Airworthiness Directives; Pratt & Whitney Division Turbofan Engines

[Federal Register Volume 77, Number 173 (Thursday, September 6, 2012)]
[Rules and Regulations]
[Pages 54791-54793]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-21821]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0228; Directorate Identifier 2012-NE-09-AD; 
Amendment 39-17179; AD 2012-18-03]
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 adopting a new airworthiness directive (AD) for certain 
Pratt & Whitney Division PW4000-94'' and PW4000-100'' turbofan engines 
having a 1st stage high-pressure turbine (HPT) seal support, part 
number (P/N) 55K601 (contained within assembly P/N 55K602-01) or P/N 
50K532 (contained within assembly P/N 50K530-01), installed. This AD 
was prompted by 58 reports of cracked 1st stage HPT air seal rings, 
including 15 in-flight engine shutdowns. This AD requires removal and 
replacement of the 1st stage HPT seal support and inspection of the 1st 
stage HPT air seal ring. We are issuing this AD to prevent failure of 
the 1st stage HPT air seal ring, which could lead to an internal oil 
fire, uncontained engine failure, and damage to the airplane.

DATES: This AD is effective October 11, 2012.

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 include an AD that would apply to the specified products. 
That NPRM published in the Federal Register on April 20, 2012 (77 FR 
23637). That NPRM proposed to require removal and replacement of the 
1st stage HPT seal support and inspection of the 1st stage HPT air seal 
ring.

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.

Support for the NPRM

    Commenter The Boeing Company supports the contents of the proposed 
AD (77 FR 23637, April 20, 2012) as written.

Request To Add Credit for Prior Compliance

    FedEx Express (FedEx) requested that the AD include credit for 
previous compliance.
    We agree. We added ``Comply with this AD the next time the HPT 
module is removed from the engine, unless already done'' to paragraph 
(e) of the AD.

Request To Change Compliance to Next Piece-Part Exposure

    FedEx requested that we clarify that the required removal and 
inspections occur when the part is completely disassembled and at the 
piece-part level.
    We do not agree. Removal of the 1st stage HPT seal support and 
inspection of the 1st stage HPT air seal ring are required when the HPT 
module is removed from the engine, which is not necessarily when the 
parts are at the piece-part level. Performing the actions the next time 
the HPT module is removed is required to maintain an acceptable level 
of safety for the fleet. We did not change the AD.

Request To Add the P/N of the Affected 1st Stage HPT Air Seal Ring

    Lufthansa Technik AG requested that we add the P/N of the 1st stage 
HPT air seal ring that requires inspection to paragraph (e)(2) of the 
proposed AD (77 FR 23637, April 20, 2012). The commenter states that 
there are two air seals in this area of the engine and clarification 
would help avoid confusion over which one requires inspection.
    We agree. We revised paragraph (e)(2) of the AD to include 1st 
stage HPT air seal ring, P/N 50L664.

Request To Change Compliance Time

    Martinair requested that paragraph (e) of the proposed AD (77 FR 
23637, April 20, 2012) be changed from ``* * * the next time that the 
engine is separated at the M-flange and the HPT module is removed from 
the engine'' to ``* * * the next time the HPT module is removed from 
the engine.'' The commenter states that the wording is confusing and 
may be interpreted that one is allowed to separate the engine at the M-
flange, without intending to remove the HPT module from the engine, and 
therefore the support would not require replacement.
    We agree. Including reference to the M-flange is redundant and not 
required, since the M-flange must be separated for the HPT module to be 
removed from the engine. We changed paragraph (e) of the AD to ``comply 
with this AD the next time that the HPT module is removed from the 
engine.''

Request To Reference the Latest Service Information

    Pratt & Whitney (P&W) requested that the AD reference the latest 
versions of service bulletins (SBs) PW4ENG 72-721 and PW4G-100-72-166 
because they were revised since the proposed AD (77 FR 23637, April 20, 
2012) was published.
    We disagree. The service information is only included as related 
information and is not incorporated by reference. Therefore, it is not 
necessary to specify a revision level and date of the service 
information in the AD. The proposed AD did include the revision level 
and date, but we modified the AD to remove those details.

