

[Federal Register: November 9, 2007 (Volume 72, Number 217)]
[Proposed Rules]               
[Page 63510-63512]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr09no07-21]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-23742; Directorate Identifier 2005-NE-53-AD]
RIN 2120-AA64

 
Airworthiness Directives; Pratt & Whitney (PW) JT9D-7R4 Series 
Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede an existing airworthiness 
directive (AD) for PW JT9D-7R4 series turbofan engines. That AD 
currently requires removing certain reduced cooling flow 2nd stage high 
pressure turbine (HPT) vane assemblies installed in certain 2nd stage 
HPT vane cluster assemblies. It also requires a visual and a 
fluorescent penetrant inspection (FPI) of the 2nd stage HPT air seal 
assembly, P/N 815097. This proposed AD would require a visual and 
fluorescent penetrant inspection (FPI) of all part number (P/N) 2nd 
stage HPT air seal assemblies that were used with reduced cooling flow 
2nd stage HPT vane assemblies. This proposed AD results from the 
manufacturer identifying additional P/N air seal assemblies that are 
affected by the unsafe condition. We are proposing this AD to prevent 
uncontained failure of the 2nd stage HPT air seal assembly, leading to 
engine in-flight shutdown and damage to the airplane.

DATES: We must receive any comments on this proposed AD by January 8, 
2008.

ADDRESSES: Use one of the following addresses to comment on this 
proposed AD.
     Federal eRulemaking Portal: Go to http://www.regulations.gov
 and follow the instructions for sending your 

comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 1200 New Jersey Avenue, SE., West Building Ground 
Floor, Room W12-140, Washington, DC 20590-0001.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
     Fax: (202) 493-2251.
    Contact Pratt & Whitney, 400 Main St., East Hartford, CT 06108; 
telephone (860) 565-8770; fax (860) 565-4503, for the service 
information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT: Mark Riley, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; e-mail: 
mark.riley@faa.gov; telephone (781) 238-7758, fax (781) 238-7199.


SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2006-23742; 
Directorate Identifier 2005-NE-53-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light 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 
with FAA personnel concerning this proposed AD. Using the search 
function of the Web site, anyone can find and read the comments in any 
of our dockets, including, if provided, the name of the individual who 
sent the comment (or signed the comment on behalf of an association, 
business, labor union, etc.). You may review the DOT's complete Privacy 
Act Statement in the Federal Register published on April 11, 2000 (65 
FR 19477-78).

[[Page 63511]]

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 proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Operations office (telephone (800) 647-5527) is 
the same as the Mail address provided in the ADDRESSES section. 
Comments will be available in the AD docket shortly after receipt.

Discussion

    The FAA proposes to amend 14 CFR part 39 by superseding AD 2007-17-
21, Amendment 39-15180 (72 FR 48549, August 24, 2007). That AD requires 
removing reduced cooling flow 2nd stage HPT vane assemblies. It also 
requires a visual and an FPI of the 2nd stage HPT air seal assembly. 
That AD resulted from a report of an uncontained failure of the 2nd 
stage HPT air seal assembly, caused by the air seal assembly brace 
disengaging from the air seal, due to insufficient cooling air flow. 
That condition, if not corrected, could result in uncontained failure 
of the 2nd stage HPT air seal assembly, leading to engine in-flight 
shutdown and damage to the airplane.

Actions Since AD 2007-17-21 Was Issued

    Since we issued that AD, we determined that we need to expand the 
applicability of the AD to include all 2nd stage HPT air seal 
assemblies that were used with reduced cooling flow 2nd stage HPT vane 
assemblies, P/Ns 797282, 796972, 800082, 800072, 803182, 803282, and 
822582, installed in 2nd stage HPT vane cluster assemblies P/Ns 797592, 
797372, 799872, 799782, and 822572.

