AD 2009-15-15

We are adopting a new airworthiness directive (AD) for Bell Helicopter Textron Canada (BHTC) Model 427 helicopters. This AD results from mandatory continuing airworthiness information (MCAI) originated by the aviation authority of Canada to identify and correct an unsafe condition on an aviation product. Transport Canada, the aviation authority of Canada, with which we have a bilateral agreement, states that it has been determined that the existing hardware connecting the vertical fin to the tail rotor gearbox needs 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 clamp-up. If not corrected, the vertical fin could become loose and cause vibration, which could lead to subsequent loss of control of the helicopter. This AD requires actions that are intended to address this unsafe condition.

Final rule.

2009-15-15 Bell Helicopter Textron Canada (BHTC): Amendment 39- 15978; Docket No. FAA-2009-0227; Directorate Identifier 2007-SW-65- AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective on September 8, 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 needs 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 clamp-up. 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 time-in-service, 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 AD

(h) This AD differs from the MCAI AD 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 time-in-service'' 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, 2601 Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5122, fax (817) 222-5961.

Related Information

(j) Mandatory Continuing Airworthiness Information (MCAI) Transport Canada Airworthiness Directive CF-2007-22, dated September 14, 2007, and Bell Helicopter Textron Alert Service Bulletin No. 427-06-15, dated December 14, 2006, contain related information.

Subject

(k) Joint Aircraft System/Component (JASC) Code: 5553, Vertical Stabilizer, Attach Fittings.

Discussion

We issued an NPRM to amend 14 CFR part 39 to include an AD that would apply to BHTC Model 427 helicopters on March 4, 2009. That NPRM was published in the Federal Register on March 23, 2009 (74 FR 12098). That NPRM proposed to require actions to prevent the vertical fin from becoming loose and causing vibration, which could lead to subsequent loss of control of the helicopter. 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. 427- 06-15, dated December 14, 2006. 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 AD

We have reviewed the MCAI AD and related service information and, in general, agree with their substance. This AD differs from the MCAI AD as follows:
We do not require compliance "no later than November 27, 2007'', because that date has passed.
We refer to the compliance time as "hours time-in- service'' rather than "air time hours.''
These differences are highlighted in the "Differences Between this AD and the MCAI AD'' section in the AD.

Costs of Compliance

We estimate that this AD will affect about 17 products of U.S. registry. We also estimate that it will take about 2 work-hours per helicopter to remove and visually inspect the vertical fin and the tail rotor gearbox attachment legs and to re-install the vertical fin. The average labor rate is $80 per work-hour. Required parts will cost about $227 per helicopter. Based on these figures, we estimate the cost of this 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 product(s) 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 inthe AD docket.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, 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: