[Federal Register Volume 77, Number 180 (Monday, September 17, 2012)]
[Rules and Regulations]
[Pages 57007-57010]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-22534]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0217; Directorate Identifier 2009-NE-23-AD; 
Amendment 39-17194; AD 2012-18-17]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Division 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 (Pratt & Whitney) PW4052, PW4056, 
PW4060, PW4062, PW4062A, PW4074, PW4077, PW4077D, PW4084D, PW4090, 
PW4090-3, PW4152, PW4156A, PW4158, PW4164, PW4168, PW4168A, PW4460, and 
PW4462 turbofan engines. That AD currently requires initial and 
repetitive fluorescent penetrant inspections (FPI) for cracks in the 
blade loading and locking slots of the high-pressure compressor (HPC) 
drum rotor disk assembly rear drum. This new AD requires the same 
actions, requires replacement of the 13th, 14th, and 15th stage HPC 
seals with redesigned HPC seals as an additional action, and adds an 
optional terminating action to the repetitive inspection requirements 
by allowing replacement of the entire HPC drum rotor disk assembly with 
a redesigned HPC drum rotor disk assembly. This AD was prompted by 
Pratt & Whitney developing a redesigned HPC drum rotor disk assembly 
for certain affected engine models. We are issuing this AD to prevent 
failure of the HPC drum rotor disk assembly, which could lead to an

[[Page 57008]]

uncontained engine failure, and damage to the airplane.

DATES: This AD is effective October 22, 2012.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of October 22, 
2012.
    The Director of the Federal Register approved the incorporation by 
reference of certain other publications listed in this AD as of October 
18, 2010 (75 FR 55459, September 13, 2010).

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 view this service information at the FAA, 
Engine & Propeller Directorate, 12 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: James Gray, Aerospace Engineer, Engine 
& Propeller Directorate, FAA, 12 New England Executive Park, 
Burlington, MA 01803; phone: 781-238-7742; 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 2010-18-13, Amendment 39-16427 (75 FR 55459, 
September 13, 2010). That AD applies to the specified products. The 
NPRM published in the Federal Register on May 24, 2012 (77 FR 30926). 
That NPRM proposed to retain all of the requirements of AD 2010-18-13. 
That NPRM also proposed to require replacement of the 13th, 14th, and 
15th stage HPC seals with redesigned seals and add an optional 
terminating action to the repetitive inspection requirement by allowing 
replacement of the HPC drum rotor disk assembly with a redesigned HPC 
drum rotor disk assembly.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comments received on the proposal 
and the FAA's response to each comment.

In Agreement With the Proposed AD

    The Boeing Company and FedEx Express are in agreement with the 
proposed AD.

Request To Allow for Previous Credit

    FedEx Express requested that we allow credit for prior compliance 
with the AD actions.
    We do not agree. The proposed AD already allows credit for prior 
compliance in paragraph (e), which states to comply within the 
compliance times specified unless already done. We did not change the 
AD.

Request To Reference the Latest Revisions of Two Service Bulletins 
(SBs)

    United Airlines, Korean Air, and Atlas Air, requested that we 
reference the latest revisions of two SBs which were revised since the 
proposed AD was issued.
    We agree. We now reference Pratt & Whitney SB No. PW4ENG 72-816, 
Revision 1, dated June 12, 2012, and Pratt & Whitney SB No. PW4G-100-
72-240, Revision 1, dated June 12, 2012, in the AD.

Request To Revise Paragraph (g)

    United Airlines requested that we change paragraph (g) of the 
proposed AD to only require use of paragraphs 1.A. through 1.C. of the 
Accomplishment Instructions of SB No. PW4ENG 72-816 since additional 
paragraphs of the SB are not needed to comply with the AD.
    We agree. We changed paragraphs (g)(1) and (g)(2) to only require 
use of paragraphs 1.A through 1.C. of that SB to comply with the AD.

Request To Add Previously Approved Alternate Methods of Compliance 
(AMOCs)

    Japan Airlines and Korean Air requested that we add the previously 
approved AMOCs to the AD. The commenters referenced two previously 
approved AMOCs related to taking credit for the inspections required by 
AD 2005-25-09 (70 FR 73358, December 12, 2005), and use of the disk 
replacement repair included in the PW4000 Engine Cleaning Inspection 
and Repair (CIR) Manual to return non-cracked stages of the drum rotor 
disk assembly to service.
    We do not agree. We did not list the previously approved AMOCs in 
the proposed AD because paragraph (j) of the proposed AD already allows 
use of previously approved AMOCs to paragraph (f) of the existing AD. 
Paragraph (f) was specified because the content of this paragraph did 
not change in the proposed AD supersedure. We did not change the AD.

