AD 2000-18-10

This amendment adopts a new airworthiness directive (AD) for Kaman Model K-1200 helicopters. This action requires replacing certain unairworthy sprag clutches with airworthy sprag clutches. This amendment is prompted by two incidents of sprag clutch failure during external load operations. The actions specified in this AD are intended to prevent a malfunctioning transmission clutch, loss of drive to the main rotor system, and subsequent loss of control of the helicopter.

Final rule; request for comments

2000-18-10 KAMAN AEROSPACE CORPORATION: Amendment 39-11895. Docket No. 2000-SW-32- AD.
Applicability: Model K-1200 helicopters, with sprag clutch, part number (P/N) K974110-005, 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 10 hours time-in-service, unless accomplished previously.

To prevent a malfunctioning transmission clutch, loss of drive to the main rotor system, and subsequent loss of control of the helicopter, accomplish the following:

(a) Replace each sprag clutch, P/N K974110-005, with a sprag clutch, P/N K974110-003. Sprag clutch, P/N K974110-005, is considered unairworthy.

NOTE 2: Kaman Aerospace Corporation Service Bulletin No. 090, dated July 13, 2000, pertains to the subject of this AD.

(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, 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.

(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, without an external load, to a location where the requirements of this AD can be accomplished.

(d) This amendment becomes effective on September 26, 2000.

This amendment adopts a new AD for Kaman Model K-1200 helicopters. This action requires replacing any sprag clutch, part number (P/N) K974110-005, with P/N K974110-003. This amendment is prompted by two incidents of sprag clutch, P/N K974110-005, failure during external load operations. The actions specified in this AD are intended to prevent a malfunctioning transmission clutch. This condition, if not corrected, could result in loss of drive to the main rotor system, and subsequent loss of control of the helicopter.

The FAA has reviewed Kaman Aerospace Corporation Service Bulletin No. 090, dated July 13, 2000, which describes procedures for removing the sprag clutch, P/N K974110-005.

We have identified an unsafe condition that is likely to exist or develop on other Kaman Model K-1200 helicopters of the same type design. This AD is being issued to prevent a malfunctioning transmission clutch, loss of drive to the main rotor system, and subsequent loss of control of the helicopter. This AD requires replacing any sprag clutch, P/N K974110-005, with P/N K974110-003. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the delivery of power to the main rotor system of the helicopter. Therefore, replacing any sprag clutch, P/N K974110-005, with P/N K974110-003 is required within 10 hours time-in-service, and this AD must be issued immediately.

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

The FAA estimates that 4 helicopters will be affected by this AD, that it will take approximately 4 work hours to replace the sprag clutch, and that the average labor rate is $60 per work hour. Required parts will cost approximately $17,000 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $68,960.

Comments Invited
Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this 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 under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the 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 that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their mailed comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket No. 2000-SW-32-AD." The postcard will be date stamped and returned to the commenter.

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.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, 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, 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.

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