AD 98-24-31

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 98-24-31, which was sent previously to all known U.S. owners and operators of BHTC Model 430 helicopters by individual letters. This AD requires, within 10 hours time-in-service (TIS), inspecting the lateral control tube (control tube) assembly and the forward fairing assembly for chafing. If chafing is found, replace the control tube assembly and rework the forward fairing assembly before further flight. If no chafing is found during the initial inspection, perform the corrective actions within the next 150 hours TIS. This amendment is prompted by two incidents of binding of the control tube assembly that occurred during flight. The actions specified by this AD are intended to prevent binding of the control tube assembly with the inside surface of the forward fairing assembly under certain load conditions and subsequent loss of control of the helicopter.

Final rule; request for comments

98-24-31 BELL HELICOPTER TEXTRON CANADA: Amendment 39-10998. Docket No. 98-SW-68-AD.

Applicability: Model 430 helicopters, serial numbers 49001 through 49018, 49020 through 49036, and 49038, certificated in any category.

NOTE 1: This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been 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 use the authority provided in paragraph (e) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition, or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed bythis AD. In no case does the presence of any modification, alteration, or repair remove any helicopter from the applicability of this AD.

Compliance: Required as indicated, unless accomplished previously.

To prevent binding of the lateral control tube (control tube) assembly with the inside surface of the forward fairing assembly under certain load conditions and subsequent loss of control of the helicopter, accomplish the following:

(a) Within 10 hours time-in-service (TIS), inspect for chafing between the inner surface of the forward fairing assembly, part number (P/N) 430-061-822-101, and the top surface of the control tube assembly, P/N 430-001-018-101.

(b) If any chafing is found, prior to further flight, replace the control tube assembly with an airworthy control tube assembly, P/N 430-001-018-113, and rework the forward fairing assembly, P/N 430-061-822-101. This reworking and replacing must be accomplished in accordance with Part II of the AccomplishmentInstructions of Bell Helicopter Textron Alert Service Bulletin No. 430-98-6, dated June 12, 1998 (ASB), except that contact with PSE is not required.

(c) If no chafing is found during the inspection in paragraph (a), within the next 150 hours TIS, replace the control tube assembly with an airworthy control tube assembly, P/N 430-001-018-113, and rework the forward fairing assembly in accordance with Part II of the Accomplishment Instructions of the ASB.

(d) Replacing the control tube assembly, P/N 430-001-018-101, with an airworthy control tube assembly, P/N 430-001-018-113, and reworking the forward fairing assembly as prescribed by this AD constitute terminating action for the requirements of this AD.

(e) 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, Rotorcraft 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, Rotorcraft Certification Office.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Rotorcraft Certification Office.

(f) 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.

(g) The replacing of the control tube assembly and the reworking of the forward fairing assembly shall be done in accordance with Bell Helicopter Textron Alert Service Bulletin No. 430-98-6, dated June 12, 1998. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Bell Helicopter Textron Canada, 12,800 Rue de l'Avenir, Mirabel, Quebec JON1LO,telephone (800) 463-3036, fax (514) 433-0272. Copies may be inspected at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

NOTE 3: The subject of this AD is addressed in Transport Canada (Canada) AD CF-98-29, dated August 31, 1998.

(h) This amendment becomes effective on February 3, 1999, to all persons except those persons to whom it was made immediately effective by Priority Letter AD 98-24-31, issued November 19, 1998, which contained the requirements of this amendment.

On November 19, 1998, the FAA issued priority letter AD 98-24-31, applicable to BHTC Model 430 helicopters, which requires, within 10 hours TIS, inspecting the control tube assembly and the forward fairing assembly for chafing. If chafing is found, the AD requires replacing the control tube assembly and reworking the forward fairing assembly before further flight. If no chafing is found during the initial inspection, the AD requires the corrective actions be accomplished within the next 150 hours TIS. Replacing the control tube assembly and reworking the forward fairing assembly as prescribed in this AD constitute terminating action for the requirements of this AD. That action was prompted by two incidents of binding of the control tube assembly that occurred during flight. This condition, if not corrected, could result in binding of the control tube assembly with the inside surface of the forward fairing assembly under certain load conditions and subsequent loss of control of the helicopter.

The FAA has reviewed Bell Helicopter Textron Alert Service Bulletin No. 430-98-6, dated June 12, 1998, which describes procedures for replacing the control tube assembly and reworking the forward fairing assembly. Additionally, Transport Canada, which is the Airworthiness Authority for Canada, has issued AD CF-98-29, dated August 31, 1998, to mandate these actions.

Since the unsafe condition described is likely to exist or develop on other BHTC Model 430 helicopters of the same type design, the FAA issued priority letter AD 98-24-31 to prevent binding of the control tube assembly with the inside surface of the forward fairing assembly under certain load conditions and subsequent loss of control of the helicopter. The AD requires, within 10 hours TIS, inspecting the control tube assembly, part number (P/N) 430-001-018-101, and the forward fairing assembly, P/N 430-061-822-101, for chafing between the inner surface of the forward fairing assembly and the top surface of the control tube assembly. If chafing is found, replacing the control tube assembly with an airworthy control tube assembly, P/N 430-001-018-113, and reworking the forward fairing assembly is required before further flight. If no chafing is found during the initial inspection, these corrective actions are required within the next 150 hours TIS. Replacing the control tube assembly and reworking the forward fairing assembly as prescribed in this AD constitute terminating action for the requirements of this AD. The actions are required to be accomplished in accordance with the service bulletin described previously. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the controllability of the helicopter. Therefore, inspecting the control tube assembly and the forward fairing assembly for chafing is required within 10 hours TIS, 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 November 19, 1998, to all known U.S. owners and operators of BHTC Model 430 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 12 helicopters of U.S. registry will be affected by this AD, that it will take approximately 12 work hours per helicopter to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $1,870 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $31,080, assuming the control tube assembly is replaced in the entire U.S. fleet.

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. 98-SW-68-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 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: