AD 2017-07-09
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sikorsky Aircraft Corporation | S-92A | Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters |
Unsafe Condition
A crack in the tail gearbox center housing, which could result in failure of the tail rotor drive and consequently loss of helicopter control.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Remove from service any tail gearbox center housing, part number 92358-06107-043, that has 12,200 or more hours time-in-service before further flight.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Before further flight
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Sikorsky Aircraft Corporation Model S-92A helicopters with a tail gearbox center housing, part number 92358-06107-043, installed.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
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.
Document Text
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[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 [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[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: <a href="/cdn-cgi/l/email-protection#2e594d5d714d5b5d5a715d4b5c58474d4b714b404900495c035d47456e42434d41004d4143"><span class="__cf_email__" data-cfemail="bdcadecee2dec8cec9e2ced8cfcbd4ded8e2d8d3da93dacf90ced4d6fdd1d0ded293ded2d0">[email protected]</span></a>. 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 <a href="http://www.regulations.gov">http://www.regulations.gov</a> 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 <a href="/cdn-cgi/l/email-protection#511a233822253e213934237f1623343423113730307f363e27"><span class="__cf_email__" data-cfemail="5d162f342e29322d35382f731a2f38382f1d3b3c3c733a322b">[email protected]</span></a>.
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
<a href="/cdn-cgi/l/email-protection#5b102932282f342b333e29751c293e3e291b3d3a3a753c342d"><span class="__cf_email__" data-cfemail="a3e8d1cad0d7ccd3cbc6d18de4d1c6c6d1e3c5c2c28dc4ccd5">[email protected]</span></a>.
(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:
<a href="/cdn-cgi/l/email-protection#e99e8a9ab68a9c9a9db69a8c9b9f808a8cb68c878ec78e9bc49a8082a985848a86c78a8684"><span class="__cf_email__" data-cfemail="b8cfdbcbe7dbcdcbcce7cbddcaced1dbdde7ddd6df96dfca95cbd1d3f8d4d5dbd796dbd7d5">[email protected]</span></a>. 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
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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