[Federal Register Volume 76, Number 134 (Wednesday, July 13, 2011)]
[Proposed Rules]
[Pages 41144-41145]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-17622]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0731; Directorate Identifier 2010-NE-39-AD
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Corp. (PW) JT9D-7R4H1 
Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for all 
PW JT9D-7R4H1 turbofan engines. This proposed AD would require removing 
certain high-pressure compressor (HPC) shafts before their certified 
life limits, and establishes a new, lower life-limit for these parts. 
This proposed AD was prompted by reports of cracks in five HPC shafts. 
We are proposing this AD to correct the unsafe condition on these 
products.

DATES: We must receive comments on this proposed AD by August 29, 2011.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

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 proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Office (phone: 800-647-5527) is in the ADDRESSES 
section. Comments will be available in the AD docket shortly after 
receipt.

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; e-mail: 
[email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2011-0731; 
Directorate Identifier 2010-NE-39-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    We received reports of five JT9D-7R4H1 engines containing an HPC 
shaft with cracks in the thread grooves of the rear shaft. These 
engines have the highest-thrust rating of the JT9D models, and were 
operating in hot environments. Higher operating metal

[[Page 41145]]

temperatures impose a greater low-cycle fatigue life debit for each 
operating cycle, requiring removing the affected shafts before reaching 
their certified life limits. All of the cracked shafts were from the 
same fleet and engine model. This condition, if not corrected, could 
result in failure of the HPC shaft that could lead to an uncommanded 
in-flight shutdown or a possible uncontained engine failure and damage 
to the airplane.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

Proposed AD Requirements

    This proposed AD would require:
     For HPC shafts that have more than 4,500 cycles-since-new 
(CSN) on the effective date of this AD, removing the HPC shaft from 
service within 500 cycles-in-service (CIS) after the effective date of 
this proposed AD or at the next shop visit after the effective date of 
this proposed AD, whichever occurs first.
     For HPC shafts that have 4,500 or fewer CSN on the 
effective date of this AD, removing the HPC shaft from service before 
exceeding 5,000 CSN.

Costs of Compliance

    We estimate that this proposed AD would not affect any engines 
installed on airplanes of U.S. registry.

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 determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 this proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under the 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, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    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]

    2. The FAA amends Sec.  39.13 by adding the following new 
airworthiness directive (AD):

Pratt & Whitney Corp: Docket No. FAA-2011-0731; Directorate 
Identifier 2010-NE-39-AD.

(a) Comments Due Date

    We must receive comments by August 29, 2011.

(b) Affected ADs

    None.

(c) Applicability

    Pratt & Whitney Corp (PW) JT9D-7R4H1 turbofan engines with a 
high-pressure compressor (HPC) shaft, part numbers (P/Ns) 808070 or 
808071, installed.

(d) Unsafe Condition

    This AD was prompted by reports of cracks in five HPC shafts. We 
are issuing this AD to correct the unsafe condition on these 
products.

(e) Compliance

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

(f) Engines With an HPC Shaft, P/N 808071, That Has More Than 4,500 
Cycles-Since-New (CSN)

    For engines with an HPC shaft, P/N 808071, that has more than 
4,500 CSN on the effective date of this AD, remove the HPC shaft 
from service within 500 cycles-in-service (CIS) after the effective 
date of the AD or at piece-part exposure, whichever occurs first.

(g) Engines With an HPC Shaft, P/N 808071, That Has 4,500 or Fewer CSN

    For engines with an HPC shaft, P/N 808071, that has 4,500 or 
fewer CSN on the effective date of this AD, remove the HPC shaft 
from service before exceeding 5,000 CSN.

(h) Engines With an HPC Shaft, P/N 808070, Removal From Service

    For engines with an HPC shaft, P/N 808070, remove the HPC shaft, 
P/N 808070, from service not later than 1,200 CSN.

(i) Installation Prohibition

    After the effective date of this AD, do not install or reinstall 
into any engine:
    (1) Any HPC shaft, P/N 808071, that is at piece-part exposure 
and exceeds the new lower life limit of 5,000 CSN, or
    (2) Any HPC shaft, P/N 808070, that is at piece-part exposure 
and exceeds the new lower life limit of 1,200 CSN.

(j) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, FAA, has the authority 
to approve AMOCs for this AD, if requested using the procedures 
found in 14 CFR 39.19. In accordance with 14 CFR 39.19.

(k) 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; e-mail: [email protected].

    Issued in Burlington, Massachusetts, on July 7, 2011.
Peter A. White,
Acting Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-17622 Filed 7-12-11; 8:45 am]
BILLING CODE 4910-13-P