Request To Revise Paragraph (f)(2)

    Atlas Air requested that we revise paragraph (f)(2) of the proposed 
AD to remove only the cracked disk in the HPC drum rotor disk assembly 
from service. The commenter stated that currently paragraph (f)(2) 
requires the entire drum rotor disk assembly to be removed from service 
if a crack is found. The commenter believes it would be acceptable to 
remove from service only the cracked disk in the drum rotor disk 
assembly and use the repair in the PW4000 Engine CIR manual to replace 
it with a serviceable disk.
    We partially agree. We agree that an acceptable level of safety 
would be maintained by returning the other stages of the drum rotor 
disk assembly to service if they were not cracked, if the cracked 
stages of the HPC drum rotor disk assembly were replaced by new disks 
per the disk replacement repairs in the PW4000 Engine CIR manual. We do 
not agree with revising the proposed AD because this is already an 
approved global AMOC covered under paragraph (j) of the proposed AD. We 
did not change the AD.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
the AD with the changes described previously.

Costs of Compliance

    We estimate that this AD will affect 911 engines installed on 
airplanes of U.S. registry. We also estimate that it will take about 1 
work-hour per engine to perform an inspection using an average labor 
rate of $85 per work-hour. We estimate that there are 770 PW4000-94'' 
and PW4000-100'' engines that will require replacement of 13th, 14th, 
and 15th stage HPC seals, at a parts cost of $3,000 per engine. No 
additional labor is assumed when the replacement is done at piece-part 
exposure of the HPC drum rotor disk assembly. The replacement parts 
cost of the redesigned HPC drum rotor disk assembly is $630,000. Based 
on these figures, we

[[Page 57009]]

estimate that the total cost of the AD to U.S. operators will be 
$2,387,435.

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),
    (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) 
2010-18-13, Amendment 39-16427 (75 FR 55459, September 13, 2010), and 
adding the following new AD:

2012-18-17 Pratt & Whitney Division: Amendment 39-17194; Docket No. 
FAA-2010-0217; Directorate Identifier 2009-NE-23-AD.

(a) Effective Date

    This airworthiness directive (AD) is effective October 22, 2012.

(b) Affected ADs

    This AD supersedes AD 2010-18-13, Amendment 39-16427 (75 FR 
55459, September 13, 2010).

(c) Applicability

    This AD applies to the following Pratt & Whitney Division (Pratt 
& Whitney) turbofan engines:
    (1) PW4000-94'' engine models PW4052, PW4056, PW4060, PW4062, 
PW4062A, PW4152, PW4156A, PW4158, PW4460, and PW4462, including 
those models with any dash number suffix, with a high-pressure 
compressor (HPC) drum rotor disk assembly listed in Table 1 to 
paragraph (c) of this AD installed.
    (2) PW4000-100'' engine models PW4164, PW4168, and PW4168A, with 
a HPC drum rotor disk assembly listed in Table 1 to paragraph (c) of 
this AD installed.
    (3) PW4000-112'' engine models PW4074, PW4077, PW4077D, PW4084D, 
PW4090, and PW4090-3, with a HPC drum rotor disk assembly listed in 
Table 1 to paragraph (c) of this AD installed.

    Table 1 to Paragraph (c)--Affected HPC Drum Rotor Disk Assemblies
------------------------------------------------------------------------
                                        Affected HPC drum rotor disk
           Engine models                    assembly part numbers
------------------------------------------------------------------------
PW4000-94''.......................  50H936; 50H936-002; 53H923-01;
                                     53H923-001; 53H973-01; 53H973-001;
                                     54H803-01; 54H803-001; 54H803-002;
                                     56H013-01; 56H013-001; 58H236-01
PW4000-100''......................  53H973-01; 53H973-001; 54H803-01;
                                     54H803-001; 54H803-002; 56H013-01;
                                     56H013-001; 58H236-01
PW4000-112''......................  55H722-01; 55H410-01; 57H010-01;
                                     57H210-01; 57H610-01; 57H910-01
------------------------------------------------------------------------

(d) Unsafe Condition

    This AD was prompted by Pratt & Whitney developing a redesigned 
HPC drum rotor disk assembly for certain affected engine models. We 
are issuing this AD to prevent failure of the HPC drum rotor disk 
assembly, which could lead to an uncontained engine failure, and 
damage to the airplane.

(e) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(f) Local Fluorescent Penetrant Inspection

    (1) Perform a local fluorescent penetrant inspection for cracks 
in the HPC drum rotor disk assembly rear drum blade loading and 
locking slots of the specific stages of the HPC drum rotor disk 
assemblies from which any of the blades are removed as specified in 
Table 2 to paragraph (f) of this AD.

