Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan Engines

[Federal Register Volume 75, Number 242 (Friday, December 17, 2010)]
[Rules and Regulations]
[Pages 78881-78883]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-31723]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0596; Directorate Identifier 2010-NE-22-AD; 
Amendment 39-16533; AD 2010-24-14]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Pratt & Whitney PW4000 series turbofan engines. This AD 
requires initial and repetitive borescope inspections (BSI) or 
fluorescent penetrant inspections (FPI) for cracks in the anti-vortex 
tube (AVT) shelf slots on the 10th stage disk of the high-pressure 
compressor (HPC) drum rotor disk assembly. This AD results from 47 
reports received since 2007 of HPC 10th stage disks found cracked in 
the AVT shelf slots during shop visit inspections. We are issuing this 
AD to prevent failure of the HPC 10th stage disk, uncontained engine 
failure, and damage to the airplane.

DATES: This AD becomes effective January 21, 2011. The Director of the 
Federal Register approved the incorporation by reference of certain 
publications listed in the regulations as of January 21, 2011.

ADDRESSES: You can get the service information identified in this AD 
from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone 
(860) 565-8770; fax (860) 565-4503.
    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: James Gray, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; e-mail: 
[email protected]; telephone (781) 238-7742; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39 
with a proposed AD. The proposed AD applies to certain Pratt & Whitney 
PW4000 series turbofan engines. We published the proposed AD in the 
Federal Register on July 14, 2010 (75 FR 40757). That action proposed 
to require initial and repetitive BSI or FPI for cracks in the AVT 
shelf slots on the 10th stage disk of the HPC drum rotor disk assembly.

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 comments received.

Request for Airplane Model Changes in the Applicability

    One commenter, The Boeing Company, requests that we change the list 
of airplane models in the applicability paragraph. The commenter 
requests that we add the 747-400 and -400F airplane models, and remove 
the 747-200 airplane model. These changes will make the list accurate.
    We agree. We changed the AD applicability to reflect these changes.

Request To Include Engine Removal Disassembly Labor Costs

    One commenter, Japan Airlines, requests that we change the costs of 
compliance estimate to include engine removal and disassembly labor 
costs. The commenter states that their domestic routes can go 7,000 
cycles-in-service or more between engine overhauls. Since the 
inspection compliance interval in the proposed AD is within every 7,200 
cycles-in-service, some of their engines could be removed and 
disassembled before they would normally be scheduled.
    We do not agree. The inspection compliance interval of within every 
7,200 cycles-in-service captures when most of the fleet will remove the 
low-pressure turbine shaft, or overhaul the HPC. Most operators will 
incur no additional costs. We did not change the AD.

Request To Add Service Bulletins as Terminating Action

    Two commenters, Martinair Holland and Delta Airlines, Inc., request 
that we add Pratt & Whitney Service Bulletin (SB) No. PW4ENG 72-801 to 
the AD as terminating action for the repeat inspection. The commenters 
state that Pratt & Whitney issued that SB, as well as SB No. PW4G-100-
72-225, to introduce a redesigned HPC 9th stage stator that will 
correct the cracking problem.
    We agree. We modified the AD to include optional terminating action 
for the repetitive inspections.

Reference the Latest Service Bulletin

    Since we issued the proposed AD, Pratt & Whitney has issued 
Revision 1 of Pratt & Whitney SB No. PW4ENG 72-799. We updated the AD 
to reference Revision 1 of this SB.

[[Page 78882]]

Conclusion

    We have carefully reviewed the available data, including the 
comments received, and determined that air safety and the public 
interest require adopting the AD with the changes described previously. 
We have determined that these changes will neither increase the 
economic burden on any operator nor increase the scope of the AD.

Interim Actions

    These actions are interim actions and we may take further 
rulemaking actions in the future.

Costs of Compliance

    We estimate that this AD will affect 869 engines installed on 
airplanes of U.S. registry. We also estimate that it will take about 
one work-hour per engine to perform an inspection, and that the average 
labor rate is $85 per work-hour. Required parts will cost about 
$303,010 per HPC drum rotor disk assembly. About 61 HPC drum rotor disk 
assemblies will need replacement due to cracks. Based on these figures, 
we estimate the cost of the AD on U.S. operators to be $18,557,475.

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, Incorporation by 
reference, 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:

2010-24-14 Pratt & Whitney: Amendment 39-16533. Docket No. FAA-2010-
0596; Directorate Identifier 2010-NE-22-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective January 
21, 2011.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to the following Pratt & Whitney turbofan 
engines with a ring case configuration rear high-pressure compressor 
(HPC) installed, that includes a 9th stage compressor stator segment 
assembly with 24 slots. These engines are installed on, but not 
limited to, Boeing 747-400/-400F, 767-200/-300, and MD-11 airplanes, 
and Airbus A300-600, A310-300, A330-300, and A330-200 airplanes.

PW4000-94'' Engines

    (1) PW4000-94'' series engine models PW4050, PW4052, PW4056, 
PW4060, PW4060A, PW4060C, PW4062, PW4062A, PW4152, PW4156, PW4156A, 
PW4158, PW4160, PW4460, PW4462, and PW4650, including all models 
with a dash number suffix.

PW4000-100'' Engines

    (2) PW4000-100'' series engine models PW4168A-1D and PW4170 with 
serial numbers P735001 through P735039; and
    (3) All engines converted to PW4164-1D, PW4168-1D, PW4168A-1D, 
or PW4170 model engines.

