
[Federal Register Volume 76, Number 10 (Friday, January 14, 2011)]
[Proposed Rules]
[Pages 2607-2609]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-726]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-1301; Directorate Identifier 2010-SW-008-AD]
RIN 2120-AA64


Airworthiness Directives; MD Helicopters, Inc. (MDHI) Model MD900 
Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes superseding an existing airworthiness 
directive (AD) for MDHI Model MD900 helicopters. That AD currently 
requires turning on both Vertical Stabilizer Control System (VSCS) 
switches and turning off the autopilot (AP/SAS) switch; pulling certain 
AP/SAS circuit breakers; installing a placard near the AP/SAS master 
switch; installing an airspeed limitation placard on the instrument 
panel; and making changes to the Rotorcraft Flight Manual (RFM). This 
action would retain those requirements and would provide an option of 
replacing each affected tube adapter with a newly-designed tube 
adapter, which would provide terminating action for the unsafe 
condition. This proposal is prompted by the manufacturer introducing an 
improved, newly-designed tube adapter. The actions specified by this AD 
are intended to prevent loss of yaw control and subsequent loss of 
control of the helicopter.

DATES: Comments must be received on or before March 15, 2011.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed 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 proposed AD 
from MD Helicopters, Inc., Attn: Customer Support Division, 4555 E. 
McDowell Rd., Mail Stop M615, Mesa, AZ 85215-9734, telephone 1-800-388-
3378, fax 480-346-6813, or at http://www.mdhelicopters.com.
    You may examine the comments to this proposed AD in the AD docket 
on

[[Page 2608]]

the Internet at http://www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: Eric D. Schrieber, FAA, Los Angeles 
Aircraft Certification Office, Aviation Safety Engineer, Airframe 
Branch, 3960 Paramount Blvd., Lakewood, California 90712, telephone 
562-627-5348, fax 562-627-5210.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any written data, views, or arguments 
regarding this proposed AD. Send your comments to the address listed 
under the caption ADDRESSES. Include the docket number ``FAA-2010-1301, 
Directorate Identifier 2010-SW-008-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed 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 
with FAA personnel concerning this proposed rulemaking. 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 or signed 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).

Examining the Docket

    You may examine the docket that contains the proposed AD, any 
comments, and other information 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.

Discussion

    On August 20, 2008, we issued Emergency AD (EAD) 2008-18-51, 
Directorate Identifier 2008-SW-50-AD, for Model 500N, 600N, and MD900 
helicopters. That EAD required several actions related to the Yaw 
Stability Augmentation System (YSAS) for the Model 500N and 600N 
helicopters and to the VSCS for the Model MD900 helicopters.
    We issued superseding EAD 2008-18-52, Directorate Identifier 2008-
SW-52-AD, on August 27, 2008. That EAD required, for Model 500N, 600N 
and MD900 helicopters, turning OFF the VSCS or YSAS switches instead of 
pulling the circuit breakers and installing placards that limit 
airspeed to 100 KIAS or VNE, whichever is less. For the 
Model MD900 helicopters, the EAD also required limiting flight to VFR, 
prohibiting use of the autopilot, and making changes to the RFM. For 
all helicopters, the EAD required a terminating action of replacing 
each tube adapter with an airworthy tube adapter stamped with a date 
stamp of August 15, 2008, or later.
    After issuing EAD 2008-18-52, the replacement tube adapter failed 
on 2 of the Model MD900 helicopters. Therefore, we separated the AD 
actions and issued two superseding EADs: 2008-22-52 for the Model 500N 
and 600N helicopters and 2008-22-53 for the Model MD900 helicopters. 
Those EADS were published in the Federal Register as final rules; 
request for comments. AD 2008-22-52 (73 FR 72326) was published on 
November 28, 2008. AD 2008-22-53 (73 FR 73165) was published on 
December 2, 2008.
    AD 2008-22-53 does not include specific serial numbers in the 
applicability section because the unsafe condition can occur on any 
helicopter with an affected tube adapter installed. The AD also 
requires turning ON both VSCS switches to reduce pilot workload and to 
help control the helicopter if a tube adapter fails under normal flight 
conditions until the helicopter is on final approach. Also, AD 2008-22-
53 did not include a terminating action because the manufacturer had 
not determined the cause of the failures.
    Since issuing AD 2008-22-53, the manufacturer has designed a VSCS 
tube adapter to replace the existing tube adapter. Installing the newly 
designed tube adapter is optional but, if installed, would constitute 
terminating action for the requirements of this AD.
    We have reviewed MDHI Service Bulletin No. SB900-110R1, dated 
December 3, 2008 (SB), which specifies replacing each VSCS tube 
adapter, part number (P/N) 500N7218-1, with an improved tube adapter, 
P/N 900C2010303-101, to prevent an uncommanded yaw of the helicopter. 
The SB specifies operating at a decreased speed until the newly 
designed tube adapters are installed.
    This previously described unsafe condition is likely to exist or 
develop on other helicopters of this same type design. Therefore, the 
proposed AD would supersede AD 2008-22-53, retain the current 
requirements, and require continuing to operate at a reduced speed 
until you replace each tube adapter with an improved tube adapter.
    We estimate that this proposed AD would affect 39 helicopters of 
U.S. registry. It would take about 5.5 hours to install the newly 
designed tube adapters and 0.5 hours for all other required 
modifications at an average labor rate of $85 per work hour. Required 
parts would cost about $244 for 2 tube adapters. Based on these 
figures, we estimate the total cost impact of the proposed AD on U.S. 
operators to be $29,406, assuming both tube adapters are replaced on 
the entire fleet of helicopters.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. Additionally, 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 above, I certify that the 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); 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 a draft economic evaluation of the estimated costs to 
comply with this proposed AD. See the AD docket to examine the draft 
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

[[Page 2609]]

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, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (14 CFR part 39) as 
follows:

PART 39--AIRWORTHINESS DIRECTIVES

    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]

    2. Section 39.13 is amended by removing Amendment 39-15756 (73 FR 
73165, December 2, 2008), and by adding a new airworthiness directive 
(AD), to read as follows:

MD Helicopters, Inc.: Docket No. FAA-2010-1301; Directorate 
Identifier 2010-SW-008-AD. Supersedes AD 2008-22-53, Amendment 39-
15756, Docket No. FAA-2008-1251, Directorate ID 2008-SW-61-AD.
    Applicability: Model MD900 helicopters with a Vertical 
Stabilizer Control System (VSCS) tube adapter, part number (P/N) 
500N7218-1, installed, certificated in any category.
    Compliance: Required before further flight, unless done 
previously.
    To prevent loss of yaw control and subsequent loss of control of 
the helicopter, do the following:
    (a) Turn ON both VSCS switches.
    (b) If installed, de-energize the autopilot (AP/SAS) as follows:
    (1) Determine if the AP/SAS trim actuators are centered. If the 
AP/SAS trim actuators are not centered, center them.
    (2) After the AP/SAS trim actuators are centered:
    (i) Turn the AP/SAS MSTR switch to the OFF position.
    (ii) Pull the following AP circuit breakers located on the A601 
Essential Bus Circuit Breaker Panel, mounted in the cockpit console, 
and install a plastic cable tie on each circuit breaker to prevent 
accidental energizing of the circuit:
    (A) AP/SAS CMPTR (CB28),
    (B) AP/SAS DISC (CB29), and
    (C) AP/SAS ACCEL (CB30).
    (3) Install a placard next to the AP Mode Select panel that 
contains the AP/SAS MSTR switch stating ``AP/SAS DEACTIVATED.''
    (c) Install a placard on the instrument panel as close as 
practicable to the airspeed indicator that states:
    ``AIRSPEED LIMIT 100 KIAS or VNE, WHICHEVER IS LESS. 
VFR FLIGHT ONLY, AUTOPILOT OFF.''
    (d) Make pen and ink changes or insert a copy of this AD into 
the Limitations section of the rotorcraft flight manual (RFM) to 
revise the limitations as follows: ``VNE is limited to 
100 KIAS or less as determined by referring to the airspeed 
VNE placard already installed on the helicopter. VFR 
Flight Only, Autopilot OFF.''
    (e) Make pen and ink changes or insert a copy of this AD into 
the Limitations section of the RFM to revise the emergency 
procedures as follows: ``If you experience an anti-torque system 
malfunction, turn both VSCS switches to OFF during final approach 
for a run-on landing.''
    (f) Instead of complying with paragraphs (a) through (e) of this 
AD, you may replace both VSCS tube adapters, P/N 500N7218-1, with 
airworthy VSCS tube adapters, P/N 900C2010303-101. If you install 
VSCS tube adapters, P/N 900C2010303-101, and previously have 
complied with AD 2008-22-53, return the helicopter to its normal 
configuration by returning the switches and circuit breakers to 
their normal operating position, operationally testing the auto-
pilot system, removing the two placards, and removing the revisions 
to the RFM pertaining to the airspeed limitation. Replacing both 
VSCS tube adapters, P/N 500N7218-1, with airworthy VSCS tube 
adapters, P/N 900C2010303-101, and returning the helicopter to its 
normal operating configuration constitutes terminating action for 
the requirements of this AD.

    Note:  MD Helicopters Service Bulletin SB900-110R1, dated 
December 3, 2008, which is not incorporated by reference containing 
additional information about the subject of this AD.

    (g) 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, Los Angeles Aircraft Certification Office, FAA, 
Attn: Eric D. Schrieber, Aviation Safety Engineer, Airframe Branch, 
3960 Paramount Blvd., Lakewood, California 90712, telephone 562-627-
5348, fax 562-627-5210, for information about previously approved 
alternative methods of compliance.
    (h) Copies of the applicable service information may be obtained 
from MD Helicopters, Inc., Attn: Customer Support Division, 4555 E. 
McDowell Rd., Mail Stop M615, Mesa, Arizona 85215-9734, telephone 1-
800-388-3378, fax 480-346-6813, or on the Web at http://www.mdhelicopters.com.
    (i) The Joint Aircraft System/Component (JASC) Code is 6720: 
Tail Rotor Control System.

    Issued in Fort Worth, Texas, on December 28, 2010.
Stefany James,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2011-726 Filed 1-13-11; 8:45 am]
BILLING CODE 4910-13-P


