[Federal Register Volume 75, Number 221 (Wednesday, November 17, 2010)]
[Rules and Regulations]
[Pages 70101-70102]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-28458]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2010-0490; Directorate Identifier 2010-SW-037-AD;
Amendment 39-16514; AD 2010-23-24]
RIN 2120-AA64
Airworthiness Directives; Sikorsky Aircraft Corporation
(Sikorsky) Model S-70A and S-70C Helicopters
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD) for
the Sikorsky Model S-70A and S-70C helicopters. This AD requires an
ultrasonic test (UT) inspection of the tail gearbox output bevel gear
(gear) for a crack. If you find a crack, replacing the gear with an
airworthy gear is required before further flight. This AD is prompted
by three gear cracking incidents, one of which resulted in the tail
rotor separating from the helicopter. The actions specified by this AD
are intended to detect a crack in the gear to prevent a tail rotor
separating, loss of tail rotor control, and subsequent loss of control
of the helicopter.
DATES: Effective December 22, 2010.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of December 22, 2010.
ADDRESSES: You may get the service information identified in this AD
from Sikorsky Aircraft Corporation, Attn: Manager, Commercial Technical
Support, mailstop s581a, 6900 Main Street, Stratford, CT, telephone
(203) 383-4866, e-mail address [email protected], or at http://www.sikorsky.com.
Examining the Docket: You may examine the docket that contains this
AD, any comments, and other information on the Internet at http://www.regulations.gov or at the Docket Operations office, West Building
Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington,
DC.
FOR FURTHER INFORMATION CONTACT: Michael Schwetz, Aviation Safety
Engineer, Boston Aircraft Certification Office, 12 New England
Executive Park, Burlington, MA 01803, telephone (781) 238-7761, fax
(781) 238-7170.
SUPPLEMENTARY INFORMATION: A proposal to amend 14 CFR part 39 to
include an AD for the specified model helicopters was published in the
Federal Register on May 13, 2010 (75 FR 26888). That action proposed to
require a UT inspection of the gear for a crack and replacing any
cracked gear before further flight. The proposal was prompted by three
gear crack incidents, one of which resulted in the tail rotor
separating from the helicopter. The tail gearbox on the helicopter
where the tail rotor separated from the helicopter experienced a
fracture of the output shaft spline that drives the tail rotor blades.
An investigation into the cause of the cracks is ongoing. The unsafe
condition described previously, if not corrected, could result in a
tail rotor separating, loss of tail rotor control, and subsequent loss
of control of the helicopter.
We have reviewed Sikorsky Alert Service Bulletin No. 70-06-28A,
Revision A, dated May 21, 2009 (ASB), which refers to procedures for a
UT inspection of the gear in accordance with Special Service
Instructions (SSI) No. 70-121A or latest revision.
This unsafe condition is likely to exist or develop on other
helicopters of the same type design. Therefore, this AD requires a UT
inspection of the gear, part number 70358-06620, for a crack. If a
crack is found, this AD requires replacing the gear with an airworthy
gear before further flight. The actions are required to be to be done
by following the SSI described previously.
We provided the public the opportunity to participate in developing
this AD. We received no comments on the proposal or on the
determination of the cost to the public. Therefore, we are adopting the
action as proposed with only minor non-substantive changes.
We estimate that this AD affects 5 helicopters in the U.S.
registry. The actions will take about 4 work hours per helicopter at an
average labor rate of $85 per work hour. Required parts cost about
$20,000 for each gear. Based on these figures, we estimate the total
cost impact of this AD on U.S. operators to be $101,700, assuming the
gear is replaced on the entire fleet.
Regulatory Findings
We have 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 that the regulation:
1. Is not a ``significant regulatory action'' under Executive Order
12866;
2. Is not a ``significant rule'' under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979); and
3. 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. See the AD docket to examine the economic evaluation.
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 AD.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
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Accordingly, under the authority delegated to me by the Administrator,
the Federal Aviation Administration amends part 39 of the Federal
Aviation Regulations (14 CFR part 39) as follows:
[[Page 70102]]
PART 39--AIRWORTHINESS DIRECTIVES
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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]
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2. FAA amends Sec. 39.13 by adding the following new AD:
2010-23-24 Sikorsky Aircraft Corp.: Amendment 39-16514; Docket No.
FAA-2010-0490; Directorate Identifier 2010-SW-037-AD.
Applicability: Model S-70A and S-70C helicopters with a tail
gearbox output bevel gear (gear), part number 70358-06620,
certificated in any category.
Compliance: Required as indicated.
To prevent a tail rotor separating, loss of tail rotor control,
and subsequent loss of control of the helicopter, do the following:
(a) Within 500 hours time-in-service (TIS), unless accomplished
previously, and thereafter at intervals not to exceed 500 hours TIS,
remove the tail rotor servo control and pitch beam shaft, and using
a Level II Ultrasonic Testing Technician or equivalent, ultransonic
inspect the gear for a crack. Ultrasonic inspect the gear by
following paragraphs A.(5)a. through A(5)n. of Special Service
Instructions No. 70-121A, Revision A, dated May 21, 2009. If you
find a crack, before further flight, replace the gear with an
airworthy gear.
(b) To request a different method of compliance or a different
compliance time for this AD, follow the procedures in 14 CFR 39.19.
Contact the Manager, Boston Aircraft Certification Office, FAA,
Attn: Michael Schwetz, Aviation Safety Engineer, Boston Aircraft
Certification Office, 12 New England Executive Park, Burlington, MA
01803, telephone (781) 238-7761, fax (781) 238-7170, for information
about previously approved alternative methods of compliance.
(c) The Joint Aircraft System/Component (JASC) Code is 6520:
Tail rotor gearbox.
(d) The inspections shall be done in accordance with the
specified portions of Sikorsky Special Service Instructions No. 70-
121A, Revision A, dated May 21, 2009. The Director of the Federal
Register approved this incorporation by reference in accordance with
5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from
Sikorsky Aircraft Corporation, Attn: Manager, Commercial Technical
Support, mailstop s581a, 6900 Main Street, Stratford, CT, telephone
(203) 383-4866, e-mail address [email protected], or at http://www.sikorsky.com. Copies may be inspected at the FAA, Office of the
Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663,
Fort Worth, Texas or at the National Archives and Records
Administration (NARA). For information on the availability of this
material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
(e) This amendment becomes effective on December 22, 2010.
Issued in Fort Worth, Texas, on November 1, 2010.
Kim Smith,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2010-28458 Filed 11-16-10; 8:45 am]
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