docket Operations, M-30, West 
Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., 
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Ian Dargin, Aerospace Engineer, Engine 
Certification Office, FAA, 12 New England Executive Park, Burlington, 
MA 01803; phone: 781-238-7178; fax: 781-238-7199; email: 
[email protected].

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to supersede AD 2011-14-07, Amendment 39-16742 (76 FR 47056, 
August 4, 2011). That AD applies to the specified products. The NPRM 
published in the Federal Register on February 24, 2012 (77 FR 11017). 
That NPRM proposed to continue to require removing the 15th stage HPC 
disk within 12,000 CSN or using a drawdown removal plan for disks that 
exceed 12,000 CSN. That NPRM also proposed to clarify our inspection 
schedule for 15th stage HPC disks that have accumulated more than 
9,865, but less than 12,000 CSN, on the effective date of the AD.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We have considered the comments received. United Airlines and 
The Boeing Company support the NPRM.

Conclusion

    We reviewed the relevant data, considered the comments 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 44 engines installed on 
airplanes of U.S. registry. Prorated parts life will cost about $66,000 
per 15th stage HPC disk. Based on these figures, we estimate the total 
cost of the AD to U.S. operators to be $2,904,000. The new requirements 
of this AD add no additional economic burden.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I,

[[Page 42425]]

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),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA 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 removing airworthiness directive (AD) 
2011-14-07, Amendment 39-16742 (76 FR 47056, August 4, 2011), and 
adding the following new AD:

2012-13-02 Pratt & Whitney Division: Amendment 39-17104; Docket No. 
FAA-2010-1095; Directorate Identifier 2009-NE-40-AD.

(a) Effective Date

    This AD is effective August 23, 2012.

(b) Affected ADs

    This AD supersedes AD 2011-14-07, Amendment 39-16742 (76 FR 
47056, August 4, 2011).

(c) Applicability

    This AD applies to Pratt & Whitney Division PW4074 and PW4077 
turbofan engines with 15th stage high-pressure compressor (HPC) 
disks, part number (P/N) 55H615, installed.

(d) Unsafe Condition

    This AD results from multiple shop findings of cracked 15th 
stage HPC disks. We are issuing this AD to prevent cracks from 
propagating into the disk bolt holes, which could result in a 
failure of the 15th stage HPC disk, uncontained engine failure, and 
damage to the airplane.

(e) Compliance

    Comply with this AD within the compliance times specified, 
unless already done. To perform the inspections, use paragraph 1.A. 
or 1.B. of the Accomplishment Instructions ``For Engines Installed 
on the Aircraft'' or 1.A. or 1.B. of the Accomplishment Instructions 
``For Engines Removed from the Aircraft,'' of Pratt & Whitney 
Service Bulletin PW4G-112-72-309, Revision 1, dated July 1, 2010.
    (1) For 15th stage HPC disks that have 9,865 or fewer cycles 
since new (CSN) on the effective date of this AD, remove the disk 
from service before accumulating 12,000 CSN.
    (2) For 15th stage HPC disks that have accumulated more than 
9,865 CSN on the effective date of this AD, do one of the following:
    (i) Remove the disk from service at the next piece-part 
exposure, not to exceed 2,135 cycles-in-service (CIS) after the 
effective date of this AD.
    (ii) Perform a borescope inspection (BSI) or eddy current 
inspection (ECI) of the front rail of the disk outer rim according 
to the following schedule:
    (A) Within 2,400 cycles-since-last fluorescent penetrant 
inspection or ECI, or
    (B) Within 1,200 cycles-since-last BSI, or
    (C) Before accumulating 12,000 CSN, or
    (D) Within 55 CIS after the effective date of this AD, whichever 
occurs latest.
    (3) If the BSI from paragraph (e)(2)(ii) of this AD indicates 
the presence of a crack in the disk outer rim front rail, but you 
cannot visually confirm a crack, perform an ECI within 5 CIS after 
the BSI.
    (4) If you confirm a crack in the front rail of the disk outer 
rim using any inspection method, remove the disk from service before 
further flight.

(f) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, may approve AMOCs for 
this AD. Use the procedures found in 14 CFR 39.19 to make your 
request.

(g) Related Information

    For more information about this AD, contact Ian Dargin, 
Aerospace Engineer, Engine Certification Office, FAA, 12 New England 
Executive Park, Burlington, MA 01803; phone: 781-238-7178; fax: 781-
238-7199; email: [email protected].

(h) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Pratt & Whitney Service Bulletin PW4G-112-72-309, Revision 
1, dated July 1, 2010, approved for IBR September 8, 2011.
    (ii) Reserved.
    (3) For Pratt & Whitney service information identified in this 
AD, contact Pratt & Whitney, 400 Main St., East Hartford, CT 06108; 
phone: 860-565-7700; fax: 860-565-1605.
    (4) You may review copies of the referenced service information 
at the FAA, Engine & Propeller Directorate, 16 New England Executive 
Park, Burlington, MA. For information on the availability of this 
material at the FAA, call 781-238-7125.
    (5) You may also review copies of the service information that 
is incorporated by reference at the National Archives and Records 
Administration (NARA). For information on the availability of this 
material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr_locations.html.

    Issued in Burlington, Massachusetts, on June 19, 2012.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-17001 Filed 7-18-12; 8:45 am]
BILLING CODE 4910-13-P