This section of the FEDERAL REGISTER

contains regulatory documents having general

applicability and legal effect, most of which

are keyed to and codified in the Code of

Federal Regulations, which is published under

50 titles pursuant to 44 U.S.C. 1510.

The Code of Federal Regulations is sold by

the Superintendent of Documents.

Rules and Regulations Federal Register

27889 

Vol. 83, No. 116 

Friday, June 15, 2018 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2017–0817; Product 

Identifier 2017–NE–30–AD; Amendment 

39–19314; AD 2018–13–02] 

RIN 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 (PW) PW4052, 

PW4056, PW4060, PW4062, PW4062A, 

PW4152, PW4156A, PW4158, PW4460, 

and PW4462 turbofan engine models, 

including engines identified with 

suffixes –1C, –1E, –3, –3A, or –3B. This 

AD was prompted by the discovery of 

multiple cracked 4th stage low-pressure 

turbine (LPT) air seals in the fleet. This 

AD requires removal from service of 

certain 4th stage LPT air seals. We are 

issuing this AD to address the unsafe 

condition on these products. 

DATES: This AD is effective July 20, 

2018. 

ADDRESSES: For service information 

identified in this final rule, contact Pratt 

& Whitney Division, 400 Main St., East 

Hartford, CT 06118; phone: 800–565– 

0140; fax: 860–565–5442. You may view 

this service information at the FAA, 

Engine and Propeller Standards Branch, 

1200 District Avenue, Burlington, MA 

01803. For information on the 

availability of this material at the FAA, 

call 781–238–7759. It is also available 

on the internet at http://

www.regulations.gov by searching for 

and locating Docket No. FAA–2017– 

0817. 

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. FAA–2017– 

0817; or in person at Docket Operations 

between 9 a.m. and 5 p.m., Monday 

through Friday, except Federal holidays. 

The AD docket contains this final rule, 

the regulatory evaluation, any 

comments received, and other 

information. The address for Docket 

Operations (phone: 800–647–5527) is 

U.S. Department of Transportation, 

Docket Operations, M–30, West 

Building Ground Floor, Room W12–140, 

1200 New Jersey Avenue SE, 

Washington, DC 20590. 

FOR FURTHER INFORMATION CONTACT: JoAnn Theriault, Aerospace Engineer, 

ECO Branch, FAA, 1200 District 

Avenue, 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 by adding an AD that would 

apply to all Pratt & Whitney Division 

(PW) PW4052, PW4056, PW4060, 

PW4062, PW4062A, PW4152, 

PW4156A, PW4158, PW4460, and 

PW4462 turbofan engine models, 

including engines identified with 

suffixes –1C, –1E, –3, –3A, or –3B. The 

NPRM published in the Federal 

Register on October 12, 2017 (82 FR 

47405). The NPRM was prompted by the 

discovery of multiple cracked 4th stage 

LPT air seals, part number (P/N) 

50N346, in the fleet. An investigation 

determined there is insufficient 

clearance to the 4th stage LPT vane 

cluster honeycomb that makes up the 

other half of the sealing system. Also, 

the knife edge seals are uncoated so they 

are more susceptible to overheating if a 

hard rub with the honeycomb occurs. 

The NPRM proposed to require the 

removal from service of certain 4th stage 

LPT air seals. Replacement of the air 

seal also requires replacement of the 4th 

stage LPT vane cluster honeycomb. This 

condition, if not corrected, could result 

in failure of the air seal, uncontained air 

seal release, damage to the engine, and 

damage to the airplane. We are issuing 

this AD to address the unsafe condition 

on these products. 

Comments 

We gave the public the opportunity to 

participate in developing this final rule. 

The following presents the comments 

received on the NPRM and the FAA’s 

response to each comment. 

Request To Clarify Compliance Time 

United Parcel Service, United 

Airlines, SR Technics, Delta Airlines 

(DAL), Atlas Air, Federal Express 

(FedEx), and the Boeing Company 

requested that we clarify the compliance 

time requirement specified in the 

NPRM, paragraph (f)(1), which stated 

‘‘at the next disassembly of the LPT 

module, remove 4th stage air seal, P/N 

50N346, from service and replace with 

a part eligible for installation’’ because 

the term ‘‘disassembly’’ is subjective 

and not defined elsewhere in the NPRM. 

