[4910-13-P] 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA-2012-0546; Directorate Identifier 2012-NE-15-AD; Amendment 

39-17253; AD 2012-22-16] 

R1N 2120-AA64 

Airworthiness Directives; Pratt & Whitney Division Turbofan Engines 

AGENCY: Federal Aviation Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: We are adopting a new airworthiness directive (AD) for all Pratt & 

Whitney Division PW4050, PW4052, PW4056, PW4060, PW4060A, PW4060C, 

PW4062, PW4062A, PW4!52, PW4156, PW4156A, PW4158, PW4160, PW4460, 

PW4462, and PW4650 turbofan engines, including models with any dash number suffix. 

This AD was prompted by 16 reports of damaged or failed 3rd stage low-pressure turbine 

(LPT) duct segments. This AD requires removing from service certain part numbers 

(PINs) of3rd stage LPT duct segments. We are issuing this AD to prevent failure of the 

3rd stage LPT duct segments, which could lead to LPT rotor damage, uncontained engine 

failure, and damage to the airplane. 

DATES: This AD is effective [INSERT DATE 35 DAYS AFTER DATE OF 

PUBLICATION IN THE FEDERAL REGISTER]. 

ADDRESSES: For service information identified in this AD, contact Pratt & Whitney, 

400 Main St., East Hartford, CT 06108; phone: 860-565-8770; fax: 860-565-4503. 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, call781-238-7125. 
Examining the AD Docket 

You may examine the AD docket on the Internet at http://wwvv.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 Wl2-140, 

1200 New Jersey Avenue SE., Washington, DC 20590. 

FOR FURTHER INFORMATION CONTACT: James Gray, Aerospace Engineer, 

Engine & Propeller Directorate, FAA, 12 New England Executive Park, Burlington, MA 

01803; phone: 781-238-7742; fax: 781-238-7199; e-mail: james.e.gray@faa.gov. 

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 July 11,2012 (77 FR 40822). That NPRM proposed to require 

removal from service of3rd stage LPT duct segments PINs 50N095; 50N095-001; 

50N235; 50N235-00I; 50N494-01; 50N494-001; 50N495-0i; and 50N495-001, at the 

next piece-part exposure after the effective date of the proposed AD. 

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. 

Agreement with the Proposed AD 

One commenter, Boeing, agreed with the intent of the proposed AD. 

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Request to Reference Pratt & Whitney Service Bulletin PW4ENG 72-488 

One commenter, FedEx Express, requested that we add a reference to Pratt & 

Whitney Service Bulletin PW4ENG 72-488 for a list of the engine serial nwnbers 

affected. We assume this request was made to add clarity. 

We do not agree. The AD applicability is for PW4000 engines with certain PIN 

3'' stage LPT duct segments installed. Although the Pratt & Whitney Service Bulletin 

does list engine serial numbers, it is not necessary to include this information in the AD. 

We did not change the AD. 

Conclusion 

We reviewed the relevant data, considered the comments received, and 

determined that air safety and the public interest require adopting the AD as proposed. 

Costs of Compliance 

We estimate that this AD will affect !51 engines installed on airplanes of U.S. 

registry. We estimate that no additional labor costs will be incurred to perform the 

required work as the work is done when the 3rd stage LPT duct segments are at piece-part 

exposure. The average labor rate is $85 per work-hour. Required parts will cost about 

$44,441 per engine. Based on these figures, we estimate the total cost of the AD to U.S. 

operators will be $6,710,591. 

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 

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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 - AIRWORTIDNESS DIRECTIVES 

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

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

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§ 39.13 [Amended] 

2. The FAA amends§ 39.13 by adding the following new airworthiness directive 

(AD): 

2012-22-16 Pratt & Whitney Division: Amendment 39-17253; Docket 

No. FAA-2012-0546; Directorate Identifier 2012-NE-15-AD. 

(a) Effective Date 

This AD is effective [INSERT DATE 35 DAYS AFTER DATE OF 

PUBLICATION IN THE FEDERAL REGISTER]. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to all Pratt & Whitney Division PW4050, PW4052, PW4056, 

PW4060,PW4060A,PW4060C,PW4062,PW4062A,PW4152,PW4156,PW4156A, 

PW4!58, PW4160, PW4460, PW4462, and PW4650 turbofan engines, including models 

with any dash number suffix, with 3rd stage low-pressure turbine (LPT) duct segments 

part numbers (PINs) 50N095; 50N095-00I; 50N235; 50N235-001; 50N494-0l; 50N494-

001; 50N495-0I; or 50N495-001, installed. 

(d) Unsafe Condition 

This AD was prompted by 16 reports of damaged or failed 3"' stage LPT duct 

segments. We are issuing this AD to prevent failure of the 3rd stage LPT duct segments, 

which could lead to LPT rotor damage, uncontained engine failure, and damage to the 

airplane. 

(e) Compliance 

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

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(I) 3'' Stage LPT Duct Segments Removal from Service 

At the next piece-part exposure after the effective date of this AD, remove from 

service 3'' stage LPT duct segments, PINs 50N095; 50N095-00I; 50N235; 50N235-001; 

50N494-0I; 50N494-001; 50N495-0l; and 50N495-00I. 

(g) Installation Prohibition 

After the effective date of this AD, do not install into any engine any 3rd stage 

LPT duct segment, PIN 50N095; 50N095-001; 50N235; 50N235-001; 50N494-01; 

50N494-00I; 50N495-0I; or 50N495-00I, that is at piece-part exposure. 

(h) Definition 

For the purpose of this AD, piece-part exposure is when the 3rd stage LPT duct 

segment is removed from the engine and completely disassembled. 

(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 

(1) For more information about this AD, contact James Gray, Aerospace 

Engineer, Engine & Propeller Directorate, FAA, 12 New England Executive Park, 

Burlington, MA 01803; phone: 781-238-7742; fax: 781-238-7199; e-mail: 

james.e.gray@faa.gov. 

(2) Pratt & Whitney Engine-Duct Segment, Third Stage LPT Assembly Service 

Bulletin No. PW4ENG 72-488 is related to this AD. 

(3) For service infonnation identified in this AD, contact Pratt & Whitney, 400 

Main St., East Hartford, CT 06108; phone: 860-565-8770; fax: 860-565-4503. You may 

review copies of the service information at the FAA, Engine & Propeller Directorate, 12 

New England Executive Park, Burlington, MA. For infonnation on the availability of this 

material at the FAA, call781-238-7125. 

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(k) Material Incorporated by Reference 

None. 

Issued in Burlington, Massachusetts, on October 29,2012. 

a&~m 'Ua.QQ_JJ()MdtSJ 

Colleen M. D' Allessandro, 

Assistant Manager, Engine & Propeller Directorate, 

Aircraft Certification Service. 

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