Document ID: FAA-2010-1250-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Sikorsky Aircraft Corp. Model  S76A; B; and C; and Helicopters
Posted Date: 2010-12-28T05:00Z

[Federal Register Volume 75, Number 248 (Tuesday, December 28, 2010)]
[Rules and Regulations]
[Pages 81424-81427]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-31962]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-1250; Directorate Identifier 2010-SW-075-AD; 
Amendment 39-16548; AD 2010-26-09]
RIN 2120-AA64

Airworthiness Directives; Sikorsky Aircraft Corporation 
(Sikorsky) Model S76A, B, and C Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment supersedes an existing emergency airworthiness 
directive (EAD) for the specified Sikorsky model helicopters. The EAD 
requires inspecting the LITEF Attitude Heading and Reference System 
(AHRS) unit of the navigation system to determine if it is at a Mod 
Status ``18.'' If either AHRS unit is at Mod Status ``18,'' the EAD 
requires installing placards on the instrument panel to prohibit single 
pilot instrument flight rule (IFR) and single pilot night flight and 
reducing airspeeds to 120 knots indicated airspeed (KIAS) if both 
autopilots uncouple during instrument meteorological conditions (IMC) 
or night flight. The EAD also requires inserting minimum crew and 
airspeed limitations into the Limitations section of the applicable 
Rotorcraft Flight Manual (RFM) to limit the minimum

[[Page 81425]]

flight crew to 2 pilots for night flight and IFR flight and to reduce 
airspeed to 120 KIAS if both autopilots uncouple during IMC or night 
flight. This amendment contains the same requirements but draws the 
appropriate distinctions between IFR and IMC as used in the intended 
operating limitations. Also, unlike the EAD, this AD states the 
airspeed must be reduced to 120 KIAS if both autopilots uncouple during 
IMC or night flight. Further, we are removing the limitation contained 
in the Active Temporary Revisions relating to pilots keeping their 
hands and feet near the flight controls. This AD was prompted by the 
need to supersede the EAD to state the distinction between IFR and IMC 
as used in the operating limitations and to reduce the airspeed to 120 
KIAS if both autopilots uncouple during IMC or night flight. The 
actions specified by this AD are intended to implement operating 
limitations based on an anomaly in the AHRS related to the 26 volt AC 
inverter that could result in a decoupling of both autopilots and to 
prevent loss of control of the helicopter during IMC and during night 
flight.

DATES: Effective January 12, 2011.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of January 12, 2011.
    We must receive comments on this AD by February 28, 2011.

ADDRESSES: Use one of the following addresses to comment on this AD.
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: (202) 493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    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 tsslibrary@sikorsky.com, or at http://www.sikorsky.com.
    Examining the Docket: You may examine the docket that contains the 
AD, any comments, and other information 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 Docket Operations office (telephone (800) 647-5527) is 
located in Room W12-140 on the ground floor of the West Building at the 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Tony Pigott, Aviation Safety Engineer, 
Boston Aircraft Certification Office, 12 New England Executive Park, 
Burlington, MA 01803, telephone (781) 238-7158, fax (781) 238-7170.

SUPPLEMENTARY INFORMATION: On May 19, 2010, we issued EAD No. 2010-11-
52, to require inspecting the AHRS unit to determine if it is at a Mod 
Status ``18.'' If the nameplate indicates that either AHRS unit is a 
Mod Status ``18,'' the EAD requires installing placards on the 
instrument panel to prohibit single pilot IFR and single pilot night 
flight and reducing airspeeds to 120 KIAS if both autopilots uncouple 
during IMC or night flight. The EAD also requires inserting the Active 
Temporary Revision listed in Table 1 into the Limitations section of 
the RFM to limit the minimum flight crew to 2 pilots for IFR and night 
flight. That action was prompted by reports of intermittent 
malfunctions of the LITEF AHRS units of the navigation system. The EAD 
states that the condition, if not corrected, could result in 
malfunction of the autopilots, inability to reset the autopilots, an 
uncommanded roll, reduction in rotorcraft functional capabilities, 
inability of the crew to perform the required tasks, and subsequent 
loss of control of the helicopter.
    Since issuing EAD 2010-11-52, we have discovered that we did not 
draw the appropriate distinctions between IFR and IMC as used in the 
intended operating limitations, and we did not state the requirement to 
reduce the airspeed to 120 KIAS if both autopilots uncouple during IMC 
or night flight. Further, we did not intend to adopt as a limitation 
the provision contained in the Active Temporary Revisions relating to 
pilots keeping their hands and feet near the flight controls as this is 
considered normal conduct of a helicopter pilot exercising good care 
and sound judgment regardless of the AHRS unit installed.
    We have reviewed Sikorsky Alert Service Bulletin No. 76-34-11, 
dated May 17, 2010 (ASB). The ASB specifies informing operators of an 
interim minimum flight crew restriction of two pilots for IFR and night 
flight for helicopters equipped with LITEF LCR-100, Mod Status ``18,'' 
AHRS units. The ASB also specifies removing and inspecting the AHRS 
units to determine if part number (P/N) 145130-7100, Mod Status ``18,'' 
is installed, and if it is installed, identifying the unit with a 
placard with a different P/N. Finally, the ASB specifies installing 2 
placards, P/N SS9140-1746, or locally fabricated placards, one on each 
side of the instrument panel.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other Sikorsky model helicopters of these same type 
designs, this AD supersedes EAD 2010-11-52 by retaining the current 
requirements but by clarifying the appropriate distinctions between IFR 
and IMC as used in the intended operating limitations. Also, in this AD 
we state the requirement to reduce the airspeed to 120 KIAS if both 
autopilots uncouple during IMC or night flight. Further, we have 
removed the Active Temporary Revisions to correct the provision 
relating to pilots keeping their hands and feet near the flight 
controls. In the place of the Active Temporary Revisions, we are now 
requiring you to insert a copy of this AD into the Limitations section 
of the applicable RFM to address the airspeed limitations and the 
minimum flight crew. Accomplish the actions in this AD by following 
specified portions of the ASB described previously. This AD does not 
require installing placards containing the Sikorsky P/N 76070-60019-101 
on the AHRS unit as specified in the Sikorsky ASB. Also, this AD 
revises the unsafe condition statement by stating that the actions are 
intended to implement operating limitations based on an anomaly in the 
AHRS related to the 26 volt AC inverter that could result in a 
decoupling of both autopilots and to prevent loss of control of the 
helicopter during IMC and night flight.
    The short compliance time involved is required because the 
previously described critical unsafe condition can adversely affect the 
controllability of the helicopter. Therefore, determining if the AHRS 
unit is an affected unit, installing certain placards on the instrument 
panel, and inserting limitations into the Limitations section of the 
applicable RFM are required within 5 days, and this AD must be issued 
immediately.
    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

[[Page 81426]]

    We estimate that this AD will affect 1 helicopter in the U.S. 
registry. We estimate it will take about 1 work hour to inspect the 
AHRS unit to determine if it is a Mod Status ``18,'' 1 work hour to 
fabricate and install a placard, and \1/2\ work hour to revise the RFM. 
The average labor rate is $85 per hour and there are only minimal parts 
costs. Based on these figures, the total cost impact of this AD on U.S. 
operators is $213.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety, and we did not precede it by notice and an opportunity for 
public comment. We invite you to send any written relevant data, views, 
or arguments regarding this AD. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2010-1250; 
Directorate Identifier 2010-SW-075-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the AD. We will consider 
all comments received by the closing date and may amend the AD in light 
of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive concerning this AD. Using the search function of the docket Web 
site, you can find and read the comments to any of our dockets, 
including the name of the individual who sent the comment. You may 
review the DOT's complete Privacy Act Statement in the Federal Register 
published on April 11, 2000 (65 FR 19477-78).

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 
rulemaking action.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
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 a new AD to read as follows:

2010-26-09 Sikorsky Aircraft Corporation: Amendment 39-16548; Docket 
No. FAA-2010-1250; Directorate Identifier 2010-SW-075-AD. Supersedes 
EAD 2010-11-52; Directorate Identifier 2010-SW-059-AD.
    Applicability: Model S-76A, B, and C helicopters, with LITEF 
LCR-100, Attitude Heading and Reference System (AHRS) Unit, part 
number (P/N) 145130-7100, installed, certificated in any category.
    Compliance: Within 5 days, unless accomplished previously, and 
any time thereafter when installing a LITEF LCR-100, AHRS Unit, P/N 
145130-7100.
    To implement operating limitations based on an anomaly in the 
AHRS related to the 26-volt AC inverter that could result in a 
decoupling of both autopilots and to prevent loss of the helicopter 
during instrument meteorological conditions (IMC) and while 
operating under instrument flight rules (IFR) and night flight, do 
the following:
    (a) By referencing the nameplate of the No. 1 and No. 2 AHRS 
unit, determine whether the modification (Mod) status is at ``18.'' 
If the Mod status is ``18'' for either AHRS unit:
    (1) Install instrument panel placards as shown in Figure 2 in 
the areas depicted in Figure 3 of Sikorsky Alert Service Bulletin 
No. 76-34-11, dated May 17, 2010 (ASB), and by following the 
Accomplishment Instructions, paragraph 3.A.(6)(c) through (d) of the 
ASB.
    (2) Revise the ``Minimum Flight Crew'' section of the Operating 
Limitations section of the Rotorcraft Flight Manual (RFM) as 
follows: ``For helicopters with an LCR-100 Mod Status `18' AHRS 
installed, two pilots are required for IFR and night flights.''
    (3) Revise the ``Airspeed Limits'' section of the Operating 
Limitations section of the RFM as follows: ``For helicopters with an 
LCR-100 Mod Status `18' AHRS installed, airspeed is limited to 120 
knots indicated airspeed (KIAS) when both autopilots are uncoupled 
and operating at night or in IMC.''
    (4) When present, remove and discard the following Active 
Temporary Revisions from the Operating Limitations section of the 
RFM for each affected helicopter:

                                 Table 1
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                                                       Active temporary
              Model                RFM document No.        rev. No.
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S-76A...........................  SA-4047-76-1......  T-Revision 3.
S-76B...........................  SA 4047-76B-1.....  T-Revision 3.
S-76C (TurboMeca Arriel 1S1       SA 4047-76C-1.....  T-Revision 3.
 engines installed).
S-76C (TurboMeca Arriel 2S1       SA 4047-76C-10....  T-Revision 4.
 engines installed).
S-76C (TurboMeca Arriel 2S1       SA 4047-76C-14....  T-Revision 4.
 engines installed and s/n
 760511 and subsequent).
S-76C (TurboMeca Arriel 2S2       SA 4047-76C-15....  T-Revision 1.
 engines installed).
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[[Page 81427]]

    (5) Revise the Operating Limitations section of the RFM by 
inserting a copy of this AD into the appropriate section of the RFM.
    (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: Tony Pigott, Aviation Safety Engineer, 12 New England 
Executive Park, Burlington, MA 01803, telephone (781) 238-7158, fax 
(781) 238-7170.
    (c) The Joint Aircraft System/Component (JASC) Code is 3420: 
Navigation.
    (d) Installing the placards shall be done by following the 
specified portions of Sikorsky Alert Service Bulletin No. 76-34-11, 
dated May 17, 2010. 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 tsslibrary@sikorsky.com, 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 January 12, 2011.

    Issued in Fort Worth, Texas, on December 13, 2010.
Lance T. Gant,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2010-31962 Filed 12-27-10; 8:45 am]
BILLING CODE 4910-13-P