AD 2011-22-08

final rule

Airworthiness Directives; MD Helicopters, Inc. Model MD900 Helicopters

AD Number
2011-22-08
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. FAA-2010-1301
FR Citation
76 FR 69123
Technical illustration of an aircraft flight control surface and actuator
Problem area Flight controls

Applicability

TypeManufacturerModelDetails
aircraft MD Helicopters, Inc. MD900 Airworthiness Directives; MD Helicopters, Inc. Model MD900 Helicopters

Unsafe Condition

Failure of the Vertical Stabilizer Control System (VSCS) tube adapter, part number 500N7218-1, could lead to loss of yaw control and subsequent loss of control of the helicopter.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Turn ON both VSCS switches. De-energize the autopilot (AP/SAS) by centering the trim actuators, turning off the AP/SAS MSTR switch, and pulling specific circuit breakers. Install placards for AP/SAS deactivation and airspeed limitation. Revise the Rotorcraft Flight Manual (RFM) for limitations and emergency procedures. Alternatively, replace both VSCS tube adapters with newly-designed airworthy adapters, P/N 900C2010303-101, to terminate the AD requirements.

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

MD Helicopters, Inc. Model MD900 helicopters with a Vertical Stabilizer Control System (VSCS) tube adapter, part number 500N7218-1, installed, certificated in any category.

AI-generated summary from the source AD text. Verify against the official source before acting.

Federal Register Abstract

This amendment supersedes an existing airworthiness directive (AD) that applies to MD Helicopters, Inc. (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 amendment retains those requirements and provides an option of replacing each affected tube adapter with a newly-designed tube adapter, which provides terminating action for the unsafe condition. This amendment 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.

Document Text

Show stored source text (verify against official source)
[Federal Register Volume 76, Number 216 (Tuesday, November 8, 2011)]
[Rules and Regulations]
[Pages 69123-69125]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2011-28897]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-1301; Directorate Identifier 2010-SW-008-AD; 
Amendment 39-16851; AD 2011-22-08]
RIN 2120-AA64


Airworthiness Directives; MD Helicopters, Inc. Model MD900 
Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

[[Page 69124]]

SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD) that applies to MD Helicopters, Inc. (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 amendment retains those 
requirements and provides an option of replacing each affected tube 
adapter with a newly-designed tube adapter, which provides terminating 
action for the unsafe condition. This amendment 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: Effective December 13, 2011.

ADDRESSES: You may get the service information identified in this 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 <a href="http://www.mdhelicopters.com">http://www.mdhelicopters.com</a>.
    Examining the Docket: You may examine the docket that contains this 
AD, any comments, and other information on the Internet at <a href="http://www.regulations.gov">http://www.regulations.gov</a>, or at the Docket Operations office, West Building 
Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC.

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: 

Discussion

    On December 28, 2010, we issued a proposal to amend part 39 of the 
Federal Aviation Regulations (14 CFR part 39) to include an AD that 
would apply to all MDHI Model MD900 helicopters with a VSCS tube 
adapter, part number 500N7218-1, installed. This proposal was published 
in the Federal Register as a notice of proposed rulemaking (NPRM) on 
January 14, 2011 (76 FR 2607). The NPRM proposed to supersede AD 2008-
22-53 (73 FR 73165, December 2, 2008), retain the current requirements, 
and require continuing operations at a reduced speed until each tube 
adapter is replaced with an improved tube adapter.
    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. We have determined that air 
safety and the public interest require adopting the AD as proposed.
    We estimate that this AD will affect 39 helicopters of U.S. 
registry. It will 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 will cost about 
$244 for 2 tube adapters. Based on these figures, we estimate the total 
cost impact of this AD on U.S. operators is $29,406, assuming both tube 
adapters are replaced on the entire fleet of helicopters.

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

    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:

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 Amendment 39-15756 (73 FR 
73165, December 2, 2008), and adding the following new AD:

2011-22-08 MD Helicopters, Inc. Model MD900 Helicopters: Amendment 
39-16851; Docket No. FAA-2010-1301; Directorate Identifier 2010-SW-
008-AD. Supersedes AD 2008-22-53, Amendment 39-15756 (73 FR 73165, 
December 2, 2008), 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 accomplished 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).

[[Page 69125]]

    (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 V<INF>NE</INF>, 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: ``V<INF>NE</INF> is limited to 
100 KIAS or less as determined by referring to the airspeed 
V<INF>NE</INF> 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 (73 FR 73165, December 2, 2008), 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, contains 
additional information about the subject of this AD. Copies of this 
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 <a href="http://www.mdhelicopters.com">http://www.mdhelicopters.com</a>. This service 
information may be inspected at the FAA, Office of the Regional 
Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, 
Texas 76137.

    (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) The Joint Aircraft System/Component (JASC) Code is 6720: 
Tail Rotor Control System.
    (i) This amendment becomes effective on December 13, 2011.

    Issued in Fort Worth, Texas, on October 18, 2011.
Lance T. Gant,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2011-28897 Filed 11-7-11; 8:45 am]
BILLING CODE 4910-13-P

Source: Official FAA Source ↗

Retrieved: Apr 6, 2026

Rights: U.S. Government Public Domain

This site is not affiliated with or endorsed by the FAA. Always verify with official sources.