   Table 2 to Paragraph (f)--Compliance Times and Service Bulletins by
                              Engine Model
------------------------------------------------------------------------
                              Inspect whenever . .   To inspect, use . .
      For engine model                  .                     .
------------------------------------------------------------------------
PW4074, PW4077, PW4077D,      Any of the HPC 13th   Paragraphs 1.A.
 PW4084D, PW4090, and PW4090-  or 14th stage         through 1.B. of the
 3.                            blades are removed    Accomplishment
                               during a shop visit.  Instructions of
                                                     PW4G-112-72-264,
                                                     Revision 2, dated
                                                     February 23, 2010.
PW4164, PW4168, and PW4168A.  Any of the HPC 13th,  Paragraphs 1.A.
                               14th, or 15th stage   through 1.C of the
                               blades are removed    Accomplishment
                               during a shop visit.  Instructions of
                                                     PW4G-100-72-186,
                                                     Revision 1, dated
                                                     September 2, 2004.
PW4052, PW4056, PW4060,       Any of the HPC 13th,  Paragraphs 1.A.
 PW4062, PW4062A, PW4152,      14th, or 15th stage   through 1.C. of the
 PW4156A, PW4158, PW4460,      blades are removed    Accomplishment
 and PW4462.                   during a shop visit.  Instructions of
                                                     PW4ENG 72-796,
                                                     dated June 11,
                                                     2009.
------------------------------------------------------------------------


[[Page 57010]]

     (2) Remove from service any HPC drum rotor disk assembly rear 
drum found with a crack in any of the blade loading and locking 
slots.

(g) Replacement of 13th, 14th, and 15th HPC Seals

    At the next piece-part exposure of the HPC drum rotor disk 
assembly after the effective date of this AD:
    (1) Replace the 13th, 14th, and 15th stage HPC seals with 
redesigned HPC seals of engines listed in paragraph (c)(1) of this 
AD in accordance with paragraphs 1.A through 1.C of the 
Accomplishment Instructions of Pratt & Whitney Service Bulletin (SB) 
No. PW4ENG 72-816, Revision 1, dated June 12, 2012.
    (2) Replace the 13th, 14th, and 15th stage HPC seals with 
redesigned HPC seals of engines listed in paragraph (c)(2) of this 
AD in accordance with paragraphs 1.A through 1.C of the 
Accomplishment Instructions of Pratt & Whitney SB No. PW4G-100-72-
240, Revision 1, dated June 12, 2012.

(h) Optional Terminating Action

    As optional terminating action to the repetitive inspection 
requirements of this AD:
    (1) Replace the HPC drum rotor disk assembly of engines listed 
in paragraph (c)(1) of this AD with a redesigned HPC drum rotor disk 
assembly in accordance with the Accomplishment Instructions of Pratt 
& Whitney SB No. PW4ENG 72-817, dated December 7, 2011.
    (2) Replace the HPC drum rotor disk assembly of engines listed 
in paragraph (c)(2) of this AD with a redesigned HPC drum rotor disk 
assembly in accordance with the Accomplishment Instructions of Pratt 
& Whitney SB No. PW4G-100-72-241, dated November 15, 2011.

(i) Definition

    For the purpose of this AD, piece-part exposure means that the 
HPC drum rotor disk assembly is removed from the engine and 
completely disassembled.

(j) 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. AMOCs approved previously in accordance with AD 2010-18-13, 
Amendment 39-16427 (75 FR 55459, September 13, 2010) are approved as 
AMOCs for the corresponding requirements in paragraph (f) of this 
AD.

(k) Related Information

    For more information about this AD, contact James Gray, 
Aerospace Engineer, Engine & Propeller Directorate, FAA, 12 New 
England Executive Park, Burlington, MA 01803; phone: 781-238-7742; 
fax: 781-238-7199; email: [email protected].

(l) 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.
    (3) The following service information was approved for IBR on 
October 22, 2012.
    (i) Pratt & Whitney Service Bulletin No. PW4G-100-72-240, 
Revision 1, dated June 12, 2012.
    (ii) Pratt & Whitney Service Bulletin No. PW4G-100-72-241, dated 
November 15, 2011.
    (iii) Pratt & Whitney Service Bulletin No. PW4ENG 72-816, 
Revision 1, dated June 12, 2012.
    (iv) Pratt & Whitney Service Bulletin No. PW4ENG 72-817, dated 
December 7, 2011.
    (4) The following service information was approved for IBR on 
October 18, 2010 (75 FR 55459, September 13, 2010).
    (i) Pratt & Whitney Service Bulletin No. PW4G-100-72-186, 
Revision 1, dated September 2, 2004.
    (ii) Pratt & Whitney Service Bulletin No. PW4G-112-72-264, 
Revision 2, dated February 23, 2010.
    (iii) Pratt & Whitney Service Bulletin No. PW4ENG 72-796, dated 
June 11, 2009.
    (5) 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.
    (6) You may view this service information at FAA, Engine & 
Propeller Directorate, 12 New England Executive Park, Burlington, 
MA. For information on the availability of this material at the FAA, 
call 781-238-7125.
    (7) You may view this service information 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 September 4, 2012.
Colleen M. D'Alessandro,
Assistant Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2012-22534 Filed 9-14-12; 8:45 am]
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