[Federal Register Volume 78, Number 141 (Tuesday, July 23, 2013)]
[Proposed Rules]
[Pages 44048-44050]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-17631]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2013-0637; Directorate Identifier 2013-SW-030-AD]
RIN 2120-AA64
Airworthiness Directives; Sikorsky Aircraft Corporation
(Sikorsky) Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: We propose to supersede an existing airworthiness directive
(AD) for Sikorsky Model S-76A, B, and C helicopters. The existing AD
currently requires inspecting the main rotor lower bifilar arm assembly
(bifilar arm assembly) for a crack, and if there is a crack, replacing
the bifilar arm assembly. The AD also requires a one-time test for the
correct torque on the lug nuts, and if necessary, conducting torque
stabilization tests. Since we issued that AD, Sikorsky has developed a
terminating procedure for the inspections required by the existing AD.
This proposed AD would retain the requirements of that AD, and would
require replacing the main rotor hub (MRH) pilot with a different part-
numbered MRH pilot, which would be terminating action for the
requirements of the AD. The proposed actions are intended to prevent
failure of a bifilar lug, damage to the main rotor control system, and
subsequent loss of control of the helicopter.
DATES: We must receive comments on this proposed AD by September 23,
2013.
ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Docket: Go to http://www.regulations.gov. Follow the online instructions for sending your
comments electronically.
Fax: 202-493-2251.
Mail: Send comments to the U.S. Department of
Transportation, Docket Operations, M-30, West Building Ground Floor,
Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590-0001.
Hand Delivery: Deliver to the ``Mail'' address 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://www.regulations.gov 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 proposed AD, the economic
evaluation, any comments received and other information. The street
address for the Docket Operations Office (telephone 800-647-5527) is in
the ADDRESSES section. Comments will be available in the AD docket
shortly after receipt.
For service information identified in this proposed AD, contact
Sikorsky Aircraft Corporation, Attn: Manager, Commercial Technical
Support, mailstop s581a, 6900 Main Street, Stratford, CT 06614;
telephone (800) 562-4409; email [email protected]; or at http://www.sikorsky.com. You may review service information at the FAA, Office
of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room
663, Fort Worth, Texas 76137.
FOR FURTHER INFORMATION CONTACT: Nicholas Faust, Aviation Safety
Engineer, Boston Aircraft Certification Office, Engine & Propeller
Directorate, 12 New England Executive Park, Burlington, Massachusetts
01803; telephone (781) 238-7763; email [email protected].
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to participate in this rulemaking by submitting
written comments, data, or views. We also invite comments relating to
the economic, environmental, energy, or federalism impacts that might
result from adopting the proposals in this document. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. To
ensure the docket does not contain duplicate comments, commenters
should send only one copy of written comments, or if comments are filed
electronically, commenters should submit only one time.
We will file in the docket all comments that we receive, as well as
a report summarizing each substantive public contact with FAA personnel
concerning this proposed rulemaking. Before acting on this proposal, we
will consider all comments we receive on or before the closing date for
comments. We will consider comments filed after the comment period has
closed if it is possible to do so without incurring expense or delay.
We may change this proposal in light of the comments we receive.
Discussion
On October 26, 2005, we issued AD 2005-22-01, amendment 39-14345
(70 FR 61721) for Sikorsky Model S-76A, B, and C helicopters with an
MRH pilot part number (P/N) 76103-08003-101 with 1,500 or more hours
time-in-service (TIS) installed. The AD requires, every 50 hours TIS,
inspecting the main rotor lower bifilar arm assembly in the attachment
area around the lower bifilar lugs for a crack. If there is a crack,
the AD requires replacing the bifilar arm assembly. If there is not a
crack, the AD requires a one-time test for the correct torque on the
lug nuts, and if necessary, conducting torque stabilization tests. The
AD was prompted by four reports
[[Page 44049]]
of cracked bifilars. Those actions were intended to prevent failure of
a bifilar lug, damage to the main rotor control system, and subsequent
loss of control of the helicopter.
Actions Since Existing AD Was Issued
Since we issued AD 2005-22-01, Sikorsky issued Alert Service
Bulletin 76-65-65, dated March 22, 2012 (ASB 76-65-65). ASB 76-65-65
specifies measuring the MRH diameter and, if the diameter is small,
replacing the MRH pilot with a newly-redesigned MRH pilot. The new MRH
pilot has a larger flange diameter that provides greater support for
the bifilar assembly and reduces stress on the bifilar assembly
attachment lugs. We propose to supersede AD 2005-22-01 to require
installation of the large diameter MRH pilot as terminating action for
the repetitive inspection requirements. These actions are intended to
prevent failure of a bifilar lug, damage to the main rotor control
system, and subsequent loss of control of the helicopter.
FAA's Determination
We are proposing this AD 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.
Related Service Information
Sikorsky issued S-76 Alert Service Bulletin (ASB) 76-65-62, dated
December 14, 2004 (ASB 76-65-62), which describes procedures to inspect
the lower bifilar assembly for a crack. We have also reviewed ASB 76-
65-65, which specifies measuring the MRH diameter and, if the diameter
is small, replacing the MRH pilot with a newly-redesigned MRH pilot
with a larger flange diameter.
