AD 98-24-35 SUPERSEDED

This amendment adopts a new airworthiness directive (AD) that is applicable to Eurocopter France Model AS-350B, B1, B2, BA, C, D, D1, and AS 355E, F, F1, F2, and N helicopters. This action requires measuring the tail rotor pitch change control rod (control rod) outboard spherical bearing for radial and axial play. If the play exceeds 0.008-inch, replacing the control rod with an airworthy control rod is required. This amendment is prompted by one accident and one incident. Investigations revealed a broken control rod on the helicopter involved in the accident and a severely worn control rod on the helicopter involved in the incident. This condition, if not corrected, could result in separation of the outboard spherical bearing ball from its outer race, rubbing of the body of the control rod against the tail rotor blade pitch horn clevis, failure of the control rod, and loss of control of the helicopter.

Final rule; request for comments

98-24-35 EUROCOPTER FRANCE: Amendment 39-10921. Docket No. 98-SW-41-AD.
Applicability: Eurocopter France Model AS-350B, B1, B2, BA, C, D, D1, and AS 355E, F, F1, F2, and N helicopters, with tail rotor pitch change control rod (control rod), part number (P/N) 350A33-2145-01, 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 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 (b) 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 includean assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any helicopter from the applicability of this AD.

Compliance: Required within 50 hours time-in-service (TIS) after the effective date of this AD, unless accomplished previously, and thereafter at intervals not to exceed 50 hours TIS.

To prevent separation of the outboard spherical bearing ball from its outer race, rubbing of the body of the control rod against the tail rotor blade pitch horn clevis, failure of the control rod, and loss of control of the helicopter, accomplish the following:

(a) Using a dial indicator, measure the axial and radial play of the outboard spherical bearing on the control rod. If the play exceeds 0.008-inch, replace the control rod with an airworthy control rod.

(b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used when approved by the Manager, Rotorcraft Standards Staff, Rotorcraft Directorate, 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 Standards Staff.

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

(c) 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.

(d) This amendment becomes effective on December 17, 1998.

This amendment was prompted by an accident, which occurred in November 1996, and an incident, which occurred in August 1997, involving Model AS-350B2 helicopters offshore over the Gulf of Mexico. The DGAC, although notified by the FAA of both the accident and incident, has not issued an AD on this subject. There were two other unconfirmed incidents cited by the National Transportation Safety Board (based on manufacturer's reports) involving the same control rod, part number (P/N) 350A33-2145-01.

These helicopter models are manufactured in France and are 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. The FAA has determined that AD action is necessary for products of this type design certified for operation in the United States.

Since an unsafe condition has been identified that is likely to existor develop on other Eurocopter France Model AS-350B, B1, B2, BA, C, D, D1, and AS 355E, F, F1, F2, and N helicopters of the same type design registered in the United States, this AD is being issued to prevent separation of the outboard spherical bearing ball from its outer race, rubbing of the body of the control rod against the tail rotor blade pitch horn clevis, failure of the control rod, and loss of control of the helicopter. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the controllability of the helicopter. Therefore, measuring the control rod outboard spherical bearing radial and axial play is required within 50 hours time-in-service, 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 are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

Cost Impact
The FAA estimates that 507 helicopters will be affected by this AD, that it will take approximately 1 work hour, and that the average labor rate is $60 per work hour. Required parts will cost approximately $2,376 per helicopter. Based on these figures, the total cost impact of this AD on U.S. operators is estimated to be $1,235,052 to perform the measurement and to replace both control rods on each helicopter in the 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-41-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, 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:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional
Counsel, Southwest Region, Attention: Rules Docket No. 98-SW-41-AD, 2601 Meacham Blvd., Room 663, Fort Worth,
Texas 76137.

Mr. Shep Blackman, Aerospace Engineer, FAA, Rotorcraft Directorate,
Rotorcraft Standards Staff, 2601 Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5296, fax
(817) 222-5961.