AD 2003-04-12

This amendment adopts a new airworthiness directive (AD) for the specified Bell Helicopter Textron Canada (Bell) model helicopters that requires modifying the auxiliary fin assemblies and revising the Limitations section of the Rotorcraft Flight Manual (RFM) to reduce the never-exceed speed (Vne) for a tail rotor pedal stop failure. This amendment is prompted by several incidents of main rotor blades contacting the top of the fin that have resulted in an upper tuning weight (weight) becoming loose. The actions specified by this AD are intended to prevent a main rotor blade from striking an auxiliary fin, loss of a tuning weight, impact with a tail or main rotor blade, and subsequent loss of control of the helicopter.

Final rule.

2003-04-12 Bell Helicopter Textron Canada: Amendment 39-13061. Docket No. 2001-SW-43-AD.

Applicability: Model 427 helicopters, serial numbers 56001 through 56030 with auxiliary fin assemblies, part numbers 427-035-836-101, -102, -105, or -106, installed, certificated in any category.

Note 1: This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and if the unsafe condition has not been eliminated, the request should includespecific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent a main rotor blade from striking an auxiliary fin, loss of an upper tuning weight, impact with a tail or main rotor blade, and subsequent loss of control of the helicopter:

(a) Within 60 days, modify auxiliary fin assemblies, part numbers (P/N) 427-035-836-101, -102, -105, or -106, in accordance with the Accomplishment Instructions in Bell Helicopter Textron Alert Service Bulletin No. 427-01-07, dated November 16, 2001.

(b) After accomplishing paragraph (a) of this AD, reduce the never-exceed speed (Vne) limitation for a pedal stop failure from 80 knots indicated airspeed (KIAS) to 60 KIAS.

Note 2: Bell Helicopter Textron Rotorcraft Flight Manual BHT-427-FM-2, Revision 5, dated April 23, 2002, incorporates the reduced airspeed limitation for a pedal stop failure.

(c) An alternative method of compliance or adjustment of the compliance timethat provides an acceptable level of safety may be used if approved by the Manager, Regulations Group, Rotorcraft Directorate, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Regulations Group.

Note 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Regulations Group.

(d) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the helicopter to a location where the requirements of this AD can be accomplished.

(e) The modification shall be done in accordance with the Accomplishment Instructions in Bell Helicopter Textron Alert Service Bulletin No. 427-01-07, dated November 16, 2001. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Bell Helicopter Textron Canada, 12,800 Rue de l'Avenir, Mirabel, Quebec J7J1R4, telephone (450) 437-2862 or (800) 363-8023, fax (450) 433-0272. Copies may be inspected at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(f) This amendment becomes effective on April 4, 2003.

Note 4: The subject of this AD is addressed in Transport Canada (Canada) AD No. CF-2001-05R1, dated February 13, 2002.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to add an AD for Bell Model 427 helicopters was published in the Federal Register on November 28, 2001 (66 FR 59377). That NPRM would have required modifying the fins, part number (P/N) 427-035-836-101 and 427-035-836-102, to relocate the weights, P/N 407-023-003-145. That proposal recognized that relocating the tuning weights was an interim action and anticipated that contact between the main rotor blades and the top portion of the fins would be addressed in a separate AD. However, prior to publishing the final rule based on that NPRM, the manufacturer published service information about reducing the height of the fins. Further, Transport Canada issued a revised AD requiring the height reduction in Canada. Hence, reducing the height of the fins made the relocation of the tuning weights unnecessary, therefore a supplemental proposal was published in the Federal Register on October 18, 2002 (67 FR 64326). That action proposed to require modifying the auxiliary fin assemblies to reduce the height and revising the Limitations section of the RFM to reduce the Vne for a tail rotor pedal stop failure from 80 knots indicated airspeed (KIAS) to 60 KIAS.

Transport Canada, the airworthiness authority for Canada, notified the FAA that an unsafe condition may exist on Bell Model 427 helicopters. Transport Canada advises of several ground incidents of main rotor blades contacting the top portion of a fin. Such incidents occurred on helicopters with an internal gross weight capability of 6,350 lbs. and the larger auxiliary fin assemblies.

Bell has issued Alert Service Bulletin 427-01-7, dated November 16, 2001 (ASB), which specifies reducing the height of the auxiliary fin assembly, part number (P/N) 427-035-836-101, -102, -105, and -106 within 300 hours time-in-service (TIS). Transport Canada classified this ASB as mandatory and issued AD No. CF-2001-05R1, datedFebruary 13, 2002, to ensure the continued airworthiness of these helicopters in Canada.

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposal or the FAA's determination of the cost to the public. The FAA has determined that air safety and the public interest require the adoption of the rule as proposed with the exception of minor non-substantive changes and updating the Rotorcraft Flight Manual from Revision 3 to Revision 5, which is referenced in Note 2 of the AD.

The FAA estimates that 30 helicopters of U.S. registry will be affected by this AD, that it will take approximately 12 work hours per helicopter to accomplish the actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $1,685 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $72,150 to perform the modifications and revisions for the entire fleet.

The regulations adopted herein 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, it is determined that this final rule does not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under 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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment

Accordingly, pursuant to 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

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. Section 39.13 is amended by adding a new airworthiness directive to read as follows: