I Docket No. F AA-20 13-0072; Directorate Identifier 20 13-NE-04-AD; Amendment 

39-18017; AD 2014-23-01] 

RIN 2120-AA64 

Airworthiness Directives; Pratt & Whitney Division Turbofan Engines 

AGENCY: Federal Aviation Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: We are superseding airworthiness directive (AD) 2013-15-09 for all Pratt 

& Whitney Division (PW) PW4074, PW4074D, PW4077, PW4077D, PW4084D, 

PW4090, and PW4090-3 turbofan engine models with certain second-stage high-pressure 

turbine (HPT) air seals installed. AD 2013-15-09 required initial and repetitive 

inspections for cracks in second-stage HPT air seals. This new AD expands the 

applicability of AD 2013-15-09 to include additional part numbers (PINs), requires 

removal of the mating hardware if the second-stage HPT air seal is found with a throughcrack, and adds a mandatory terminating action. This AD was prompted by reports of 

cracking in the original location on two additional PINs and reports of through-cracks in a 

new location in the second-stage HPT air seal. We are issuing this AD to prevent failure 

of the second-stage HPT air seal, which could lead to uncontained engine failure and 

damage to the airplane. 

DATES: This AD is effective [on December 26, 2014). 

The Director of the Federal Register approved the incorporation by reference of a 

certain publication listed in this AD as of September 17,2013 (78 FR 49111, August 13, 

2013 ). 
Division, 400 Main St., East Hartford, CT 061 08; phone: (860) 565-8770; fax: (860) 565-

4503. You may view this service information at the FAA, Engine & Propeller 

Directorate, 12 New England Executive Park, Burlington, MA. For information on the 

availability ofthis material at the FAA, call (781) 238-7125. 

Examining the AD Docket 

You may examine the AD docket on the Internet at http://www.regulations.gov by 

searching for and locating Docket No. F AA-20 13-0072; 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 ofTransportation, 

Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 

Jersey Avenue SE., Washington, DC 20590. 

FOR FURTHER INFORMATION CONTACT: Jo-Ann Theriault, Aerospace 

Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New 

England Executive Park, Burlington, MA 01803; phone: 781-238-7105; fax: 781-238-

7199; email: jo-ann.theriault@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Discussion 

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to 

supersede AD 2013-15-09, Amendment 39-17525 (78 FR 49111 , August 13, 20 13), 

("AD 2013-15-09"). AD 2013-15-09 applied to all PW PW4074, PW4074D, PW4077, 

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location in two additional second-stage HPT air seals. Pratt & Whitney developed a 

redesigned second-stage HPT air seal that corrects the cracking condition in both 

locations. 

The NPRM proposed to require initial and repetitive inspections for cracks in an 

expanded population of second-stage HPT air seals, and removal of air seals that fail 

inspection. The NPRM also proposed to require removal of the mating hardware if the 

second-stage HPT air seal is found with a through-crack, and a mandatory terminating 

action to the repetitive inspection requirements. We are issuing this AD to correct the 

unsafe condition on these products. 

Comments 

We gave the public the opportunity to participate in developing this AD. The 

following presents the comments received on the NPRM (79 FR 32500, June 5, 2014) 

and the FAA's response to each comment. 

Request to Correct PIN 

All Nippon Airways (ANA), Japan Airlines, United Airlines (UA), and PW 

requested that we correct the reference in the NPRM (79 FR 32500, June 5, 2014) to the 

PIN for the second-stage HPT air seal from 50L041 to 54L041. 

We agree. We corrected the reference to the second-stage HPT air seal PIN in this 

AD. 

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includes air seal detail, PIN 54L043. This AD applies to the entire second-stage HPT air 

seal, including all of its details. We did not change this AD. 

Request to Change Compliance Time 

ANA, PW, and UA requested that the compliance interval in paragraph (e)(2)(i) 

ofthe NPRM (79 FR 32500, June 5, 2014) be increased from 100 cycles-in-service (CIS) 

to 1,000 CIS. The commenters indicated that this AD should be consistent with AD 2013-

15-09, which specifies that the eddy current inspection (ECI) or initial fluorescentpenetrant inspection (FPI) should be performed within I ,000 cycles after the effective 

date of the AD. 