Unsafe Condition

    (d) This AD results from 47 reports received since 2007 of HPC 
10th stage disks found cracked in the anti-vortex tube (AVT) shelf 
slots during shop visit inspections. We are issuing this AD to 
prevent failure of the HPC 10th stage disk, uncontained engine 
failure, and 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.

Initial Inspection of the AVT Shelf Slots

    (f) For engines listed in paragraphs (c)(1) and (c)(3) of this 
AD, do the following:
    (1) Remove the low-pressure turbine (LPT) shaft and borescope-
inspect (BSI) for cracks in the AVT shelf slots on the 10th stage 
disk of the HPC drum rotor disk assembly; or
    (2) Remove the HPC drum rotor disk assembly and fluorescent-
penetrant inspect (FPI) for cracks in the AVT shelf slots on the 
10th stage disk of the HPC drum rotor disk assembly.
    (3) Perform the inspection:
    (i) Within 7,200 cycles-in-service (CIS) since incorporation of 
any of the following Pratt & Whitney Service Bulletins: (SB) No. 
PW4ENG 72-755, SB No. PW4ENG 72-756, SB No. PW4ENG 72-757, SB No. 
PW4ENG 72-759, or SB No. PW4G-100-72-220; or
    (ii) Within 1,000 CIS after the effective date of this AD, 
whichever occurs later.
    (4) If a crack is found, remove the HPC drum rotor disk assembly 
from service.
    (g) For engines listed in paragraph (c)(2) of this AD, do the 
following:
    (1) Remove the LPT shaft and BSI for cracks in the AVT shelf 
slots on the 10th stage disk of the HPC drum rotor disk assembly; or
    (2) Remove the HPC drum rotor disk assembly and FPI for cracks 
in the AVT shelf slots on the 10th stage disk of the HPC drum rotor 
disk assembly.
    (3) Perform the inspection:
    (i) Within 7,200 cycles-since-new; or
    (ii) Within 1,000 CIS after the effective date of this AD, 
whichever occurs later.
    (4) If a crack is found, remove the HPC drum rotor disk assembly 
from service.

Repetitive Inspections of the AVT Shelf Slots

    (h) Thereafter, perform a BSI or FPI for cracks in the AVT shelf 
slots on the 10th stage HPC disk of the HPC drum rotor disk assembly 
within every 7,200 cycles-since-last-inspection.
    (i) If a crack is found, remove the HPC drum rotor disk assembly 
from service.

Relevant Service Bulletins

    (j) Use paragraphs 3.A through 3.H of the Accomplishment 
Instructions of Pratt & Whitney SB No. PW4ENG 72-799, Revision

[[Page 78883]]

1, dated October 14, 2010, to perform the BSIs for engines listed in 
paragraph(c)(1) of this AD.
    (k) Use paragraphs 3.A through 3.H of the Accomplishment 
Instructions of Pratt & Whitney SB No. PW4G-100-72-226, dated April 
22, 2010, to perform the BSIs for engines listed in paragraphs(c)(2) 
and (c)(3) of this AD.

Optional Terminating Action

    (l) As optional terminating action to the repetitive inspection 
requirements of this AD, install new 9th stage compressor stator 
segments, part number (P/N) 50S479-01, P/N 50S479-02, P/N 50S479-03, 
and P/N 50S479-04, and perform one of the following:
    (1) At the time the new 9th stage compressor stator segments are 
installed, replace the HPC drum rotor disk assembly with a new, 0 
cycle, HPC drum rotor disk assembly; or
    (2) At the time the new 9th stage compressor stator segments are 
installed, replace the 10th stage HPC disk with a new, 0 cycle, 10th 
stage HPC disk; or
    (3) Perform a one-time BSI or FPI for cracks in the AVT shelf 
slots on the 10th stage HPC disk of the HPC drum rotor disk assembly 
between 4,000 and 7,200 cycles-in-service since installation of the 
new 9th stage compressor stator segments.
    (i) If a crack is found, remove the HPC drum rotor disk assembly 
from service.
    (ii) If no crack is found, then no further inspections are 
required.
    (4) Guidance on installation of the new 9th stage compressor 
stator segments can be found in Pratt & Whitney SB No. PW4ENG 72-
801, Revision 1, dated September 8, 2010, for engines listed in 
paragraph(c)(1) of this AD and in Pratt & Whitney SB No. PW4G-100-
72-225 dated April 20, 2010, for engines listed in paragraphs(c)(2) 
and (c)(3) of this AD.

Alternative Methods of Compliance (AMOCs)

    (m) The Manager, Engine Certification Office, has the authority 
to approve AMOCs for this AD if requested using the procedures found 
in 14 CFR 39.19.

Related Information

    (n) Contact James Gray, Aerospace Engineer, Engine Certification 
Office, FAA, Engine and Propeller Directorate, 12 New England 
Executive Park, Burlington, MA 01803; e-mail: [email protected]; 
telephone (781) 238-7742; fax (781) 238-7199, for more information 
about this AD.

Material Incorporated by Reference

    (o) You must use Pratt & Whitney Service Bulletin (SB) No. PW4G-
100-72-226, dated April 22, 2010, and Pratt & Whitney SB No. PW4ENG 
72-799, Revision 1, dated October 14, 2010, to perform the borescope 
inspections required by this AD. The Director of the Federal 
Register approved the incorporation by reference of these documents 
in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Pratt 
& Whitney, 400 Main St., East Hartford, CT 06108; telephone (860) 
565-8770; fax (860) 565-4503, for a copy of this service 
information. You may review copies at the FAA, New England Region, 
12 New England Executive Park, Burlington, MA; or 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 November 17, 2010.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2010-31723 Filed 12-16-10; 8:45 am]
BILLING CODE 4910-13-P

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