
[Federal Register Volume 82, Number 66 (Friday, April 7, 2017)]
[Rules and Regulations]
[Pages 16897-16898]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-06708]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-7095; Directorate Identifier 2015-SW-085-AD; 
Amendment 39-18848; AD 2017-07-09]
RIN 2120-AA64


Airworthiness Directives; Sikorsky Aircraft Corporation 
Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for 
Sikorsky Aircraft Corporation (Sikorsky) Model S-92A helicopters. This 
AD requires removing from service the tail gearbox center housing 
(housing) when it has 12,200 or more hours time-in-service (TIS). This 
AD was prompted by fatigue analysis conducted by Sikorsky that 
determined the housing required a retirement life. The actions are 
intended to prevent an unsafe condition on these products.

DATES: This AD is effective May 12, 2017.

ADDRESSES: For service information identified in this final rule, 
contact Sikorsky Aircraft Corporation, Customer Service Engineering, 
124 Quarry Road, Trumbull, CT 06611; telephone 1-800-Winged-S or 203-
416-4299; email: wcs_cust_service_eng.gr-sik@lmco.com. You may review a 
copy of the referenced service information at the FAA, Office of the 
Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, 
Fort Worth, TX 76177.

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-
7095; or in person at the Docket Operations Office between 9 a.m. and 5 
p.m., Monday through Friday, except Federal holidays. The AD docket 
contains this AD, the economic evaluation, any comments received, and 
other information. The street address for the Docket Operations Office 
(phone: 800-647-5527) is U.S. Department of Transportation, Docket 
Operations Office, M-30, West Building Ground Floor, Room W12-140, 1200 
New Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Kristopher Greer, Aerospace Engineer, 
Boston Aircraft Certification Office, Engine & Propeller Directorate, 
FAA, 1200 District Avenue, Burlington, Massachusetts 01803; telephone 
781-238-7799; email Kristopher.Greer@faa.gov.

SUPPLEMENTARY INFORMATION: 

Discussion

    On August 30, 2016, at 81 FR 59526, the Federal Register published 
our notice of proposed rulemaking (NPRM), which proposed to amend 14 
CFR part 39 by adding an AD that would apply to Sikorsky Model S-92A 
helicopters with a housing part number (P/N) 92358-06107-043 installed. 
The NPRM proposed to require removing from service any housing with 
12,200 or more hours TIS. The NPRM was prompted by fatigue analysis 
conducted by Sikorsky that determined the housing required a retirement 
life. The proposed actions were intended to prevent a crack in the 
housing, which could lead to loss of tail rotor drive and loss of 
helicopter control.

Comments

    After our NPRM was published, we received a comment from Sikorsky.

Request

    Sikorsky requested a minimum 45-day extension of the comment 
period. In support of this request, Sikorsky stated it is re-evaluating 
the housing's 12,200-hour life limit due to an error in the measured 
flight test loads used in the structural fatigue substantiation. When 
asked for additional information, Sikorsky advised that it had 
completed its re-evaluation and determined that the 12,200-hour life 
limit was, in fact, correct.

FAA's Determination

    We have reviewed the relevant information and determined that an 
unsafe condition exists and is likely to exist or develop on other 
products of

[[Page 16898]]

these same type designs and that air safety and the public interest 
require adopting the AD requirements as proposed.

Related Service Information

    We reviewed Sikorsky S-92 Maintenance Manual 4-00-00, Temporary 
Revision No. 4-49, dated April 10, 2015, which establishes a 
replacement interval of 12,200 hours for housing, P/N 92358-06107-043.

Costs of Compliance

    We estimate that this AD affects 80 helicopters of U.S. Registry 
and that labor costs average $85 per work hour. Based on these 
estimates, we expect the following costs.
    Replacing the housing requires 24 work-hours, and parts cost 
$58,000 for a total cost of $60,040 per helicopter.

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

    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.
    We prepared an economic evaluation of the estimated costs to comply 
with this AD and placed it in the AD docket.

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

0
1. The authority citation for part 39 continues to read as follows:

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


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2017-07-09 Sikorsky Aircraft Corporation: Amendment 39-18848; Docket 
No. FAA-2015-7095; Directorate Identifier 2015-SW-085-AD.

(a) Applicability

    This AD applies to Sikorsky Aircraft Corporation (Sikorsky) 
Model S-92A helicopters, certificated in any category, with a tail 
gearbox center housing, part number (P/N) 92358-06107-043, 
installed.

(b) Unsafe Condition

    This AD defines the unsafe condition as a crack in a tail 
gearbox center housing. This condition could result in failure of 
the tail rotor drive and consequently loss of helicopter control.

(c) Effective Date

    This AD becomes effective May 12, 2017.

(d) Compliance

    You are responsible for performing each action required by this 
AD within the specified compliance time unless it has already been 
accomplished prior to that time.

(e) Required Actions

    Before further flight, remove from service any tail gearbox 
housing, P/N 92358-06107-043, that has 12,200 or more hours time-in-
service.

(f) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Boston Aircraft Certification Office, FAA, may 
approve AMOCs for this AD. Send your proposal to: Kristopher Greer, 
aerospace engineer, Boston Aircraft Certification Office, Engine & 
Propeller Directorate, FAA, 1200 District Avenue, Burlington, 
Massachusetts 01803; telephone 781-238-7799; email 
Kristopher.Greer@faa.gov.
    (2) For operations conducted under a 14 CFR part 119 operating 
certificate or under 14 CFR part 91, subpart K, we suggest that you 
notify your principal inspector, or lacking a principal inspector, 
the manager of the local flight standards district office or 
certificate holding district office before operating any aircraft 
complying with this AD through an AMOC.

(g) Additional Information

    Sikorsky S-92 Maintenance Manual 4-00-00, Temporary Revision No. 
4-49, dated April 10, 2015, which is not incorporated by reference, 
contains additional information about the subject of this AD. For 
service information identified in this AD, contact Sikorsky Aircraft 
Corporation, Customer Service Engineering, 124 Quarry Road, 
Trumbull, CT 06611; telephone 1-800-Winged-S or 203-416-4299; email: 
wcs_cust_service_eng.gr-sik@lmco.com. You may review a copy of this 
service information at the FAA, Office of the Regional Counsel, 
Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, Fort Worth, TX 
76177.

(h) Subject

    Joint Aircraft Service Component (JASC) Code: 6520, Tail Rotor 
Gearbox.

    Issued in Fort Worth, Texas, on March 29, 2017.
Scott A. Horn,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2017-06708 Filed 4-6-17; 8:45 am]
BILLING CODE 4910-13-P