We agree. Performing an ECI or initial FPI within 1 ,000 cycles of September 17, 

2013, the effective date of AD 2013-15-09, maintains an acceptable level of safety. We 

changed paragraph (e)(2)(i) of this AD to read: "Perform an initial eddy current 

inspection (ECI) for cracks within 1,000 cycles-in-service after September 17, 2013, or 

before further flight, whichever occurs later." 

Request to Update Service Information 

ANA and PW asked that we update the reference to the service information from 

PW Service Bulletin (SB) No. PW4G-112-A72-332, Revision 2, dated April 9, 2014, to PW SB No. PW4G-112-A72-332, Revision 3, dated June 25,2014. 

We agree. We updated the service information reference in the Related 

Information paragraph in this AD to reflect the most current revision of SB No. PW 4G112-A 72-332. 

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propagated through the web of the forward flange outer diameter of the second-stage 

HPT air seal. 

We disagree. If a crack is found in the second-stage HPT air seal, then the life of 

mating hardware is adversely affected to the point that the mating hardware must be 

removed. The first-stage HPT air seal is not a life-limited part like the mating hardware 

we require to be removed if a crack is found. The first-stage HPT air seal, therefore, may 

be retained unless it is found damaged in the course of removing the rest of the mating 

hardware. We did not change this AD. 

Request to Develop Tracking Process for Parts Being Removed from Service 

UA requested that this AD consider record-keeping for the results of the FPI for 

second-stage HPT air seals that are being removed from service. UA commented that 

inspecting parts being removed from service is not common practice and that the burden 

of showing compliance to this AD rests with the operator and appropriate paper records 

need to be maintained. While the commenter did not request a specific change to this AD, 

we regard the comment as a reference to the lack of a standard industry practice for 

inspecting parts that are being removed from service. This refers to the second-stage HPT 

air seals, PIN 54L041, which are subject to an FPI after removal from service. 

We partially agree. We agree that inspecting parts removed from service for their 

impact on other parts is not common practice. However, operators must maintain 

adequate records of the maintenance they perform to show that the product has been 

properly maintained and is eligible for return to service as airworthy. We disagree that we 

need to impose additional record keeping requirements on operators to ensure that they 

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parts, i.e., first-stage HPT hubs, second-stage HPT hubs, and second-stage HPT blade 

retaining plates, that may have been mated previously to a cracked second-stage HPT air 

seal. UA noted that the continued serviceability of these spare parts depends on the result 

of the inspection of the second-stage HPT air seal that the parts were mated to while in 

service. UA would like procedures established to identify, tag, and mark these spare 

parts. UA noted that such procedures are not standardized within industry. UA also 

suggested that PW SB No. PW4G-112-A72-330 be revised to add some kind of marking 

to notate serviceable spare parts. 

We partially agree. We do not find the need to mandate a procedure to track these 

spare parts. Each operator should establish its own process for tracking its spare parts. 

We did not change this AD. 

We agree, however, that mating hardware previously installed with cracked 

second-stage HPT air seals is not eligible for installation as airworthy. We changed this 

AD to establish an installation prohibition to clarify that life-limited parts previously 

mated to a cracked second-stage HPT air seal, PIN 54L041, cannot be reinstalled. We 

added Installation Prohibition paragraph (f)(2) to this AD, which states: "After the 

effective date of this AD, do not install any spare first-stage HPT hub, second-stage HPT 

hub, or second-stage HPT blade retaining plate that was previously mated in service to a 

second-stage HPT air seal, PIN 54L041 , that was found to have a through-crack in the 

front forward fillet radius, into any engine." 

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50L960 and 50L976, because the ECI probe is not compatible with the geometry of those 

PINs. Also, removal of these parts at the next piece-part exposure without interim 

inspections maintains an acceptable level of safety. We did not change this AD. 

Agreement with this AD 

The Boeing Company expressed support for the NPRM (79 FR 32500, June 5, 

2014) as proposed. 

Conclusion 

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

determined that air safety and the public interest require adopting this AD with the 

changes described previously. We also determined that these changes will not increase 

the economic burden on any operator or increase the scope of this AD. 

Costs of Compliance 

We estimate that this AD affects 116 engines installed on airplanes ofU.S. 

registry. We also estimate that it will take about 5 hours to perform the inspection 

required by this AD. The average labor rate is $85 per hour. We estimate that two engines 

will also require removal of the first-stage HPT hub, second-stage HPT hub, and secondstage HPT blade retaining plate. We estimate that parts will cost about $698,920 per 

engine. Based on these figures, we estimate the total cost of this AD on U.S. operators to 

be $23,420,020. 