DAL requested that we specify a 

compliance time in the final rule since 

paragraph (f)(1) of the NPRM indicates 

that the compliance actions should be 

done in accordance with the compliance 

times specified in the AD. 

We agree. We clarified that the 

compliance in this AD should be 

performed ‘‘the next time the 4th stage 

LPT vanes are removed from the LPT 

module.’’ 

Request for Clarification on Installation 

Prohibition 

DAL requested clarification on the 

acceptability of returning an LPT to 

service with P/N 50N346 installed if the 

air seal was not exposed at the piecepart level, because the LPT disassembly 

was limited. 

An LPT module with a 4th stage air 

seal, P/N 50N346, installed, may be 

returned to service, if the 4th stage LPT 

vanes are not removed. However, 

replacement of the 4th stage air seal is 

required, when the 4th stage LPT vanes 

are removed. This would include, if the 

4th stage LPT air seal was at the piecepart exposure level. 

Request for Clarification on 

Replacement of Affected Air Seals 

Cathay Pacific Airways (CPA) asked if 

replacing the 4th stage LPT air seal, P/ 

N 50N346, with any of the other 4th 

stage LPT air seals depicted in the 

Illustrated Parts Catalog (IPC) fulfills the 

AD requirement or if P/N 51N113 is the 

only suitable air seal for replacement. 

CPA further requested that we define 

what is ‘‘a part eligible for installation’’ 


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27890 Federal Register / Vol. 83, No. 116 / Friday, June 15, 2018 / Rules and Regulations 

in paragraph (f)(1) of the NPRM which 

states ‘‘at the next disassembly of the 

LPT module, remove 4th stage air seal, 

P/N 50N346, from service and replace 

with a part eligible for installation.’’ 

Currently, P/N 51N113 is the only 4th 

stage LPT air seal suitable for P/N 

50N346 replacement. However, new 

replacement air seals may be developed 

in the future. We did not change this 

AD. 

Service Bulletin Comment 

CPA stated that PW Service Bulletin 

(SB) PW4ENG A72–830, Revision No. 1, 

dated May 2, 2017, listed P/N 51N113 

as the only part eligible for installation. 

However, the service bulletin is not 

clearly listed in paragraph (f) of the 

NPRM. 

We disagree. We listed PW SB 

PW4ENG A72–830, Revision No. 1, 

dated May 2, 2017, in the ‘‘Related 

Service Information’’ section of the 

NPRM, which was the appropriate 

paragraph. We did not change this AD. 

Request for Clarification on 

Applicability of AD 

Atlas Air asked if the AD applies to 

engines with 4th stage LPT air seals, P/ 

N 51N038, 50N478, or 50N478–001, 

installed. 

We determined this AD only applies 

to engines with 4th stage LPT air seal, 

P/N 50N346, installed. 

Request for Clarification on Repair 

Limits 

Atlas Air asked if PW Clean, Inspect, 

Repair (CIR) 72–53–40 Inspection/ 

Check-03 limits apply to the 4th stage 

LPT air seal, P/N 51N113. If so, Atlas 

Air is concerned that the reduced knife 

edge might get scrapped due to reduced 

diameters. 

The intent of this AD is to install a 4th 

stage LPT air seal with reduced knife 

edge diameters. This AD does not 

impact the CIR 72–53–40 Inspection/ 

Check-03 limits. 

Request for Clarification on ReInstallation Prohibition 

Atlas Air asked if 4th stage LPT air 

seals, P/N 51N038, 50N478, or 50N478– 

001 are prohibited from re-installation. 

We determined that 4th stage LPT air 

seals, P/N 51N038, 50N478, and 

50N478–001, are not applicable to the 

engines affected by this AD. 

Request for Clarification on Effective 

Date 

SR Technics asked when this AD will 

become effective. 

This AD will be effective 35 days after 

publication in the Federal Register. 

Request for Clarification on Part 

Modification 

PW stated that the new part can be 

obtained by modification of the old part 

as specified in PW SB PW4ENG A72– 

830, Revision No. 1, dated May 2, 2017. 

We agree. The new 4th stage LPT air 

seal, P/N 51N113, can be obtained 

through modification of the old air seal, 

P/N 50N346, as noted in PW SB 

PW4ENG A72–830, Revision No. 1, 

dated May 2, 2017. 

Request for Clarification on Honeycomb 

Replacement 

DAL and FedEx note that the NPRM 

states ‘‘Replacement of the air seal also 

requires replacement of the 4th stage 

LPT vane cluster honeycomb’’ in the 

‘‘Discussion’’ paragraph. However, 

paragraph (f) in the NPRM does not 

address honeycomb replacement. The 

commenters asked if the FAA intends to 

require the replacement of the 

honeycomb. 

This AD addresses the unsafe 

condition created by a cracked 4th stage 

LPT air seal by replacing the air seal 

with a part that does not crack. 

Installation of the new air seal without 

replacement of the 4th stage LPT vane 

cluster honeycomb results in an 

increased radial clearance between the 

honeycomb and air seals. This is not an 

approved configuration. Requirements 

for replacement of the honeycomb when 

an air seal is replaced are defined in the 

appropriate service information, such as 

PW CIR Manual P/N 51A357, Chapter/ 

Section 72–53–24, Repair-02. We did 

not change this AD. 

Supportive Comment 

The Air Line Pilots Association 

International expressed support for this 

AD. 

Conclusion 

We reviewed the relevant data, 

considered the comments received, and 

determined that air safety and the 

public interest require adopting this 

final rule with the changes described 

previously and for minor editorial 

changes. We have determined that these 

minor changes: 

• Are consistent with the intent that 

was proposed in the NPRM for 

addressing the unsafe condition; and 

• Do not add any additional burden 

upon the public than was already 

proposed in the NPRM. 

We also determined that these 

changes will not increase the economic 

burden on any operator or increase the 

scope of this final rule. 

Related Service Information 

We reviewed PW SB PW4ENG A72– 

830, Revision No. 1, dated May 02, 

2017. The SB describes procedures for 

replacement or modification of the 4th 

stage LPT air seals. 

Costs of Compliance 

We estimate that this AD affects 991 

engines installed on aircraft of U.S. 

registry. 

We estimate the following costs to 

comply with this AD: 

ESTIMATED COSTS

Action Labor cost Parts cost Cost per 

product 

Cost on U.S. 

operators 

Replacement of air seal .................................. 0 work-hours × $85 per hour = $0 ................. $13,800 $13,800 $13,675,800 

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. 

This AD is issued in accordance with 

authority delegated by the Executive 

Director, Aircraft Certification Service, 

as authorized by FAA Order 8000.51C. 

In accordance with that order, issuance 


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Federal Register / Vol. 83, No. 116 / Friday, June 15, 2018 / Rules and Regulations 27891 

of ADs is normally a function of the 

Compliance and Airworthiness 

Division, but during this transition 

period, the Executive Director has 

delegated the authority to issue ADs 

applicable to engines, propellers, and 

associated appliances to the Manager, 

Engine and Propeller Standards Branch, 

Policy and Innovation Division. 

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—AIRWORTHINESS 

DIRECTIVES 

■ 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 adding 

the following new airworthiness 

directive (AD): 

2018–13–02 Pratt & Whitney Division: 

Amendment 39–19314; Docket No. 

FAA–2017–0817; Product Identifier 

2017–NE–30–AD. 

(a) Effective Date 

This AD is effective July 20, 2018. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to all Pratt & Whitney 

Division (PW) PW4052, PW4056, PW4060, 

PW4062, PW4062A, PW4152, PW4156A, 

PW4158, PW4460, and PW4462 turbofan 

engine models, including engines identified 

with suffixes –1C, –1E, –3, –3A, or –3B, with 

4th stage low-pressure turbine (LPT) air seal, 

part number (P/N) 50N346, installed. 

(d) Subject 

Joint Aircraft System Component (JASC) 

Code 7240, Turbine Engine Combustion 

Section. 

(e) Unsafe Condition 

This AD was prompted by the discovery of 

multiple cracked air seals. We are issuing 

this AD to prevent failure of the 4th stage 

LPT air seal. This unsafe condition, if not 

addressed, could result in uncontained 

release of the air seal, damage to the engine, 

and damage to the airplane. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Required Actions 

The next time the 4th stage LPT vanes are 

removed from the LPT module, remove 4th 

stage air seal, P/N 50N346, from service and 

replace with a part eligible for installation. 

(h) Installation Prohibition 

After the effective date of this AD, do not 

install any 4th stage LPT air seal, P/N 

50N346, into any LPT module. 

(i) Alternative Methods of Compliance 

(AMOCs) 

(1) The Manager, ECO Branch, FAA, has 

the authority to approve AMOCs for this AD, 

if requested using the procedures found in 14 

CFR 39.19. In accordance with 14 CFR 39.19, 

send your request to your principal inspector 

or local flight standards district office, as 

appropriate. If sending information directly 

to the manager of the certification office, 

send it to the attention of the person 

identified in paragraph (j) of this AD. You 

may email your request to: ANE-AD-AMOC@

faa.gov. 

(2) Before using any approved AMOC, 

notify your appropriate principal inspector, 

or lacking a principal inspector, the manager 

of the local flight standards district office/ 

certificate holding district office. 

(j) Related Information 

For more information about this AD, 

contact Jo-Ann Theriault, Aerospace 

Engineer, ECO Branch, FAA, 1200 District 

Avenue, Burlington, MA 01803; phone: 781– 

238–7105; fax: 781–238–7199; email: joann.theriault@faa.gov. 

(k) Material Incorporated by Reference 

None. 

Issued in Burlington, Massachusetts, on 

June 11, 2018. 

Robert J. Ganley, 

Manager, Engine and Propeller Standards 

Branch, Aircraft Certification Service. 

[FR Doc. 2018–12830 Filed 6–14–18; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2018–0501; Product 

Identifier 2018–NE–19–AD; Amendment 39– 

19304; AD 2018–11–16] 

RIN 2120–AA64 

Airworthiness Directives; Engine 

Alliance Turbofan Engines 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule; request for 

comments. 

SUMMARY: We are adopting a new 

airworthiness directive (AD) for certain 

Engine Alliance (EA) GP7270, GP7272, 

and GP7277 turbofan engines. This AD 

requires a one-time eddy current 

inspection (ECI) of the engine fan hub 

blade slot bottom and blade slot front 

edge for cracks, a visual inspection of 

the engine fan hub for damage, and 

removal of parts if damage or defects are 

found that are outside serviceable 

limits. This AD was prompted by an 

uncontained failure of the engine fan 

hub. We are issuing this AD to address 

the unsafe condition on these products. 

DATES: This AD is effective July 2, 2018. 

The Director of the Federal Register 

approved the incorporation by reference 

of a certain publication listed in this AD 

as of July 2, 2018. 

We must receive comments on this 

AD by July 30, 2018. 

ADDRESSES: You may send comments, 

using the procedures found in 14 CFR 

11.43 and 11.45, by any of the following 

methods: 

• Federal eRulemaking Portal: Go to 

http://www.regulations.gov. Follow the 

instructions for submitting comments. 

• Fax: 202–493–2251. 

• Mail: U.S. Department of 

Transportation, Docket Operations, M– 

30, West Building Ground Floor, Room 

W12–140, 1200 New Jersey Avenue SE, 

Washington, DC 20590. 

• Hand Delivery: U.S. Department of 

Transportation, Docket Operations, M– 

30, West Building Ground Floor, Room 

W12–140, 1200 New Jersey Avenue SE, 

Washington, DC 20590, between 9 a.m. 

and 5 p.m., Monday through Friday, 

except Federal holidays. 

For service information identified in 

this final rule, contact Engine Alliance, 

411 Silver Lane, East Hartford, CT 

06118; phone: 800–565–0140; email: 

help24@pw.utc.com; website: 

www.engineallianceportal.com. You 

may view this service information at the 

FAA, Engine and Propeller Standards 


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