01-29593. Airworthiness Directives; Bell Helicopter Textron, Inc. Model 205A, 205A-1, 205B, 212, 412, 412EP, and 412CF Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) for Bell Helicopter Textron, Inc. (BHTI) Model 205A, 205A-1, 205B, 212, 412, 412EP, and 412CF helicopters. The AD would require inspecting each affected tail rotor blade forward tip weight retention block (tip block) and the aft tip closure (tip closure) for adhesive bond voids and removing any tail rotor blade with an excessive void from service. The AD would also require modifying certain tail rotor blades by installing shear pins and tip closure rivets. This proposal is prompted by five occurrences of missing tip blocks or tip closures resulting in minor to substantial damage. The actions specified by the proposed AD are intended to prevent loss of a tip block or tip closure, loss of a tail rotor blade, and subsequent loss of control of the helicopter.

DATES:

Comments must be received on or before January 28, 2002.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2001-SW-37-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:

Michael Kohner, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Rotorcraft Certification Office, Fort Worth, Texas 76193-0170, 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, 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 proposal must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket No. 2001-SW-37-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. 2001-SW-37-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

Discussion

This document proposes the adoption of a new AD for BHTI Model 205A, 205A-1, 205B, 212, 412, 412EP, and 412CF helicopters, with a tail rotor blade, part number (P/N) 212-010-750-009, -011, -105, -107, -109, or -111, having a serial number (S/N) prefix ATR or A3, or a S/N with a prefix A and a number less than or equal to 11529. The AD would require inspecting the tip block and the tip closure for adhesive bonding voids and removing any tail rotor blade with an excessive void from service. The AD would also require modifying certain tail rotor blades by installing shear pins and tip closure rivets in the tip area of affected tail rotor blades. This proposal is prompted by five occurrences of missing tip blocks and tip closures resulting in minor to substantial damage. This condition, if not corrected, could result in loss of the tip block or tip closure, loss of the tail rotor blade, and subsequent loss of control of the helicopter.

The FAA has reviewed BHTI Service Bulletins 205-00-80, 205B-00-34, 212-00-111, 412-00-106, and 412CF-00-13, all Revision A, all dated December 20, 2000. The service bulletins describe procedures for inspecting and modifying certain tail rotor blades and were issued as a result of an investigation of an in-flight loss of a tail rotor blade tip block, P/N 212-010-750-105. The investigation revealed that the countersunk screws retaining the tip block were installed incorrectly, resulting in inadequate tip block retention. Also, reports have been submitted about loss of the tail rotor tip closures possibly due to an inadequate adhesive bond in this area.

We have identified an unsafe condition that is likely to exist or develop on other BHTI Model 205A, 205A-1, 205B, 212, 412, 412EP, and 412CF helicopters of the same type design. Therefore, the proposed AD would require the following:

• Inspecting certain tail rotor blades' tip block and tip closure for voids.
• Removing any tail rotor blade that has a void in excess of specified limitations.
• Modifying certain tail rotor blades by installing shear pins.
• Modifying all affected S/N tail rotor blades by installing aft tip closure rivets.

The actions would be required to be accomplished in accordance with the service bulletins described previously.

The FAA estimates that 281 helicopters of U.S. registry would be affected by this proposed AD, that it would take approximately 3 work hours per helicopter to inspect certain tail rotor blades and to install the shear pins and tip closure rivets, and that the average labor rate is $60 per work hour. Required parts would cost approximately $25 per helicopter. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $57,605.

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 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:

Bell Helicopter Textron, Inc.: Docket No. 2001-SW-37-AD.

Applicability: Model 205A, 205A-1, 205B, 212, 412, 412EP, and 412CF helicopters with a tail rotor blade, part number 212-010-750-009, -011, -105, -107, -109, or -111, having a serial number (S/N) prefix ATR or A3, or a S/N with a prefix A and a number less than or equal to 11529, 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 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 (d) 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: Within 100 hours time-in-service, unless accomplished previously.

To prevent loss of the forward tip weight retention block (tip block) or aft tip closure (tip closure), loss of the tail rotor blade, and subsequent loss of control of the helicopter, accomplish the following:

(a) Inspect the tip block and tip closure for voids. Remove from service any tail rotor blade with a void in excess of that allowed by the Component Repair and Overhaul Manual limitations.

(b) Inspect the tip block attachment countersink screws in four locations to determine if the head of each countersunk screw is flush with the surface of the abrasion strip. The locations of these four screws are depicted on Figure 1 of Bell Helicopter Textron, Inc. Alert Service Bulletin 205-00-80, 205B-00-34, 212-00-111, 412-00-106, and 412CF-00-13, all Revision A, all dated December 20, 2000 (ASB). If any of these screws are set below the surface of the abrasion strip or are covered with filler material, install shear pins in accordance with the Accomplishment Instructions, Shear Pin Installation paragraphs, of the applicable ASB.

(c) Install the aft tip closure rivets on all affected tail rotor blades in accordance with the Accomplishment Instructions, Aft Tip Closure Rivet Installation paragraphs, of the applicable ASB.

(d) 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, 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 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.

(e) 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 November 20, 2001.

Eric Bries,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.