Discussion
We issued an NPRM to amend 14 CFR part 39 to include an AD that would apply to BHTC Model 430 helicopters, serial numbers 49001 through 49122, on November 2, 2007. That NPRM was published in the Federal Register on November 16, 2007 (72 FR 64540). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states: "It has been determined that the existing rigging procedures for the tail rotor pitch change mechanism have to be changed due to possibility of parts interference.'' Because the cumulative effect of the tolerances on the various parts may result in the total assemblage outboard of the counterweight bellcrank being out of tolerance, the tail rotor yoke may contact the nut, part number (P/N) 222-012-731-001, before contacting the flapping stop, resulting in less tail rotor travel. Additionally, the manufacturer has indicated that the tail rotor counterweight bellcranks may be misaligned, resulting in higher tail rotor pedal forces and higher pilot workload after failure of the 1 hydraulic system. Both the parts interference and the higher pedal forces constitute unsafe conditions. You may obtain further information by examining the MCAI and any related service information in the AD docket.
Comments
By publishing the NPRM, we gave the public an opportunity to participate in developing this AD. However, we received no comment on the NPRM or on our determination of the cost to the public. Therefore, based on our review and evaluation of the available data, we have determined that air safety and the public interest require adopting the AD as proposed.
Relevant Service Information
Bell Helicopter Textron has issued Alert Service Bulletin No. 430- 07-39, dated January 9, 2007, that describes revised rigging procedures for the tail rotor pitch change mechanism. The actions described in the MCAI are intended to correct the same unsafe condition as that identified in the service information.
Differences Between This AD and the MCAI
We have reviewed the MCAI and related service information and, in general, agree with their substance. However, this AD requires compliance within the next 150 hours time-in-service or at the next annual inspection, whichever occurs first, instead of "at the next 150 hour or annual inspection, but no later than 31 December 2007.'' In making this change, we do not intend to differ substantively from the information provided in the MCAI. This difference is highlighted in the "Differences Between this AD and the MCAI'' section in the AD.
Costs of Compliance
We estimate that this AD will affect 58 helicopters of U.S. registry. We also estimate that it will take about 2 work-hours per helicopter to comply with the basic requirements of this AD. The average labor rate is $80 per work-hour. A replacement yoke will cost about $21,218, assuming the part is no longer under warranty. However, because the service information lists this part as covered under warranty, we have assumed that there will be no charge for this part. Therefore, as we do not control warranty coverage for affected parties, some parties may incur costs higher than estimated here. Based on these assumptions and figures, we estimate the cost of this AD on U.S. operators to be $9,280, or $160 per helicopter.
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.
Regulatory Findings
We 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.
Therefore, I certify 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 an economic evaluation of the estimated costs to comply with this AD and placed it in the AD docket.
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 FAA amends 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. The FAA amends Sec. 39.13 by adding the following new AD: