DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA-2015-4866; Directorate Identifier 2015-NE-33-AD[ 

RIN 2120-AA64 

[4910-13-P[ 

Airworthiness Directives; Honeywell International Inc. Turboprop and Turboshaft 

Engines 

AGENCY: Federal Aviation Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking (NPRM). 

SUMMARY: We propose to adopt a new airworthiness directive (AD) for certain 

Honeywell International Inc. (Honeywell) TPE331 model turboprop engines and 

TSE331-3U model turboshaft engines. This proposed AD was prompted by the discovery 

of cracks in a 2nd stage compressor impeller during a routine shop visit. This proposed 

AD would require removal of the 2nd stage compressor impeller. We are proposing this 

AD to prevent failure of the compressor impeller, uncontained part release, damage to the 

engine, and damage to the airplane. 

DATES: We must receive comments on this proposed AD by [INSERT DATE 60 

DAYS AFTER DATE OF PUBLICATION IN THE Federal Register]. 

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: Deliver to Mail address above between 9 a.m. and 5 p.m., 

Monday through Friday, except Federal holidays. 

Examining the AD Docket 

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

searching for and locating Docket No. F AA-2015-4866; 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 proposed AD, the regulatory evaluation, any 

comments received, and other information. The street address for the Docket Office 

(phone: 800-647-5527) is in the ADDRESSES section. Comments will be available in the 

AD docket shortly after receipt. 

FOR FURTHER INFORMATION CONTACT: Joseph Costa, Aerospace Engineer, 

Los Angeles Aircraft Certification Office, FAA, Transport Airplane Directorate, 3960 

Paramount Blvd,, Lakewood, CA 90712-4137; phone: 562-627-5246; fax: 562-627-5210; 

email: joseph.costa@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

We invite you to send any written relevant data, views, or arguments about this 

NPRM. Send your conunents to an address listed under the ADDRESSES section. 

Include "Docket No. F AA-2015-4866; Directorate Identifier 2015-NE-33-AD" at the 

beginning of your conunents. We specifically invite comments on the overall regulatory, 

economic, environmental, and energy aspects of this NPRM. We will consider all 

comments received by the closing date and may amend this NPRM because 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 

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also post a report summarizing each substantive verbal contact we receive about this 

NPRM. 

Discussion 

Several 2nd stage compressor impellers were found cracked in the aft curvic root 

radius when inspected during a routine shop visit. This condition, if not corrected, could 

result in failure of the compressor impeller, uncontained part release, damage to the 

engine, and damage to the airplane. 

FAA's Determination 

We are proposing this NPRM because we evaluated all the relevant information 

and determined the unsafe condition described previously is likely to exist or develop in 

other products of the same type design. 

Proposed AD Requirements 

This NPRM would require accomplishing the actions specified in the service 

information described previously. 

Costs of Compliance 

We estimate that this proposed AD would affect 4,000 engines installed on 

airplanes of U.S. registry. We estimate that it would take 0 hours per engine to comply 

with this proposed AD. The average labor rate is $85 per hour. We also estimate that 

required parts would cost about $1,513.25 per engine. Based on these figures, we 

estimate the total cost of this proposed AD on U.S. operators to be $6,053,000. 

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. 

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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 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 this proposed regulation: 

(1) Is not a "significant regulatory action" under Executive Order 12866, 

(2) Is not a "significant rule" m1der the 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 m1der the criteria of the Regulatory Flexibility Act. 

List of Subjects in 14 CFR Part 39 

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. 

The Proposed Amendment 

Accordingly, tmder the authority delegated to me by the Administrator, the FAA 

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: 

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): 

Honeywell International Inc. (Type Certificate previously held by AlliedSignal Inc., 

Garrett Engine Division; Garrett Turbine Engine Company; and AiResearch 

Manufacturing Company of Arizona): Docket No. FAA-2015-4866; Directorate 

Identifier 2015-NE-33-AD. 

(a) Comments Due Date 

We must receive comments by [INSERT DATE 60 DAYS AFTER DATE OF 

PUBLICATION IN THE Federal Register]. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to Honeywell International Inc. (Honeywell) TPE331-3U, -3UW, 

-5, -SA, -SAB, -SB, -6, -6A, -8,-10, -lOAV, -lOGP, -lOGT, -!ON, -lOP, -lOR, -lOT, 

-lOU, -lOUA, -lOUF, -lOUG, -lOUGR, -lOUR, and -llU model turboprop engines, and 

TSE331-3U model turboshaft engines, with a 2nd stage compressor impeller, part number 

(PIN) 893482-1 through -5, inclusive, or PIN 31 07056-l or PIN 3107056-2, installed. 

(d) Unsafe Condition 

This AD was prompted by the discovery of cracks in a 2nd stage compressor 

impeller during a routine shop visit. We are issuing this AD to prevent failure of the 

compressor impeller, uncontained part release, damage to the engine, and damage to the 

airplane. 

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(e) Compliance 

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

(1) Remove fTom service the 2nd stage compressor impeller within 200 cycles-inservice after the effective date of the AD, or before exceeding 7,000 cycles since last 

overhaul, whichever occurs later. 

(t) Installation Prohibition 

After the effective date of this AD, do not install a 2nd stage compressor impeller, 

part number (PIN) 893482-1 through -5, inclusive, or PIN 3107056-1 or PIN 3107056-2 

into any engine. 

(g) Alternative Methods of Compliance (AMOCs) 

The Manager, Los Angeles Aircraft Certification Office, FAA, may approve 

AMOCs for this AD. Use the procedures fmmd in 14 CFR 39.19 to make your request. 

(h) Related Information 

(1) For more information about this AD, contact Joseph Costa, Aerospace 

Engineer, Los Angeles Aircraft Certification Office, FAA, Transport Airplane 

Directorate, 3960 Paramount Blvd., Lakewood, CA 90712-4137; phone: 562-627-5246; 

fax: 562-627-521 0; email: joseph.costa@faa.gov. 

Issued in Burlington, Massachusetts, on March 4, 2016. 

Colleen M. D' Alessandro, 

Manager, Engine & Propeller Directorate, 

Aircraft Certification Service. 

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