01-5170. Airworthiness Directives; Kaman Aerospace Corporation Model K-1200 Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) for Kaman Aerospace Corporation (Kaman) Model K-1200 helicopters. The AD would require reducing the life limit of the rotor shaft and teeter pin assembly, and establishing a life limit for the flap clevis. This proposal is prompted by the discovery of cracks in parts that were returned to the manufacturer. The actions specified by the proposed AD are intended to prevent failure of the rotor shaft, teeter pin assembly, or flap clevis due to fatigue cracks, and subsequent loss of control of the helicopter.

DATES:

Comments must be received on or before May 4, 2001.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2000-SW-50-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. You may also send comments electronically to the Rules Docket at the following address: [e-mail]. 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.

FOR FURTHER INFORMATION CONTACT:

Richard Noll, Aviation Safety Engineer, Boston Aircraft Certification Office, 12 New England Executive Park, Burlington, MA 01803, telephone [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

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, specified above, 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. 2000-SW-50-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. 2000-SW-50-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

Discussion

This document proposes the adoption of a new airworthiness directive (AD) for Kaman Model K-1200 helicopters. The AD would require:

• Reducing the life limit for the rotor shaft from 10,000 hours time-in-service (TIS) to 3,750 TIS;
• Reducing the life limit of the teeter pin assembly from 10,000 hours TIS to 550 hours TIS; and
• Establishing a life limit of the flap clevis of 640 hours TIS.

This proposal is prompted by the discovery of cracks in parts that were returned to the manufacturer. The actions specified by the proposed AD are intended to prevent failure of the rotor shaft, teeter pin assembly, or flap clevis due to fatigue cracks, and subsequent loss of control of the helicopter.

Since an unsafe condition has been identified that is likely to exist or develop on other Kaman Model K-1200 helicopters of the same type design, the proposed AD would require:

• Reducing the life limit of the rotor shaft, part number (P/N) K974112-001, -003, -005, -007, -009, or -101, from 10,000 hours TIS to 3,750 hours TIS;
• Reducing the life limit of the teeter pin assembly, P/N K910005-007 or -009, from 10,000 hours to 550 hours TIS; and
• Establishing a life limit of the flap clevis, P/N K911049-011, -017, -019, or -021, of 640 hours TIS.

The FAA estimates that 9 helicopters of U.S. registry would be affected by this proposed AD, that it would take 0.25 hour per helicopter to accomplish the proposed changes to the Limitations section of the applicable maintenance manual, and that the average labor rate is $60 per work hour. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $135, plus an increase in hourly operating costs of approximately $13 for each affected helicopter.

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 under 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.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

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:

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:

Kaman Aerospace Corporation: Docket No. 2000-SW-50-AD.

Applicability: Model K-1200 helicopters, 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 include specific proposed actions to address it.

Compliance: Required within 25 hours time-in-service, unless accomplished previously.

To prevent failure of the rotor shaft, teeter pin assembly, or flap clevis due to fatigue cracks, and subsequent loss of control of the helicopter, accomplish the following:

(a) Remove any rotor shaft, part number (P/N) K974112-001, -003, -005, -007, -009, or -101, that has 3,750 or more hours time-in-service (TIS) and replace it with an airworthy rotor shaft. Remove any teeter pin assembly, P/N K910005-007 or -009, that has 550 or more hours TIS and replace it with an airworthy teeter pin assembly. Remove any flap clevis, P/N K911049-011, -017, -019, or -021, that has 640 or more hours TIS and replace it with an airworthy flap clevis.

(b) This AD revises the Limitations section of the maintenance manual by reducing the life limit of the rotor shaft, P/N K974112-001, 003, -005, -007, -009, and -001, to 3,740 hours TIS; reducing the life limit of the teeter pin assembly, P/N K910005-007 and -009, to 550 hours TIS; and establishing a life limit for the flap clevis, P/N K911049-011, -017, -019, and -021, of 640 hours TIS.

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

Note 2:

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

(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.

Issued in Fort Worth, Texas, on February 21, 2001.

Eric Bries,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.