On March 4, 1993, the FAA issued Priority Letter AD 93-03-01, to require an initial and repetitive visual inspections of the clutch control spring assembly (assembly) for component wear and security, and replacement of affected unairworthy parts. That action was prompted by an accident involving a Schweizer Aircraft Corporation Model 269C helicopter. Reportedly, the helicopter lost engine drive power and was unsuccessful in performing a forced landing from 100 feet above ground level (AGL). A subsequent investigation revealed that the assembly had failed, and that the aluminum spring retainer, part number (P/N) 269A5483-7, of the failed assembly had excessive wear. That condition, if not corrected, could result in failure of the aluminum spring retainer, loss of power to the rotor drive system, and a subsequent forced landing.
Since the issuance of that AD, the manufacturer has issued a revised service bulletin, Schweizer Service Bulletin (SB)B-256.2, dated June 11, 1993, that describes procedures for an initial and repetitive inspections for component wear of the assembly in greater detail than the previously-issued service bulletin, and describes procedures for further inspections if disassembly is necessary. It also describes procedures for replacement of the aluminum spring retainer, P/N 269A5452, P/N 269A5452-3, P/N 269A5452-5, or P/N 269A5483-7, and the plastic sleeve, P/N 269A5590-101, which was not described in SB B-256.1, dated January 20, 1993, the SB cited in AD 93-03-01.
Since an unsafe condition has been identified that is likely to exist or develop on other Schweizer Aircraft Corporation and Hughes Helicopters, Inc. Model 269A, 269A-1, 269B, 269C, and TH-55A helicopters of the same type design, this AD supersedes AD 93-03-01 to require an initial and repetitive visual inspections of the assembly for component wear; and, if any worn or unairworthy parts are found, disassembly, further inspections, and replacement of any unairworthy parts. The actions are required to be accomplished in accordance with SB B-256.2, dated June 11, 1993, described previously. The assembly puts tension on the belt drive between the transmission and the main rotor. If the assembly fails and there is no tension on the belt, the transmission will not turn the main rotor. Due to the criticalness of the clutch control assembly, and a short compliance time, this rule must be issued immediately to correct an unsafe condition in aircraft.
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.
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 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. 94-SW-15-AD." The postcard will be date stamped and returned to the commenter.
The regulations adopted herein will not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.
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, Incorporation by reference, 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 citationfor part 39 continues to read as follows:
Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89.
39.13 - [Amended]
2. Section 39.13 is amended by adding a new airworthiness directive (AD), Amendment 39-9148, to read as follows: