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Proposed Rule

Airworthiness Directives; MD Helicopters, Inc., Model MD900 Helicopters

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Federal Aviation Administration, DOT.


Notice of proposed rulemaking (NPRM).


This document proposes adopting a new airworthiness directive (AD) for certain serial numbered MD Helicopters, Inc. (MDHI) Model MD900 helicopters. The AD would require, for the lateral-mixer bellcrank assembly (bellcrank), establishing a life limit, creating a component history card or equivalent record, determining the hours time-in-service (TIS), and applying a serial number (S/N). This proposal is prompted by additional testing, which revealed that the original load test to establish the life limits of the bellcrank did not accurately represent the actual loading. The actions specified by the proposed AD are intended to prevent fatigue failure of the bellcrank and subsequent loss of lateral control of the helicopter.


Comments must be received on or before March 18, 2002.


Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2001-SW-25-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. You may also send comments electronically to the Rules Docket at the following address: Comments may be inspected at the Office of the Regional Counsel between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays.

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Jon Mowery, Aviation Safety Engineer, FAA, Los Angeles Aircraft Certification Office, Airframe Branch, 3960 Paramount Blvd., Lakewood, California 90712, telephone (562) 627-5322, fax (562) 627-5210.

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Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments will be considered before taking action on the proposed rule. The proposals contained in this document may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their mailed comments submitted in response to this proposal must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket No. 2001-SW-25-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2001-SW-25-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.


This amendment proposes adopting a new AD for certain serial numbered MDHI Model MD900 helicopters with a bellcrank, P/N 900C2010203-105, installed that currently has an unlimited life. Additional testing has revealed that the original load test to establish the life limits of the part did not accurately represent the actual loading. Thus, we have determined that the bellcrank should have a serviceable life of 13,300 hours TIS. This creates an unsafe condition. This condition, if not corrected, could result in fatigue failure of the bellcrank and subsequent loss of lateral control of the helicopter.

This unsafe condition is likely to exist or develop on certain other helicopters of the same type design. Therefore, the proposed AD would require, before further flight, the following for the bellcrank on an affected helicopter:

  • Create a component history card or equivalent record.
  • Determine the hours TIS of the bellcrank.
  • Apply a S/N.
  • Remove any affected bellcrank that exceeds the life limit.

This AD would revise the Limitations section of the maintenance manual by establishing a life limit of 13,300 hours TIS for the bellcrank, P/N 900C2010203-105.

The FAA estimates that 30 helicopters of U.S. registry would be affected by this proposed AD, that it would take approximately 1/2 work hour per helicopter to accomplish the required actions for the bellcrank, and that the average labor rate is $60 per work hour. Required parts would cost approximately $10,120 per helicopter. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $304,500 assuming replacement of the bellcranks in all 30 helicopters.

The regulations proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that 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) if promulgated, will not have a significant economic impact, positive or negative, on a substantial number of small entities Start Printed Page 2146under the criteria of the Regulatory Flexibility Act. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

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List of Subjects in 14 CFR Part 39

  • Air transportation
  • Aircraft
  • Aviation safety
  • Safety
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The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

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1. The authority citation for part 39 continues to read as follows:

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Authority: 49 U.S.C. 106(g), 40113, 44701.

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

MD Helicopters, Inc.: Docket No. 2001-SW-25-AD.

Applicability: Model MD900 helicopters, Serial Number (S/N) 900-00008, 900-00010 through 900-00098, and 900-00100, with a lateral-mixer bellcrank assembly (bellcrank), part number (P/N) 900C2010203-105, 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 (e) 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: Before further flight, unless accomplished previously.

To prevent fatigue failure of the bellcrank and subsequent loss of lateral control of the helicopter, accomplish the following:

(a) Create a component history card or equivalent record for each bellcrank and record the hours time-in-service (TIS) of the bellcrank. If the hours TIS of the bellcrank cannot be determined, use the helicopter's total hours TIS as the hours TIS for the bellcrank.

(b) Apply a S/N to the bellcrank in accordance with the Accomplishment Instructions, paragraph (1)(a) and (1)(b), of MD Helicopters, Inc. Service Bulletin SB 900-084, dated December 3, 2001.

(c) Remove any bellcrank that has exceeded 13,300 hours TIS.

(d) This AD revises the Limitations section of the maintenance manual by establishing a life limit of 13,300 hours TIS for bellcrank, P/N 900C2010203-105.

(e) 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, Los Angeles Aircraft Certification Office (LAACO), FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, LAACO.

Note 2:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the LAACO.

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

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Issued in Fort Worth, Texas, on January 4, 2002.

David A. Downey,

Manager, Rotorcraft Directorate, Aircraft Certification Service.

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[FR Doc. 02-1058 Filed 1-15-02; 8:45 am]