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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), 

(3) Will not affect intrastate aviation in Alaska to the extent that it justifies 

making a regulatory distinction, 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. 

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

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

§ 39.13 [Amended] 

2. The FAA amends § 39.13 by removing Airworthiness Directive (AD) 2013-15-

09, Amendment 39-17525 (78 FR 49111, August 13, 2013), and adding the following 

new AD: 

****-**->"' Pratt & Whitney Division: Amendment 39-**; Docket 

No. FAA-2013-0072; Directorate Identifier 2013-NE-04-AD. 

(a) Effective Date 

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

PUBLICATION IN THE FEDERAL REGISTER]. 

(b) Affected ADs 

This AD supersedes AD 2013-15-09, Amendment 39-17525 (78 FR 49111, 

August 13, 2013). 

(c) Applicability 

This AD applies to all Pratt & Whitney Division (PW) PW4074, PW4074D, 

PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 turbofan engine models with 

second-stage high-pressure turbine (HPT) air seal, part number (PIN) 54L041 , 50L960, or 

50L976, installed. 

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

(1) At the next piece-part exposure after the effective date of this AD, do the 

following: 

(i) Remove from service second-stage HPT air seals, PINs 50L960, 50L976, and 

54L041. 

(ii) Perform a fluorescent-penetrant inspection (FPI) of the second-stage HPT air 

seal, PIN 54 L041, for a through-crack in the front forward fillet radius. 

(iii) If a through-crack in the front forward fillet radius is found, remove the firststage HPT hub, second-stage HPT hub, and second-stage HPT blade retaining plate from 

service. Do not reinstall the first-stage HPT hub, second-stage HPT hub, or second-stage 

HPT blade retaining plate into any engine. 

(2) For engines with second-stage HPT air seals, PIN 54L041, installed, perform 

initial and repetitive inspections for cracks on-wing until the part is removed from the 

engine as follows: 

(i) Perform an initial eddy current inspection (ECI) for cracks within 1 ,000 

cycles-in-service after September 17, 2013, or before further flight, whichever occurs 

later. 

(ii) Thereafter, repeat the ECI every 1,200 cycles since last inspection, or fewer, 

depending on the results of the inspection. 

(iii) Use section 4.0 of the appendix of PW Alert Service Bulletin (ASB) No. 

PW4G-112-A72-330, Revision 2, dated July 11, 2013, to perform the inspection and use 

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(j) Related Information 

(1) For more information about this AD, contact Jo-Ann Theriault, Aerospace 

Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New 

England Executive Park, Burlington, MA 01803; phone: 781-238-7105; fax: 781-238-

7199; email: jo-ann.theriault@faa.gov. 

(2) PW Service Bulletin (SB) No. PW4G-112-72-332, Revision 3, dated June 25, 

2014, which is not incorporated by reference in this AD, can be obtained from PW, using 

the contact information in paragraph (k)(3) of this AD. This SB provides guidance on 

how to replace the second-stage HPT air seal with an air seal that is more resistant to low 

cycle fatigue cracks. 

(k) Material Incorporated by Reference 

(I) The Director of the Federal Register approved the incorporation by reference 

(TBR) ofthe service information listed in this paragraph under 5 U.S.C. 552(a) and I CFR 

part 51. 

(2) You must use this service information as applicable to do the actions required 

by this AD, unless the AD specifies otherwise. 

(3) The following service information was approved for IBR on September 17, 

2013 (78 FR 49111, August 13, 2013). 

(i) Pratt & Whitney (PW) Alert Service Bulletin No. PW4G-112-A 72-330, 

Revision 2, dated July 11 ,2013. 

(ii) Reserved. 

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Directorate, 12 New England Executive Park, Burlington, MA. For information on the 

availability ofthis material at the FAA, call 781-238-7125. 

(6) You may view this service information 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/ibrlocations.html. 

Issued in Burlington, Massachusetts, on October 30, 2014. 

CJJ /ltV'- Y)ll, D iJJJ!_ /fA!ltA k 

Colleen M. D'Alessandro, 

Assistant Directorate Manager, Engine & Propeller Directorate, 

Aircraft Certification Service. 

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