Transport Canada, which is the airworthiness authority for Canada, has notified the FAA that an unsafe condition may exist on BHTC Model 430 helicopters. Transport Canada advises that, in one instance, loss of torque on the bolts resulted in fracture of four of the eight bolts and a loose vertical fin on a Model 230 helicopter which is of similar design to the Model 430 series helicopters.
BHTC has issued Bell Helicopter Textron Alert Service Bulletin No. 430-98-5, dated June 12, 1998 (ASB), which specifies a bolt torque check within 25 hours after receipt of the ASB; removal, inspection, and installation of the tailboom and vertical fin modification with attaching hardware replacement at the next scheduled 150-hour inspection after receipt of the ASB; and verifying the bolt torque within 5 to 10 hours after each fin removal and installation, and at every 150 hours of operation. Transport Canada classified this ASB as mandatory and issued AD CF-98-23, dated August 7, 1998, in order to assure the continued airworthiness of these helicopters in Canada.
This helicopter model is manufactured in Canada and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, Transport Canada has kept the FAA informed of the situation described above. The FAA has examined the findings of Transport Canada, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.
Since an unsafe condition has been identified that is likely to exist or develop on other BHTC Model 430 helicopters of the same type design registered in the United States, this AD is being issued to prevent loss of torque of the bolts, which could lead to fracture of the bolts, separation of the vertical fin from the helicopter, and subsequent loss of control of the helicopter.
This AD requires verifying the bolt torque within 25 hours time-in-service (TIS); modifying the vertical fin and tailboom fittings and replacing the attachment hardware at or before the next 150-hour TIS inspection; and re-verifying the torque on the bolts within 10 hours TIS after inspecting the vertical fin. The actions are required to be accomplished in accordance with the bulletin described previously. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the structural integrity of the helicopter. Therefore, verifying the torque is required within 25 hours time-in-service (TIS), 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 areimpracticable, and that good cause exists for making this amendment effective in less than 30 days.
Cost Impact
The FAA estimates that 14 helicopters will be affected by this AD, that it will take approximately 3 work hours to accomplish the initial torque verifications and vertical fin inspection, 12 work hours to modify the vertical fin and install the attachment hardware, 1 work hour to accomplish the repetitive torque verification after the modification, and 1 work hour to accomplish each 150-hour inspection, and that the average labor rate is $60 per work hour. Required parts will cost approximately $1,692 if the CA430-98-5-2 kit is used or $2,399 if the CA430-98-05-1 kit is used. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $47,866, assuming only the CA430-98-05-1 kit is installed and one repetitive 150-hour inspection on each helicopter.
Comments Invited
Although this action is in the form of a final rulethat 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. 98-SW-50-AD." The postcard will be date stamped and returned to the commenter.
Regulatory Impact
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 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: