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Proposed Rule

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

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

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AGENCY:

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

ACTION:

Notice of proposed rulemaking (NPRM).

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.

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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.

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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). Start Printed 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.

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List of Subjects in 14 CFR Part 39

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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:

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PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

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Authority: 49 U.S.C. 106(g), 40113, 44701.

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[Amended]

2. The FAA amends § 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 Start Printed Page 63512JT9D-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.

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Issued in Burlington, Massachusetts, on November 2, 2007.

Peter A. White,

Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service.

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[FR Doc. E7-22005 Filed 11-8-07; 8:45 am]

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