Proposed AD Requirements
This proposed AD would retain the repetitive inspection
requirements of AD 2005-22-01, but would also require replacing the MRH
pilot, P/N 76103-08003-101, with MRH pilot, P/N 76103-08003-102, as
terminating action.
Costs of Compliance
We estimate that this proposed AD would affect 181 helicopters of
U.S. Registry.
We estimate that operators may incur the following costs in order
to comply with this AD. Inspecting the bifilar arm assembly would
require about 4 work-hours, at an average labor rate of $85 per hour,
for a cost per helicopter of $340 and a total cost to U.S. operators of
$61,540.
Replacing a cracked bifilar arm assembly would require about 4
work-hours, at an average labor rate of $85 per hour, and required
parts would cost about $19,727, for a cost per helicopter of $20,067.
Replacing the MRH pilot, P/N 76103-08003-101, with an MRH pilot, P/
N 76103-08003-102, would require about 0.7 work-hour, at an average
labor rate of $85 per hour, and required parts would cost about $1,043,
for a cost per helicopter of $1,103 and a total cost to U.S. operators
of $199,643.
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 proposed 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, I certify this proposed 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);
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 proposed 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.
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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 removing Airworthiness Directive (AD)
2005-22-01, Amendment 39-14345 (70 FR 61721, October 26, 2005), and
adding the following new AD:
Sikorsky Aircraft Corporation: Docket No. FAA-2013-0637; Directorate
Identifier 2013-SW-030-AD.
(a) Applicability
This AD applies to Model S-76A, B, and C helicopters with a main
rotor hub (MRH) pilot, part number (P/N) 76103-08003-101, installed,
certificated in any category.
(b) Unsafe Condition
This AD defines the unsafe condition as a crack on the MRH pilot
bifilar assembly lug, which could result in failure of a bifilar
lug, damage to the main rotor system, and subsequent loss of control
of the helicopter.
(c) Affected ADs
This AD supersedes AD 2005-22-01, Amendment 39-14345 (70 FR
61721, October 26, 2005).
(d) Comments Due Date
We must receive comments by September 23, 2013.
(e) 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.
(f) Required Actions
(1) For MRH pilots with 1,500 or more hours time-in-service
(TIS), within 50 hours TIS, and thereafter at intervals not to
exceed 50 hours TIS, inspect the lower bifilar arm assembly for a
crack in the lug attachment area. Conduct the inspection of the
lower bifilar arm assembly by following the Accomplishment
Instructions, paragraph 3.A.(1) through 3.A.(6), of Sikorsky Alert
Service Bulletin No. 76-65-62, dated December 14, 2004 (ASB 76-65-
62).
[[Page 44050]]
(i) If there is a crack on any bifilar assembly arm lug, before
further flight, replace the bifilar arm assembly with an airworthy
bifilar arm assembly.
(ii) If no crack is found at the initial inspection, perform a
one-time torque test. Perform the torque test and the additional
torque procedures as stated in the Accomplishment Instructions,
paragraph 3.B.(1) through 3.B.(3), of ASB 76-65-62. The torque test
is not required at the recurring inspection intervals of the lower
bifilar arm assembly.
(iii) Within 600 hours TIS, replace the MRH pilot, P/N 76103-
08003-101, with an MRH pilot, P/N 76103-08003-102.
(2) For MRH pilots with less than 900 hours TIS, prior to
accumulating 1,500 hours TIS, replace the MRH pilot, P/N 76103-
08003-101, with a MRH pilot, P/N 76103-08003-102.
(3) After the effective date of this AD, do not install an MRH
pilot, P/N 76103-08003-101, on any helicopter.
(g) Special Flight Permit
Special flight permits will not be issued.
(h) Alternative Methods of Compliance (AMOCs)
(1) The Manager, Boston Aircraft Certification Office, FAA, may
approve AMOCs for this AD. Send your proposal to: Nicholas Faust,
Aviation Safety Engineer, Boston Aircraft Certification Office,
Engine & Propeller Directorate, 12 New England Executive Park,
Burlington, Massachusetts 01803; telephone (781) 238-7763; email
[email protected].
(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.
(i) Additional Information
For service information identified in this AD, contact Sikorsky
Aircraft Corporation, Attn: Manager, Commercial Technical Support,
mailstop s581a, 6900 Main Street, Stratford, CT 06614; telephone
(800) 562-4409; email [email protected]; or at http://www.sikorsky.com. You may review the service information at the FAA,
Office of the Regional Counsel, Southwest Region, 2601 Meacham
Blvd., Room 663, Fort Worth, Texas 76137.
(j) Subject
Joint Aircraft Service Component (JASC) Code: 6220: Main Rotor
Head.
Issued in Fort Worth, Texas, on July 11, 2013.
Kim Smith,
Directorate Manager, Rotorcraft Directorate, Aircraft Certification
Service.
[FR Doc. 2013-17631 Filed 7-22-13; 8:45 am]
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