AD 2009-04-18

The FAA is adopting a new airworthiness directive (AD) for PW models JT9D-7, -7A, -7AH, -7H, -7F, and -7J turbofan engines. This AD requires initial and repetitive borescope inspections of the 2nd stage high-pressure turbine (HPT) rotor and stator assembly. This AD results from an uncontained failure of a 2nd stage HPT rotor disk that caused the engine to separate from the airplane. We are issuing this AD to prevent failure of the 2nd stage HPT rotor disk, which could result in uncontained engine failure, damage to the airplane, and the engine separating from the airplane.

Final rule.

2009-04-18 Pratt & Whitney: Amendment 39-15824. Docket No. FAA-2008- 0759; Directorate Identifier 2008-NE-02-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective May 5, 2009.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Pratt & Whitney (PW) JT9D-7, -7A, -7AH, - 7H, -7F, and -7J turbofan engines. These engines are installed on, but not limited to, Boeing 747 series airplanes.

Unsafe Condition

(d) This AD results from an uncontained failure of a 2nd stage high-pressure turbine (HPT) rotor disk that caused the engine to separate from the airplane. We are issuing this AD to prevent failure of the 2nd stage HPT rotor disk, which could result in uncontained engine failure, damage to the airplane, and the engine separating from the airplane.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.Initial Borescope Inspection

(f) Within 100 cycles-in-service (CIS) after the effective date of this AD, or within 1,000 CIS after the last installation of the second stage HPT vanes, whichever occurs later, do the following:
(1) Use the Accomplishment Instructions of PW Alert Service Bulletin (ASB) JT9D A6488, Revision 1, dated April 18, 2008, to borescope-inspect the 2nd stage HPT rotor and stator assembly either on-wing or in the shop.
(2) If you see any damage or contact between the 2nd stage HPT vanes and the 2nd stage HPT rotor, remove the engine from service.

Repetitive Borescope Inspection

(g) Thereafter, within 1,000 cycles-since-last inspection, do the following:
(1) Use the Accomplishment Instructions of PW ASB JT9D A6488 Revision 1, dated April 18, 2008, to borescope-inspect the 2nd stage HPT rotor and stator assembly either on-wing or in the shop.
(2) If you see any damage or contact between the 2nd stage HPT vanes and the 2nd stage HPT rotor,remove the engine from service.

Optional Terminating Action

(h) Installing the 2nd stage HPT vanes as specified in paragraphs 1.B.(1) through 1.B.(32) of Section 72-51-00, Assembly -02 of the JT9D-7 Engine Manual Revision 122, dated February 15, 2008, terminates the repetitive inspection requirement specified in paragraph (g) of this AD.

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) Contact Kevin Dickert, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: kevin.dickert@faa.gov; telephone (781) 238-7117, fax (781) 238-7199, for more information about this AD.

Material Incorporated by Reference

(k) You must use the service information specified in the following Table 1to perform the actions required by this AD. The Director of the Federal Register approved the incorporation by reference of the documents listed in the following Table 1 in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Contact Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone (860) 565-8770; fax (860) 565-4503, for a copy of this service information. You may review copies at the FAA, New England Region, 12 New England Executive Park, Burlington, MA; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

Table 1--Incorporation by Reference

Service information No.
Page
Revision
Date

Pratt & Whitney JT9D Engine Maintenance Manual PN 770408, Section 72-51-00, Assembly -02
Total Pages 36
1001 through 1036
122
February 15, 2008.
Pratt & Whitney PW ASB JT9D A6488, Revision 1, dated April 18, 2008.
All
1
April 18, 2008.
Total Pages - 21

The FAA proposed to amend 14 CFR part 39 with a proposed AD. The proposed AD applies to PW models JT9D-7, -7A, - 7AH, -7H, -7F, and -7J turbofan engines. We published the proposed AD in the Federal Register on July 10, 2008 (73 FR 39627). That action proposed to require an initial and repetitive borescope inspection of the 2nd stage HPT vane assembly.

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 AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone (800) 647-5527) is provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.
We provided the public the opportunity to participate in the development of this AD. We have considered the comment received.
One commenter asks us to change the compliance time from "cycles- since-overhaul'' to "cycles-since-last installation of the second stage HPT vanes.'' The commenter states that second stage HPT vanes might be removed and replaced at times other than module overhaul, such as for module repair.
We agree. We changed paragraph (f) of the proposed AD from "Within 100 cycles-in-service (CIS) after the effective date of this AD, or within 1,000 CIS after the last HPT module overhaul * * *'' to "Within 100 cycles-in-service (CIS) after the effective date of this AD, or within 1,000 CIS after the last installation of the second stage HPT vanes * * *''

Conclusion

We have carefully reviewed the available data, including the comment received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We have determined that these changes will neither increase the economic burden on any operatornor increase the scope of the AD.

Costs of Compliance

We estimate that this AD will affect 240 engines installed on airplanes of U.S. registry. We also estimate that it will take about 5 work-hours per engine to perform the proposed actions, that each engine might require two inspections, and that the average labor rate is $80 per work-hour. Based on these figures, we estimate the total cost of the AD to U.S. operators to be $192,000.

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 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); and
(3) 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.
We prepared a summary of the costs to comply with this AD and placed it in the AD Docket. You may get a copy of this summary at the address listed under ADDRESSES.

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 Federal Aviation Administration amends 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: