01-8620. Airworthiness Directives; Eurocopter France Model AS350B, B1, B2, B3, BA, C, D, D1, and AS355E, F, F1, F2, and N Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes superseding an existing airworthiness directive (AD) for Eurocopter France Model AS350B, B1, B2, BA, C, D, D1, and AS355E, F, F1, F2, and N helicopters. That AD currently requires measuring the tail rotor pitch control rod (control rod) outboard spherical bearing (bearing) for radial and axial play and replacing the control rod with an airworthy control rod if the play exceeds 0.008-inch. This action would retain those requirements but would add the Eurocopter France Model AS350B3 helicopter and an additional control rod to the applicability. This action would also add a daily inspection of the control rod and an axial play limit of 0.016-inch and would revise the AD compliance interval from 50 hours time-in-service (TIS) to 30 hours TIS. This proposal is prompted by two comments received on AD 98-24-35 and the determination that the AD inspection interval should coincide with the normal maintenance interval and the AD should apply to the Eurocopter France Model AS350B3 helicopter. The actions specified by the proposed AD are intended to prevent separation of the 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.

DATES:

Comments must be received on or before June 8, 2001.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2000-SW-12-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. You may also email comments to the Rules Docket at [e-mail].

FOR FURTHER INFORMATION CONTACT:

Uday Garadi, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Regulations Group, Fort Worth, Texas 76193-0111, telephone [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed 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 above. All communications received on or before the closing date for comments will be considered before taking action on the proposed rule. The proposals contained in this document may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their mailed comments submitted in response to this proposal must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket No. 2000-SW-12-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2000-SW-12-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

Discussion

On November 19, 1998, the FAA issued AD 98-24-35, Amendment 39-10921 (63 FR 66418, December 2, 1998), to require measuring the control rod bearing radial and axial play within 50 hours TIS and thereafter at intervals not to exceed 50 hours TIS. That action was prompted by an accident and an incident involving Eurocopter France Model AS350B2 helicopters offshore over the Gulf of Mexico. 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. The requirements of that AD are intended to prevent separation of the 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.

Since the issuance of that AD, Eurocopter France has issued Service Letter No. 1367-64-98, dated January 12, 1999. The service letter provides operators with a more accurate way to determine the looseness of the bearing by adding an axial play limit of 0.016 inch and a daily inspection. Also, the FAA received comments to AD 98-24-35 from two commenters, the manufacturer and an operator. The commenters state that a larger axial play limit and a 30-hour visual check would provide a satisfactory degree of safety for this control rod and an adequate inspection interval. The FAA agrees, and this action would add a daily inspection of the control rod and an axial play limit of 0.016-inch and would revise the AD compliance interval from 50 hours TIS to 30 hours TIS.

Since an unsafe condition has been identified that is likely to exist or develop on other helicopters of these same type designs, the proposed AD would supersede AD 98-24-35 to retain the same requirements and would add the following requirements:

• Add the Eurocopter France Model AS350B3 helicopter to the applicability.
• Add control rod, P/N 350A33-3145-00, to the applicability.
• Revise the AD inspection interval so that it does not exceed 30 hours TIS to coincide with the normal maintenance interval.
• Establish a daily inspection of the tail rotor pitch control rod bearing for axial play.
• Establish an axial play limit of 0.016-inch.

The FAA estimates that 610 helicopters of U.S. registry would be affected by this proposed AD, that it would take approximately 1 work hour per helicopter to accomplish the proposed actions, and that the average labor rate is $60 per work hour. Required parts would cost approximately $1,224 for two control rods per helicopter. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $783,240.

The regulations proposed herein would 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 proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this proposed regulation (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting 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

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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 removing Amendment 39-10921 (63 FR 66418, December 2, 1998), and by adding a new airworthiness directive (AD), to read as follows:

Eurocopter France: Docket No. 2000-SW-12-AD. Supersedes AD 98-24-35 Amendment 39-10921, Docket No. 98-SW-41-AD.

Applicability: Eurocopter France Model AS350B, B1, B2, B3, BA, C, D, D1, and AS355E, F, F1, F2, and N helicopters, with tail rotor pitch control rod (control rod), part number (P/N) 350A33-2145-01 or P/N 350A33-3145-00, 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 request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. This 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 as indicated, unless accomplished previously.

To prevent separation of the outboard spherical bearing (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) Before the first flight of each day, configure the helicopter by ensuring the tail rotor pedals are in neutral position. If the helicopter is fitted with a tail rotor load compensator, discharge the accumulator as described in the flight manual. Inspect the bearing for play (Figure 1) on the helicopter, by observation and feel, by slightly moving the tail rotor blade in the flapping axis while monitoring the bearing for movement.

(1) If the Teflon cloth is found to be coming out of its normal position within the bearing, totally or partially, replace the control rod with an airworthy control rod before further flight.

(2) If play is detected, measure the bearing wear using a dial indicator as shown in Figure 2. Perform the following steps (Figure 2) unless they were accomplished within the last 30 hours TIS.

(i) Remove the control rod.

(ii) Install a bolt, washers, and a nut to secure the bearing.

(iii) Mount the bearing in a vise as shown in Figure 2.

(iv) Using a dial indicator, take two radial measurements in the areas shown by the two arrows.

(v) Take axial measurements in the area shown by an arrow.

(vi) Record the hours of operation on each control rod.

(vii) If the radial play exceeds 0.008 inch or axial play exceeds 0.016 inch, replace the control rod with an airworthy control rod before further flight.

(3) If the radial and axial play are within limits, reinstall the control rod.

(4) At intervals not to exceed 30 hours TIS, remove the control rod and measure the bearing wear with a dial indicator (Figure 2) using steps (a)(2)(i) through (a)(2)(vii).

(b) 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, Regulations Group, 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, Regulations Group.

Note 2:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Regulations Group.

(c) Special flight permits may be issued in accordance with 14 CFR 21.197 and 21.199 to operate the helicopter to a location where the requirements of this AD can be accomplished.

Issued in Fort Worth, Texas, on April 2, 2001.

Eric Bries,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.