[[Page 54792]]

Request To Revise the P/Ns of the 1st Stage HPT Seal Support

    Martinair, United, and P&W requested that the P/Ns of the 1st stage 
HPT seal support be changed because the 1st stage HPT seal support P/N 
is not generally tracked by itself, although the assembly P/N is. One 
commenter recommended mandating full incorporation of P&W SBs PW4ENG 
72-721 and PW4G-100-72-166, while another commenter recommended 
including the assembly P/Ns.
    We partially agree. We agree that the assembly P/Ns should be 
included for clarity because the 1st stage HPT seal support is not 
generally tracked by itself. The assembly includes the support and the 
mating brush seal. Even though they are sold as sets and generally 
tracked together, it is important to note that the unsafe condition has 
been identified on the HPT seal support and not the brush seal. We 
disagree that the SBs should be incorporated by reference because there 
are multiple acceptable methods of performing the actions required by 
the AD. We changed paragraph (e)(1) of the AD to ``Remove the 1st stage 
HPT seal support, P/N 55K601 (contained within assembly P/N 55K602-01) 
or P/N 50K532 (contained within assembly P/N 50K530-01), from service 
and replace it with a serviceable 1st stage HPT seal support.''

Request To Revise the Cost of Compliance

    United requested that we revise the costs of compliance because the 
latest parts cost is $48,695, not $45,723, as stated in the proposed AD 
(77 FR 23637, April 20, 2012).
    We agree. We included the latest parts costs in the Costs of 
Compliance paragraph of 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. We also determined that, 
other than the updated parts cost, these changes will not increase the 
economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

    We estimate that this AD will affect 446 P&W PW4000-94'' and 
PW4000-100'' turbofan engines installed on airplanes of U.S. registry. 
We also estimate that it will take about 3 work-hours to perform the 
removal and replacement of the 1st stage HPT seal support, and the 
removal, inspection, and replacement if necessary of the 1st stage HPT 
air seal ring. The average labor rate is $85 per work-hour. Required 
parts will cost about $48,695 per engine. Based on these figures, we 
estimate the total cost of the AD to U.S. operators to be $21,831,700.

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

    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, 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 adding the following new airworthiness 
directive (AD):

2012-18-03 Pratt & Whitney Division: Amendment 39-17179; Docket No. 
FAA-2012-0228; Directorate Identifier 2012-NE-09-AD.

(a) Effective Date

    This AD is effective October 11, 2012.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to the following Pratt & Whitney Division 
turbofan engines:
    (1) PW4000-94'' engine models PW4050, PW4052, PW4056, PW4152, 
PW4156, PW4650, PW4060, PW4060A, PW4060C, PW4062, PW4062A, PW4156A, 
PW4158, PW4160, PW4460, and PW4462, including models with any dash-
number suffix, with a 1st stage high-pressure turbine (HPT) seal 
support, part number (P/N) 55K601 (contained within assembly P/N 
55K602-01) or P/N 50K532 (contained within assembly P/N 50K530-01), 
installed.
    (2) PW4000-100'' engine models PW4164, PW4164C, PW4164C/B, 
PW4168, and PW4168A with a 1st stage HPT seal support, P/N 55K601 
(contained within assembly P/N 55K602-01) or P/N 50K532 (contained 
within assembly P/N 50K530-01), installed.

(d) Unsafe Condition

    This AD was prompted by 58 reports of cracked 1st stage HPT air 
seal rings, including 15 in-flight engine shutdowns. We are issuing 
this AD to prevent failure of the 1st stage HPT air seal ring, which 
could lead to an internal oil fire, uncontained engine failure, and 
damage to the airplane.

(e) Compliance

    Comply with this AD the next time the HPT module is removed from 
the engine, unless already done.
    (1) Remove the 1st stage HPT seal support, P/N 55K601 (contained 
within assembly P/N 55K602-01) or P/N 50K532 (contained within 
assembly P/N 50K530-01), from service and replace it with a 
serviceable 1st stage HPT seal support.
    (2) Remove the 1st stage HPT air seal ring, P/N 50L664, from the 
engine and fluorescent-penetrant-inspect, or eddy current-inspect, 
it for cracks. If found cracked, remove the 1st stage HPT air seal 
ring from service.

(f) Definition

    For the purpose of this AD, a serviceable 1st stage HPT seal 
support is one that has a P/N that is not listed in this AD.

[[Page 54793]]

(g) 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.

(h) Related Information

    (1) For more information about this AD, contact James Gray, 
Aerospace Engineer, FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; phone: 781-238-7742; 
fax: 781-238-7199; email: [email protected].
    (2) Pratt & Whitney Service Bulletin (SB) No. PWENG 72-721 and 
SB No. PW4G-100-72-166, pertain to the subject of this AD.
    (3) For service information identified in this AD, contact Pratt 
& Whitney, 400 Main St., East Hartford, CT 06108; phone: 860-565-
8770; fax: 860-565-4503.

(i) Material Incorporated by Reference

    None.

    Issued in Burlington, Massachusetts, on August 16, 2012.
Colleen M. D'Alessandro,
Assistant Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2012-21821 Filed 9-5-12; 8:45 am]
BILLING CODE 4910-13-P

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