Airworthiness Directives; Bell Helicopter Textron, Inc. Model 206A, 206B, 206L, 206L-1, 206L-3, and 206L-4 Helicopters

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 94-SW-08-AD]

Airworthiness Directives; Bell Helicopter Textron, Inc. Model

206A, 206B, 206L, 206L-1, 206L-3, and 206L-4 Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: This document proposes the adoption of a new airworthiness

directive (AD) that is applicable to Bell Helicopter Textron, Inc.

Model 206A, 206B, 206L, 206L-1, 206L-3, and 206L-4 helicopters. This

proposal would require removal and replacement of certain crosstube

assemblies (crosstubes). This proposal is prompted by two accidents

attributed to crosstube failures, as well as 27 field reports that

indicate that corrosion or metal fatigue may cause a failure of the

affected crosstubes. The actions specified by the proposed AD are

intended to prevent failure of the crosstubes and subsequent loss of

control of the helicopter.

DATES: Comments must be received by January 13, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Office of the Assistant Chief Counsel, Attention:

Rules Docket No. 94-SW-08-AD, 2601 Meacham Blvd., Room 663, Fort Worth,

Texas 76137. Comments may be inspected at this location between 9:00

a.m. and 3:00 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Ms. Sharon Miles, Aerospace Engineer,

Rotorcraft Certification Office, FAA, Rotorcraft Directorate, Fort

Worth, Texas, 76193-0170, telephone (817) 222-5172, fax (817) 222-5959.

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 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. 94-SW-08-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 Assistant Chief Counsel, Attention: Rules

Docket No. 94-SW-08-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas

76137.

Discussion

This notice proposes the adoption of a new airworthiness directive

(AD), that is applicable to Bell Helicopter Textron, Inc. (BHTI) Model

206A, 206B, 206L, 206L-1, 206L-3, and 206L-4 helicopters, equipped with

crosstube assemblies (crosstubes), BHTI part numbers (P/N) 206-050-107,

206-050-119, 206-050-134, 206-050-157, 206-050-169, 206-053-109, 206-

053-119, and 206-053-129 (all dash numbers), or Airborne Supply, Inc.

P/N AB206-050-107, AB206-050-119, or AB206-053-109. There have been at

least two accidents attributed to failures of the crosstubes.

Additionally, 27 field reports indicated that corrosion or metal

fatigue may contribute to cracking of the crosstubes. This condition,

if not corrected, could result in failure of the crosstubes and

subsequent loss of control of the helicopter.

Since an unsafe condition has been identified that is likely to

exist or develop on other Bell Helicopter Textron, Inc. Model 206A,

206B, 206L, 206L-1, 206L-3, and 206L-4 helicopters of the same type

design, the proposed AD would require removal and replacement of

certain crosstubes within the next 90 calendar days.

The FAA estimates that 5,700 helicopters of U.S. registry would be

affected by this proposed AD, that it would take approximately 10 work

hours per helicopter to accomplish the proposed actions, and that the

average labor rate is $60 per work hour. Required parts would cost

approximately $6,400 per helicopter. Based on these figures, the total

cost impact of the proposed AD on U.S. operators is estimated to be

$39,900,000 to replace two crosstubes per helicopter.

The regulations proposed herein would 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

proposal would not have sufficient federalism implications to warrant

the preparation of a Federalism Assessment.

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. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding a new airworthiness directive

to read as follows:

Bell Helicopter Textron, Inc. (BHTI): Docket No. 94-SW-08-AD.

Applicability: Model 206A, 206B, 206L, 206L-1, 206L-3, and 206L-

4 helicopters, crosstube assemblies (crosstubes), BHTI part numbers

(P/N) 206-050-107, 206-050-119, 206-050-134, 206-050-157, 206-050-

169, 206-053-109, 206-053-119, and 206-053-129 (all dash numbers),

or Airborne Supply, Inc. P/N AB206-050-107, AB206-050-119, or AB206-

053-109 (all dash numbers) installed, certified in any category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent failure of the crosstubes and subsequent loss of

control of the helicopter, accomplish the following:

(a) Within 90 calendar days after the effective date of this AD,

remove any affected crosstube listed in the ``Applicability''

paragraph of this AD, and replace with an airworthy crosstube in

accordance with the appropriate maintenance manual or service

instructions. Any crosstubes removed as a result of this AD shall be

permanently marked as unairworthy.

Note 1: For BHTI P/N 206-053-109 and 206-053-119, the P/N are

vibro-etched on the upper cuff of the crosstube on the aft side on

both forward and aft crosstubes; for BHTI P/N 206-053-129, the P/N

are vibro-etched on the bottom of the cuff on the aft side on both

forward and aft crosstubes; for BHTI P/N 206-050-107, 206-050-119,

206-050-134, 206-050-157, and 206-050-169, the P/N are stamped in

ink on the crosstube, which is shipped without paint (once the

helicopter is painted, the P/N are covered); and for Airborne

Supply, Inc., P/N AB206-050-107, AB206-050-119, and AB206-053-109,

the P/N are rubber stamped at the bottom end of the crosstube.

(b) If the crosstubes' P/N cannot be determined by reference to

the crosstubes, if possible, determine the P/N by reference to the

maintenance records or other aircraft records. If the crosstubes' P/

N cannot be determined, replace the crosstubes with airworthy

crosstubes within 90 calendar days after the effective date of this

AD in accordance with the appropriate maintenance manual or service

instructions.

(c) 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 Certification Office,

FAA, Rotorcraft Directorate. 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.

(d) 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.

Issued in Fort Worth, Texas, on November 3, 1994.

Eric Bries,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.

[FR Doc. 94-27928 Filed 11-10-94; 8:45 am]

BILLING CODE 4910-13-P