Airworthiness Directives; Pratt & Whitney (PW)Turbofan Engines

[Federal Register Volume 77, Number 57 (Friday, March 23, 2012)]
[Rules and Regulations]
[Pages 16916-16917]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-6952]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-1176; Directorate Identifier 2011-NE-35-AD; 
Amendment 39-16995; AD 2012-06-14]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney (PW)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 PW 
JT9D-7R4G2 and -7R4H1 turbofan engines. This AD was prompted by the 
determination that a new lower life limit for high-pressure turbine 
(HPT) 1st stage air seals, part number (P/N) 735907, is necessary. This 
AD establishes a new lower life limit for HPT 1st stage air seals, P/N 
735907, and requires removing them from service using a drawdown 
schedule. We are issuing this AD to prevent critical life-limited 
rotating engine part failure and damage to the airplane.

DATES: This AD is effective April 27, 2012.

ADDRESSES: You may review copies of the referenced 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: Ian Dargin, Aerospace Engineer, Engine 
& Propeller Directorate, 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 include an AD that would apply to the specified products. 
That NPRM published in the Federal Register on November 23, 2011 (76 FR 
72348). That NPRM proposed to require establishing a new lower life 
limit for HPT 1st stage air seals, P/N 735907, from 15,000 cycles-
since-new (CSN) to 9,000 CSN and to require removing them from service 
using a drawdown schedule.

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 as Written

    The Boeing Company and an individual commenter support the NPRM (76 
FR 72348, November 23, 2011) as written.

Request To Revise Applicability

    Commenter PW requested that we revise the applicability and summary 
sections of the AD to limit applicability to only the PW JT9D-7R4G2 and 
-7R4H1 turbofan engine models. We agree. In addition to the JT9D-7R4G2 
and -7R4H1 engines, the NPRM (76 FR 72348, November 23, 2011) 
incorrectly included JT9D-7R4D, -7R4D1, -7R4E, -7R4E1 and -7R4E4 engine 
models. We changed the AD by limiting the applicability to only the PW 
JT9D-7R4G2 and -7R4H1 turbofan engine models.

Request To Revise Removal Limits

    Commenter Federal Express requested that different removal 
(drawdown) limits be specified for the JT9D-7R4E1 and -7R4E1H engine 
models, based on the life limits listed in chapter 05 of the PW engine 
manual.
    We do not agree. We removed the JT9D-7R4E1 and -7R4E1H engine 
models from this AD in response to another comment. Therefore, the 
JT9D-7R4E1 and -7R4E1H engine models are no longer affected by this AD. 
However, as these air seals are installed on other engine models, we 
modified the installation prohibition paragraph to indicate that an air 
seal removed in accordance with this AD cannot be installed in any 
other engine. Further, we noted that all air seals identified in this 
AD, when used on the JT9D-7R4E1 and -7R4E1H engine models, have a 9,000 
CSN life limit.

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 28 Pratt & Whitney JT9D-7R4G2, 
and -7R4H1 turbofan engines installed on airplanes of U.S. registry. We 
also estimate that it will take 28.8 work-hours per engine to perform 
the actions required by this AD, and that the average labor rate is $85 
per work-hour.

[[Page 16917]]

Required parts will cost about $37,200 per engine. Based on these 
figures, we estimate the total cost of the AD to U.S. operators to be 
$1,110,144.

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 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 adding the following new airworthiness 
directive (AD):

2012-06-14 Pratt & Whitney: Amendment 39-16995; Docket No. FAA-2011-
1176; Directorate Identifier 2011-NE-35-AD.

(a) Effective Date

    This AD is effective April 27, 2012.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Pratt & Whitney JT9D-7R4G2 and -7R4H1 
turbofan engines.

(d) Unsafe Condition

    This AD was prompted by the determination that a new lower life 
limit of 9,000 cycles-since-new (CSN) for high-pressure turbine 
(HPT) 1st stage air seals, part number (P/N) 735907, is necessary. 
We are issuing this AD to prevent critical life-limited rotating 
engine part failure, and damage to the airplane.

(e) Compliance

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

(f) Removal of HPT 1st Stage Air Seals, P/N 735907

    Remove HPT 1st stage air seals, P/N 735907, from service as 
follows:
    (1) For air seals that have fewer than 6,500 CSN on the 
effective date of this AD, remove the air seals from service before 
exceeding 9,000 CSN.
    (2) For air seals that have 6,500 CSN or more on the effective 
date of this AD, do the following:
    (i) If the engine has a shop visit before the air seal exceeds 
9,000 CSN, remove the air seal from service before exceeding 9,000 
CSN.
    (ii) If the engine does not have a shop visit before the air 
seal exceeds 9,000 CSN, remove the air seal from service at the next 
shop visit, not to exceed 2,500 cycles from the effective date of 
this AD or 15,000 CSN, whichever occurs first.

(g) Installation Prohibition

    (1) After the effective date of this AD, do not install or 
reinstall into any engine any HPT 1st stage air seal, P/N 735907, 
removed from service in accordance with paragraph (f) of this AD.
    (2) After the effective date of this AD, do not install or 
reinstall into any JT9D-7R4G2 or JT9D-7R4H1 engine any HPT 1st stage 
air seal, P/N 735907, that exceeds the new life limit of 9,000 CSN.

(h) Engine Shop Visit Definition

    For the purposes of this AD, an engine shop visit is the 
induction of an engine into the shop after the effective date of 
this AD, where the separation of a major engine flange occurs, 
except that the following maintenance actions, or any combination 
thereof, are not considered engine shop visits:
    (1) Introduction of an engine into a shop solely for removal of 
the compressor top or bottom case for airfoil maintenance or 
variable stator vane bushing replacement.
    (2) Introduction of an engine into a shop solely for removal or 
replacement of the stage 1 fan disk.
    (3) Introduction of an engine into a shop solely for replacement 
of the turbine rear frame.
    (4) Introduction of an engine into a shop solely for replacement 
of the accessory gearbox or transfer gearbox, or both.
    (5) Introduction of an engine into a shop solely for replacement 
of the fan containment case.

(i) 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.

(j) Related Information

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

(k) Material Incorporated by Reference

    None.


    Issued in Burlington, Massachusetts, on March 16, 2012.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-6952 Filed 3-22-12; 8:45 am]
BILLING CODE 4910-13-P

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