AD 2001-02-11 ACTIVE

This amendment adopts a new airworthiness directive (AD) for Bell Helicopter Textron, Inc. (BHTI) Model 204B helicopters that requires replacing any main rotor mast assembly (mast), part number (P/N) 204-011-450-001, within 25 hours time-in-service (TIS). This amendment is prompted by the crash of a restricted category Model UH-1B helicopter due to failure of a mast, P/N 204-011-450-001. The same mast P/N is used on the Model 204B helicopters. The actions specified by this AD are intended to prevent failure of the mast and subsequent loss of control of the helicopter.

Final rule

2001-02-11 BELL HELICOPTER TEXTRON, INC.: Amendment 39-12096. Docket No. 2000- SW-16-AD.
Applicability: Model 204B helicopters with main rotor mast assembly, part number (P/N) 204- 011-450-001, 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 (b) 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 include specific proposed actions to address it.Compliance: Required within 25 hours time-in-service, unless accomplished previously.

To prevent failure of the main rotor mast assembly (mast) and subsequent loss of control of the helicopter, accomplish the following:

(a) Remove any mast, P/N 204-011-450-001, from service and replace it with an airworthy mast. Accomplishing the requirement of this paragraph constitutes terminating action for the requirements of this AD. P/N 204-011-450-001 is not eligible for installation on any helicopter.

(b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Rotorcraft Certification Office, 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, Rotorcraft Certification Office.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Rotorcraft Certification Office.

(c) 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.

(d) This amendment becomes effective on March 22, 2001.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD for BHTI Model 204B helicopters was published in the Federal Register on October 2, 2000 (65 FR 58681). That action proposed replacing any mast, P/N 204-011-450-001, within 25 hours TIS.

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.

The FAA estimates that 15 helicopters of U.S. registry will be affected by this AD, that it will take approximately 10 work hours per helicopter to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $8,862 per helicopter. Based on these figures, the total
cost impact of the AD on U.S. operators is estimated to be $141,930

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 FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas.

List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.

Michael Kohner, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Rotorcraft Certification Office, Fort Worth, Texas 76193-0170, telephone (817) 222-5447, fax (817) 222-5783.