Airworthiness Directives; MD Helicopters, Inc. Model MD900 Helicopters
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.
1 action from November 2013
- Actions Will Continue Through
Table of Contents Back to Top
DATES: Back to Top
Effective December 13, 2011.
ADDRESSES: Back to Top
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 http://www.mdhelicopters.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: Back to Top
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: Back to Top
Discussion Back to Top
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 Back to Top
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 Back to Top
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.
Adoption of the Amendment Back to Top
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 Back to Top
1.The authority citation for part 39 continues to read as follows:
§ 39.13 [Amended]
2.The FAA amends § 39.13 by removing Amendment 39-15756 (73 FR 73165, December 2, 2008), and adding the following new AD:
2011-22-08MD 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 Back to Top
Model MD900 helicopters with a Vertical Stabilizer Control System (VSCS) tube adapter, part number (P/N) 500N7218-1, installed, certificated in any category.
Compliance Back to Top
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).
(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 NE, 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 NE is limited to 100 KIAS or less as determined by referring to the airspeed V NE 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 http://www.mdhelicopters.com. 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]
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