Relevant Service Information

    We have reviewed and approved the technical contents of Pratt & 
Whitney Alert Service Bulletin JT9D-7R4-A72-596, dated September 15, 
2005, that describes procedures for modifying the reduced cooling flow 
2nd stage HPT vane assemblies.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other products 
of this same type design. For that reason, we are proposing this AD, 
which would require at the next HPT module exposure:
     Removing the reduced cooling flow 2nd stage HPT vane 
assemblies.
     Visual and fluorescent penetrant inspections of the 2nd 
stage HPT air seal assemblies that have operated in an engine with 
reduced cooling flow 2nd stage HPT vane assemblies.

Costs of Compliance

    Because this proposed AD is superseding an existing AD to remove 
the seal assembly P/N, this proposed AD would not add any additional 
costs beyond the costs included in the original AD.

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 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 that the proposed AD:
    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); and
    3. Would 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 regulatory evaluation of the estimated costs to 
comply with this proposed AD. See the ADDRESSES section for a location 
to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Under the authority delegated to me by the Administrator, the 
Federal Aviation Administration 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 removing Amendment 39-15180 (72 FR 
48549, August 24, 2007), and by adding a new airworthiness directive to 
read as follows:

Pratt & Whitney (PW): Docket No. FAA-2006-23742; Directorate 
Identifier 2005-NE-53-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by January 8, 
2008.

Affected ADs

    (b) This AD supersedes AD 2007-17-21, Amendment 39-15180.

Applicability

    (c) This AD applies to Pratt & Whitney (PW) JT9D-7R4G2, -7R4E1, 
-7R4E4, and -7R4H1 series turbofan engines. These engines are 
installed on, but not limited to, Boeing 747-200, -300, 767-200, and 
Airbus A300-600 and A310-300 series airplanes.

Unsafe Condition

    (d) This AD results from the manufacturer identifying additional 
part numbers (P/N) air seal assemblies that are affected by the 
unsafe condition. We are issuing this AD to prevent uncontained 
failure of the 2nd stage high pressure turbine (HPT) air seal 
assembly, leading to engine in-flight shutdown and damage to the 
airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed at the next HPT module exposure after the effective 
date of this AD, unless the actions have already been done.
    (f) At the next HPT module exposure, remove reduced cooling flow 
2nd stage HPT vane assemblies P/Ns: 797282, 796972, 800082, 800072, 
803182, 803282, and 822582, installed in 2nd stage HPT vane cluster 
assemblies: P/Ns 797592, 797372, 799872, 799782, and 822572.
    (g) For 2nd stage HPT air seals that have operated in an engine 
with reduced cooling flow HPT vane assemblies, at the next HPT 
module exposure do the following:
    (1) Perform a onetime visual inspection of the 2nd stage HPT air 
seal assembly. The

[[Page 63512]]

JT9D-7R4 engine manual, Section 72-51-22, Inspection/Check-01, 
paragraphs 1.D.(1), 1.D.(4), and 1.D.(6) contains instructions for 
the visual inspection.
    (2) Perform a fluorescent penetrant inspection (FPI) of the 2nd 
stage HPT air seal assembly for cracks. The JT9D-7R4 engine manual, 
Section 72-51-00, Inspection/Check-03, contains instructions for the 
FPI.

Definition

    (h) For the purpose of this AD, we define an HPT module exposure 
as removing the 1st stage HPT rotor or the 2nd stage HPT rotor from 
the HPT case.

Alternative Methods of Compliance

    (i) The Manager, Engine Certification Office, has the authority 
to approve alternative methods of compliance for this AD if 
requested using the procedures found in 14 CFR 39.19.

Related Information

    (j) Pratt & Whitney Alert Service Bulletin JT9D-7R4-A72-596, 
dated September 15, 2005, contains information for modifying the 
reduced cooling flow 2nd stage HPT vane assemblies.
    (k) Contact Mark Riley, Aerospace Engineer, Engine Certification 
Office, FAA, Engine and Propeller Directorate, 12 New England 
Executive Park, Burlington, MA 01803; e-mail: mark.riley@faa.gov; 
telephone (781) 238-7758, fax (781) 238-7199, for more information 
about this AD.

    Issued in Burlington, Massachusetts, on November 2, 2007.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. E7-22005 Filed 11-8-07; 8:45 am]

BILLING CODE 4910-13-P
