# AGENCY:

 Federal Aviation Administration, DOT. 

# ACTION:

 Final rule; request for comments. 

# SUMMARY:

                         This document publishes in the                         **Federal Register**                         an amendment adopting Emergency Priority Letter Airworthiness Directive (AD) 99-26-04, which was sent previously to all known U.S. owners and operators of Kaman Aerospace Corporation (Kaman) Model K1200 helicopters by individual letters. This AD requires, before the first flight of each day, inspecting for clutch assembly integrity. Replacing any unairworthy clutch assembly with an airworthy clutch assembly is required before further flight. This amendment is prompted by two incidents of engine adapter flange failure and loss of power to the main rotors. The actions specified by this AD are intended to prevent failure of the engine adapter flange, loss of power to the main rotors, and a subsequent forced landing.                     

# DATES:

 Effective February 8, 2000, to all persons except those persons to whom it was made immediately effective by Emergency Priority Letter AD 99-26-04, issued on December 8, 1999, which contained the requirements of this amendment. 

Comments for inclusion in the Rules Docket must be received on or before March 24, 2000. 

# ADDRESSES:

 Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 99-SW-72-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. 

# FOR FURTHER INFORMATION CONTACT:

 Wayne E. Gaulzetti, Aerospace Engineer, FAA, Boston Aircraft Certification Office, 12 New England Executive Park, Burlington, MA 01803, telephone (781) 238-7156, fax (781) 238-7199. 

# SUPPLEMENTARY INFORMATION:

 On December 8, 1999, the FAA issued Emergency Priority Letter AD 99-26-04, applicable to Kaman Model K1200 helicopters, which requires, before the first flight of each day, inspecting for clutch assembly integrity. Replacing any unairworthy clutch assembly with an airworthy clutch assembly is required before further flight. That action was prompted by two incidents of engine adapter flange failure and loss of power to the main rotors. One incident resulted in autorotation into trees with resulting loss of main rotor blades. The second incident resulted in a forced autorotation and damage to the nose landing gear. Subsequent investigation revealed that internal transmission clutch damage caused an engine adapter flange failure. This condition, if not corrected, could result in failure of the engine adapter flange, loss of power to the main rotors, and a subsequent forced landing. 

The FAA has reviewed Kaman K-1200 K-MAX Maintenance Manual Temporary Revision (TR) No. 284, dated November 5, 1999, which revises the procedures for engine area daily inspections and TR No. 289, dated November 12, 1999, which describes the method of inspecting the transmission assembly. 

Since the unsafe condition described is likely to exist or develop on other Kaman Model K1200 helicopters of the same type design, the FAA issued Emergency Priority Letter AD 99-26-04 to prevent failure of the engine adapter flange, loss of power to the main rotors, and a subsequent forced landing. The AD requires, before the first flight of each day, inspecting for clutch assembly integrity. Replacing any unairworthy clutch assembly with an airworthy clutch assembly is required before further flight. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the structural integrity of the helicopter. Therefore, inspecting for clutch assembly integrity before the first flight of each day and replacing any unairworthy clutch assembly is required prior to further flight, and this AD must be issued immediately. 

                    Since it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual letters issued on December 8, 1999 to all known U.S. owners and operators of Kaman Model K1200 helicopters. These conditions still exist, and the AD is hereby published in the                     **Federal Register**                     as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it effective to all persons.                 

The FAA estimates that 21 helicopters of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per helicopter to inspect the clutch assembly and 5 work hours per helicopter to replace the clutch assembly, if necessary. The average labor rate is $60 per work hour. Required parts, if replacement of a clutch assembly is necessary, will cost approximately $16,000 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $459,500 per year, assuming 300 clutch assembly inspections, per helicopter, per year, and replacement of 5 unairworthy clutch assemblies. 

## 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                     Start Printed Page 3584                    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 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. 99-SW-72-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 

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

**AD 99-26-04 Kaman Aerospace Corporation:**                        Amendment 39-11523. Docket No. 99-SW-72-AD.                     

Applicability: Model K-1200 helicopters, with clutch assembly, part number (P/N) K974002-701, 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 include specific proposed actions to address it. 

*Compliance:*                        Required before the first flight of each day.                     

To prevent failure of the engine adapter flange, loss of power to the main rotors, and a subsequent forced landing, accomplish the following: 

(a) Inspect the integrity of the clutch assembly, in a location where background noise would not hinder evaluation, by firmly and uniformly rotating the Kaflex shaft in the anti-rotating direction (counter-clockwise looking forward) while maintaining hand contact. The anti-rotation speed should be approximately one-fourth to one-half revolution per second. An unairworthy clutch will feel rough with a continuous dry “raspy” feel and sound, or it may feel as though the clutch has heavy detents or “catches” on the interior surface that impede the free rotary motion. 

(b) Remove any unairworthy clutch assembly, P/N K974002-701, before further flight and replace with an airworthy clutch assembly. 

# Note 2: 

Kaman K-1200 K-MAX Maintenance Manual Temporary Revision (TR) No. 284, dated November 5, 1999, which revises the procedures for engine area daily inspections and TR No. 289, dated November 12, 1999, which describes the method of inspecting the transmission assembly, pertain to the subject of this AD. 

(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 3: 

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. 

(e) This amendment becomes effective on February 8, 2000, to all persons except those persons to whom it was made immediately effective by Emergency Priority Letter AD 99-26-04, issued December 8, 1999, which contained the requirements of this amendment. 

Issued in Fort Worth, Texas, on January 13, 2000. 

Eric Bries, 

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service. 

[FR Doc. 00-1642 Filed 1-21-00; 8:45 am] 

BILLING CODE 4910-13-U