[Docket No. FAA-2015-3661; Directorate Identifier 2015-NE-24-AD; Amendment 

39-18422; AD 2016-05-04[ 

RIN 2120-AA64 

Airworthiness Directives; Dowty Propellers Constant Speed Propellers 

AGENCY: Federal Aviation Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: We are adopting a new airworthiness directive (AD) for certain Dowty 

Propellers R352/6-123-F/l, R352/6-123-F/2, and R410/6-123-F/35 model propellers. 

This AD was prompted by reports of dowel hole cracks in the face of the rear hub half. 

This AD requires installing dowel hole liners as necessary. We are issuing this AD to 

prevent loss of structural integrity of the propeller hub, which could result in damage to 

the propeller and damage to the airplane. 

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

PUBLICATION IN THE FEDERAL REGISTER]. 

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

certain publication listed in this AD as of [INSERT DATE 35 DAYS AFTER DATE OF 

PUBLICATION IN THE FEDERAL REGISTER]. 

ADDRESSES: For service information identified in this final rule, contact Do\Vty 

Propellers, 114 Powers Court, Sterling, VA 20166; phone: 703-421-4434; fax: 703-450-
Internet at http://www.regulations.gov by searching for and locating Docket No. FAA2015-3661. 

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-2015-3661; 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 mandatory continuing airworthiness 

information (MCAI), 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 W12-140, 1200 New Jersey Avenue SE., 

Washington, DC 20590. 

FOR FURTHER INFORMATION CONTACT: Michael Schwetz, Aerospace 

Engineer, Boston Aircraft Certification Office, FAA, Engine & Propeller Directorate, 

1200 District Avenue, Burlington, MA 01803; phone: 781-238-7761; fax: 781-238-7898; 

email: michael.schwetz@faa.gov. 

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the Federal Register on October 13, 2015 (80 FR 61330). The NPRM proposed to correct 

an unsafe condition for the specified products. The MCAI states: 

Cracking around the hub location dowel holes in the face of the 

rear hub half has occurred sporadically. Previous investigations 

found no manufacturing defects in cracked hubs and concluded 

that the hub cracking was caused by damage to the dowel holes 

during propeller installation. 

Since that original SB was issued, three hubs have been found to 

show cracking around the location dowel holes. The hubs were all 

found cracked within a short period of time and all had low time 

since new. 

This condition, if not detected, can adversely affect the structural 

integrity of the propeller hub, with possible damage to the 

propeller and to the aeroplane. 

You may obtain further information by examining the MCAI in the AD docket on 

the Internet at http://www.regulations.gov by searching for and locating Docket No. 

FAA-2015-3661. 

Comments 

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

received no comments on the NPRM (80 FR 61330, October 13, 2015). 

However, we changed paragraph (e) Actions and Compliance to revise the 

compliance times to read, "(1) At the next removal of the propeller from the airplane, 

after the effective date of this AD, install liners into the hub location dowel holes and 

identify the hub PIN. 

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We removed Component Maintenance Manual (CMM) 61-10-34, Repair No. 53, 

dated May 15, 2013, which relates to repair scheme 650510057, from the Credit for 

Previous Actions paragraph (1)(2) of this AD. 

We removed CMM 61-10-34, Repair No. 53, dated May 15,2013, from the 

Related Information paragraph (h) of this AD. 

Conclusion 

We reviewed the available data and determined that air safety and the public 

interest require adopting this AD with the changes described previously. We determined 

that these changes will not increase the economic burden on any operator or increase the 

scope of this AD. 

Related Service Information under 1 CFR Part 51 

Dowty Propellers has issued (ASB) No. F50-61-Al65, Revision 2, dated July 28, 

2015. The service information describes procedures for installing liners in the hub 

location dowel holes in the face of the rear hub half and identifying the hub with the 

repair number. This service information is reasonably available because the interested 

parties have access to it through their nonnal course of business or by the means 

identified in the ADDRESSES section of this final rule. 

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Based on these figures, we estimate the cost of this AD on U.S. operators to be $2,988. 

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 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 this AD: 

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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. 

Adoption of the Amendment 

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

amends 14 CPR 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): 

2016-05-04 Dowty Propellers: Amendment 39-18422; Docket No. F AA-2015-3661; 

Directorate Identifier 2015-NE-24-AD. 

(a) Effective Date 

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

PUBLICATION IN THE FEDERAL REGISTER]. 

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R410/6-123-F/35 model propellers, part numbers (PINs) 660715001,660715004, and 

660715005 with hub PINs 660715201, 660715255, 660720217, 660720241, 660720252, 

660720260, and 660720288, installed. 

(d) Reason 

This AD was prompted by reports of dowel hole cracks in the face of the rear hub 

half. We are issuing this AD to prevent loss of structural integrity of the propeller hub, 

which could result in damage to the propeller and damage to the airplane. 

(e) Actions and Compliance 

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

(1) At the next removal of the propeller from the airplane, after the effective date 

of this AD, installlin~rs into the hub location dowel holes and identify the hub PIN. 

(2) Use Dowty Propellers Alert Service Bulletin (ASB) No. F50-61-Al65, 

Revision 2, dated July 28, 2015 to install the liners and identify the hub. 

(f) Credit for Previous Actions 

You may take credit for the actions required by paragraph (e) of this AD if you 

performed those actions before the effective date of this AD using Dowty Propellers ASB 

No. F50-61-A165, Revision 1, dated May 12, 2015; or initial issue, dated November 19, 

2012. 

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(I) For more information about this AD, contact Michael Schwetz, Aerospace 

Engineer, Boston Aircraft Certification Office, FAA, 1200 District Avenue, Burlington, 

MA 01803; phone: 781-238-7761; fax: 781-238-7898; email: michael.schwetz@faa.gov. 

(2) Refer to MCAI European Aviation Safety Agency AD 2015-0158, dated July 

30, 2015, for more information. You may examine the MCAI in the AD docket on the 

Internet at http://wwv.i.regulations.gov by searching for and locating it in Docket No. 

FAA-2015-3661. 

(i) Material Incorporated by Reference 

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

(IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 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. 

(i) Dowty Propellers Alert Service Bulletin No. F50-61-Al65, Revision 2, dated 

July 28, 2015. 

(ii) Reserved. 

(3) For Dowty Propellers service information identified in this AD, contact Dowty 

Propellers, 114 Powers Court, Sterling, VA 20166; phone: 703-421-4434; fax: 703-450-

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this material at the FAA, call781-238-7125. 

(5) You may view this service information at the National Archives and Records 

Administration (NARA). For information on the availability of this material at NARA, 

call202-741-6030, or go to: http://wwvv.archives.gov/federal-register/cfr/ibrlocations.html. 

n, Massachusetts, on February 24, 2016. 

Robert J. Ganley, 

Acting Manager, Engine & Propeller Directorate, 

Aircraft Certification Service. 

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