00-18405. Airworthiness Directives; Eurocopter France Model AS-350B, BA, B1, B2, B3, C, D, and D1, and AS-355E, F, F1, F2 and N Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the supersedure of an existing airworthiness directive (AD) that applies to Eurocopter France Model AS-350B, BA, B1, B2, C, D, and D1, and AS-355E, F, F1, and F2 helicopters. That AD currently requires inspections of the main rotor head components, the main gearbox (MGB) suspension bars, and the ground resonance prevention system components. This action would require those same inspections, but would also apply to Model AS-350B3 and AS-355N helicopters. This proposal is prompted by the inadvertent omission of those model helicopters from the previous AD. The actions specified by the proposed AD are intended to prevent ground resonance due to reduced structural stiffness, which could lead to failure of a main rotor head or MGB suspension component and subsequent loss of control of the helicopter.

DATES:

Comments must be received on or before September 18, 2000.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2000-SW-25-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. You may also send comments electronically to the Rules Docket at the following address: [e-mail]. Comments may be inspected at the Office of the Regional Counsel between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT:

Jim Grigg, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Rotorcraft Standards Staff, 2601 Meacham Blvd., Fort Worth, Texas 76137, 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, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice 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, both before and after the closing date for comments, 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 notice must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket No. 2000-SW-25-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

You 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-25-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

Discussion

On April 4, 2000, the FAA revised AD 86-15-10, Amendment 39-5517 (52 FR 13233, April 22, 1987) by issuing AD 86-15-10 R2, Amendment 39-11681 (65 FR 20721, April 18, 2000). That revision requires an initial inspection at 10 hours time-in-service (TIS) and then repetitive inspections at intervals not to exceed 500 hours TIS of the main rotor head components, the MGB suspension bars, and the ground resonance prevention system components. The revision was prompted by reports of confusion and unnecessary costs associated with the difference in the previously-required 400 hours TIS inspection interval and the current manufacturer's master service recommendation of 500 hours TIS inspection interval. The requirements of that revised AD are intended to eliminate confusion and unnecessary costs and to prevent ground resonance due to reduced structural stiffness, which could lead to failure of a main rotor head or MGB suspension component and subsequent loss of control of the helicopter.

Since the issuance of that AD, the FAA has determined that Model AS-350B3 and AS-355N helicopters were inadvertently omitted from the applicability of the revised AD. Model AS-350B3 was omitted because it is a newer model helicopter and was not part of the Type Certificate Data Sheet when the revised AD was issued. Model AS-355N was included in the preamble of AD 86-15-10 R2, but was inadvertently omitted in the applicability list of that AD.

Since an unsafe condition has been identified that is likely to exist or develop on other Model AS-350B, BA, B1, B2, B3, C, D, and D1, and AS-355E, F, F1, F2 and N helicopters of the same type design, the proposed AD would supersede AD 86-15-10, AD 86-15-10 R1, and AD 86-15-10 R2 to require repetitive inspections of the main rotor head components, the MGB suspension bars, and the ground resonance prevention system components at intervals not to exceed 500 hours TIS.

The FAA estimates that 586 helicopters of U.S. registry would be affected by this proposed AD, that it would take approximately 8 work hours per helicopter to accomplish the proposed actions, and that the average labor rate is $60 per work hour. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $480 per helicopter, or $281,280 for the entire fleet.

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 39-11681 (65 FR 20721, April 18, 2000), Amendment 39-6515 (55 FR 5833, February 20, 1990) and Amendment 39-5517 (52 FR 13233, April 22, 1987), and by adding a new airworthiness directive (AD), to read as follows:

Eurocopter France: Docket No. 2000-SW-25-AD. Supersedes AD 86-15-10 R2, Amendment 39-11681, Docket No. 98-SW-82-AD; AD 86-15-10R1, Amendment 39-6515, Docket No. 86-ASW-22; and AD 86-15-10, Amendment 39-5517, Docket No. 86-ASW-22.

Applicability: Model AS-350B, BA, B1, B2, B3, C, D, and D1, and AS-355E, F, F1, F2 and N helicopters, certificated in any category.

Note 1:

This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been otherwise 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 (f) of this AD. The 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 ground resonance due to reduced structural stiffness, which could lead to failure of a main rotor head or main gearbox (MGB) suspension component and subsequent loss of control of the helicopter, accomplish the following:

(a) Within 10 hours time-in-service (TIS):

(1) For Model AS-350B, BA, B1, B2, B3, C, D, and D1 helicopters, inspect the main rotor head components, the MGB suspension bars (struts), and the landing gear ground resonance prevention components (aft spring blades and hydraulic shock absorbers) in accordance with paragraph CC.3 of Aerospatiale Service Bulletin (SB) No. 01.17a (not dated).

(2) For Model AS-355E, F, F1, F2, and N helicopters, inspect the main rotor head components, the MGB suspension bars (struts), and the landing gear ground resonance prevention components (aft spring blades and hydraulic shock absorbers) in accordance with paragraph CC.3 of SB No. 01.14a (not dated).

(b) Rework or replace damaged components in accordance with SB No. 01.17a or SB No. 01.14a, as applicable.

(c) Repeat the inspections and rework required by paragraphs (a) and (b) of this AD at intervals not to exceed 500 hours TIS.

(d) If the helicopter is subjected to a hard landing or to high surface winds when parked without effective tiedown straps installed, repeat the inspections required by paragraph (a) of this AD for the main rotor head star arms and the MGB suspension bars (struts) before further flight.

(e) After a landing with abnormal self-sustained dynamic vibrations (ground resonance type vibrations), repeat all the inspections required by paragraph (a) of this AD.

(f) 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.

(g) Special flight permits may be issued in accordance with §§ 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.

Issued in Fort Worth, Texas, on July 12, 2000.

Henry A. Armstrong,

Manager, Rotorcraft Directorate, Aircraft Certification Service.