Daily Rules, Proposed Rules, and Notices of the Federal Government
On January 8, 2010, the Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD.
To view the AD docket, go to U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, or on the Internet at
On August 21, 2009, 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 certain Twin Commander Aircraft LLC Models 690, 690A, and 690B airplanes. This proposal was published in the
We provided the public the opportunity to participate in developing this AD. The following presents the comments received on the proposal and FAA's response to each comment:
Michael Curtis Pidek, William I. Smith, and Tom Bayer all state that with 275 airplanes affected by this AD and only 15 service centers available to do the actions required in this AD, there is not enough time to comply with the AD.
All three commenters request an extension of the compliance time to allow enough time for the service centers to schedule the work without grounding airplanes until the work can be done.
We do not agree with the commenters. Over 65 airplanes are already in compliance with this AD. We have consulted with Twin Commander Aircraft LLC and they have covered this issue with the service centers. The service centers know how much work is required since they have already done the work on over 65 of the affected airplanes. The service centers plan on using multiple teams to work on several airplanes at the same time. They have confirmed they can perform the actions required in this AD in the compliance time as proposed.
Part of the alternative method of compliance (AMOC) provisions of 14 CFR 39.19 is an extension of the compliance time provided a level of safety acceptable to the FAA is met. The FAA will review any AMOCs of this nature on a case-by-case basis. If we determine the proposal presents an acceptable level of safety, we will approve it as an AMOC to the AD.
We are not changing the final rule AD action based on these comments.
We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed except for minor editorial corrections. We have determined that these minor corrections:
• Are consistent with the intent that was proposed in the NPRM for correcting the unsafe condition; and
• Do not add any additional burden upon the public than was already proposed in the NPRM.
We estimate that this AD will affect 275 airplanes in the U.S. registry.
We estimate the following costs to do the inspection:
We estimate the following costs to do any necessary repairs/replacements that will be required based on the results of the inspection. We have no way of determining the number of airplanes that may need this repair/replacement:
* Depending on airplane configuration, airplanes with rectangular plates will need the Plate and Hardware Kit (SB237-4) at $2,090 per side. Labor to install this kit is included in Options A, B, and C.
We estimate the following costs to do the installation of access holes:
We estimate the following costs to do the wing fastener modification:
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 AD.
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 this AD:
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 summary of the costs to comply with this AD (and other information as included in the Regulatory Evaluation) and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
49 U.S.C. 106(g), 40113, 44701.
(a) This AD becomes effective on January 8, 2010.
(c) This AD applies to the following airplane models and serial numbers that are certificated in any category:
(d) This AD results from reports that corrosion was found between the mating surfaces of the wing upper skin surface and the engine mount beam support straps. We are issuing this AD to detect and correct corrosion on the engine mount beam support straps and upper wing skins, which could result in failure of the engine mount beam support straps. This failure could lead to loss of the engine and possible loss of control of the airplane.
(e) To address this problem, you must do the following, unless already done:
Although not required by this AD, we highly recommend compliance with Twin Commander Aircraft Corporation Service Bulletin No. 217, Revision No. 1, dated May 26, 1993, Engine Nacelle Firewall Reinforcement; and Twin Commander Aircraft LLC Alert Service Bulletin No. 239, dated February 13, 2006, Outboard Flap—Inboard Hinge Inspection Reinforcement.
(f) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Vince Massey, Aerospace Engineer, FAA, Seattle ACO, 1601 Lind Avenue, SW, Renton, Washington 98057-3356; telephone: (425) 917-6475; fax: (425) 917-6590; email:
(g) You must use Twin Commander Aircraft LLC Alert Service Bulletin No. 237, dated May 13, 2005; Twin Commander Aircraft Corporation Custom Kit No. 150, dated July 8, 1994; and Gulfstream American Corporation Service Bulletin No. 182, dated March 2, 1981, to do the actions required by this AD, unless the AD specifies otherwise.
(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) For service information identified in this AD, contact Twin Commander Aircraft LLC, 18933—59th Avenue, NE., Arlington, WA 98223, telephone: (360) 435-9797; fax: (360) 435-1112; Internet:
(3) You may review copies of the service information incorporated by reference for this AD at the FAA, Central Region, Office of the Regional Counsel, 901 Locust, Kansas City, Missouri 64106. For information on the availability of this material at the Central Region, call (816) 329-3768.
(4) You may also review copies of the service information incorporated by reference for this AD 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: