These differences are highlighted in the ``Differences Between this AD and the MCAI'' section in the AD.

Costs of Compliance

We estimate that this proposed AD would affect about 17 products of U.S. registry. We also estimate that it would take about 2 workhours per helicopter to remove and visually inspect the vertical fin and the tail rotor gearbox attachment legs and to reinstall the vertical fin. The average labor rate is $80 per workhour. Required parts would cost about $227 per helicopter. Based on these figures, we estimate the cost of the proposed AD on U.S. operators to be $6,579 for the fleet, or $387 per helicopter, to perform the inspections and remove and re install the vertical fin.

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 helicopters identified in this rulemaking action.

Regulatory Findings

We determined that this proposed AD would not have federalism implications under Executive Order 13132. 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 this 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 an economic evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety. The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows: PART 39AIRWORTHINESS 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: Bell Helicopter Textron Canada (BHTC): Docket No. FAA20090227; Directorate Identifier 2007SW65AD.
Comments Due Date
(a) We must receive comments by April 22, 2009.
Other Affected ADs
(b) None.
Applicability
(c) This AD applies to Model 427 helicopters, serial numbers 56001 through 56057, 58001, and 58002, certificated in any category. Reason
(d) Transport Canada states in the mandatory continuing airworthiness information (MCAI) that it has been determined that the existing hardware connecting the vertical fin to the tail rotor gearbox need to be upgraded, to prevent the vertical fin from becoming loose. BHTC has received reports of loose vertical fins discovered during inspections. Investigation revealed that the current vertical fin attachment hardware may not provide adequate clampup. If not corrected, the vertical fin could become loose and cause vibration, which could lead to subsequent loss of control of the helicopter.
Actions and Compliance
(e) Within the next 150 hours timeinservice, unless already done, do the following:
(1) Remove the vertical fin and visually inspect the inboard and outboard surfaces of the vertical fin where it attaches to the tail rotor gearbox support for a crack, an elongated bolt hole, fretting, distortion and corrosion.
(2) Visually inspect the tail rotor gearbox support attachment legs for a crack, fretting and corrosion.
(f) If a crack, elongated bolt hole, fretting, distortion or corrosion is detected, repair or replace the part with an airworthy part before further flight.
(g) Reinstall the vertical fin.
Differences Between This AD and the MCAI
(h) This AD differs from the MCAI as follows:
(1) We do not require compliance ``no later than November 27, 2007'', because that date has passed.
(2) We refer to the compliance time as ``hours timeinservice'' rather than ``air time hours.''
Other Information
(i) Alternative Methods of Compliance (AMOCs): The Manager, Safety Management Group, 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: Sharon Miles, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Regulations and Guidance Group, Fort Worth, Texas 761930111, telephone (817) 2225122, fax (817) 222 5961.
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Related Information
(j) Mandatory Continuing Airworthiness Information (MCAI) Transport Canada Airworthiness Directive CF200722, dated September 14, 2007, and Bell Helicopter Textron Alert Service Bulletin No. 4270615, dated December 14, 2006, contain related information. Subject
(k) Air Transport Association of America (ATA) Code:5553, Vertical Stabilizer, Attach Fittings.

Issued in Fort Worth, Texas, on March 4, 2009.
Jerald E. Strentz,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. E96225 Filed 32009; 8:45 am]
BILLING CODE 491013P

FOR FURTHER INFORMATION CONTACT

Sharon Miles, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Regulations and Guidance Group, Fort Worth, Texas 761930111, telephone (817) 2225122, fax (817) 222 5961.