Airworthiness Directives; Bell Helicopter Textron, Inc. Model 47B, 47B-3, 47D, 47D-1, 47G, 47G-2, 47G-2A, 47G-2A-1, 47G-3, 47G-3B, 47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-4, 47G-4A, 47G-5, 47G-5A, 47H-1, 47J, 47J-2, 47J-2A, and 47K Helicopters

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-SW-28-AD]

Airworthiness Directives; Bell Helicopter Textron, Inc. Model

47B, 47B-3, 47D, 47D-1, 47G, 47G-2, 47G-2A, 47G-2A-1, 47G-3, 47G-3B,

47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-4, 47G-4A, 47G-5, 47G-5A, 47H-1,

47J, 47J-2, 47J-2A, and 47K Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY:This document proposes the adoption of a new airworthiness

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

(BHTI) Model 47B, 47B-3, 47D, 47D-1, 47G, 47G-2, 47G-2A, 47G-2A-1, 47G-

3, 47G-3B, 47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-4, 47G-4A, 47G-5, 47G-5A,

47H-1, 47J, 47J-2, 47J-2A, and 47K helicopters. This proposal would

require installing a safety washer kit designed to preclude separation

of the stabilizer bar damper link (damper link) if the damper link rod

end bushing (bushing) loosens and exits the damper link rod end. This

proposal is prompted by two reported incidences in which the bushings

loosened and exited the damper link rod ends, allowing the damper link

to slide over the retention bolt and separate from the stabilizer bar

(in the first incident), and from the hydraulic damper (in the second

incident). The actions specified by the proposed AD are intended to

prevent failure of the stabilizer bar damper link assembly, which can

result in degraded control response and subsequent loss of control of

the helicopter.

DATES: Comments must be received by July 21,1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

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

Rules Docket No. 96-SW-28-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.

The service information referenced in the proposed rule may be

obtained from Bell Helicopter Textron, Inc., P.O. Box 482, Fort Worth,

Texas 76101. This information may be examined at the FAA, Office of the

Assistant Chief Counsel, 2601 Meacham Blvd., Room 663, Fort Worth,

Texas.

FOR FURTHER INFORMATION CONTACT: Mr. Jurgen E. Priester, Aerospace

Engineer, Rotorcraft Certification Office, Rotorcraft Directorate, FAA

2601 Meacham Blvd., Fort Worth, Texas 76137; telephone (817) 222-5159,

fax (817) 222-5960.

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

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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. 96-SW-28-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. 96-SW-28-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas

76137.

Discussion

This document proposes the adoption of a new AD that is applicable

to BHTI Model 47B, 47B-3, 47D, 47D-1, 47G, 47G-2, 47G-2A, 47G-2A-1,

47G-3, 47G-3B, 47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-4, 47G-4A, 47G-5,

47G-5A, 47H-1, 47J, 47J-2, 47J-2A, and 47K helicopters. This proposal

would require installing a safety washer kit designed to preclude

separation of the damper link if the bushing loosens and exits the

damper link rod end. This proposal is prompted by two reported

incidences in which the bushings loosened and exited the damper link

rod ends, allowing the damper link to slide over the retention bolt and

separate from the stabilizer bar (in the first incident), and from the

hydraulic damper (in the second incident). In the first incident, an

inspection revealed that the rod end bearing had not been lubricated

for an extended period of time prior to failure. In the second

incident, a pilot safely landed the aircraft after reporting degraded

control response. A post-flight inspection revealed that one damper

link had separated from the hydraulic damper. A later inspection

indicated that the bushing had not been properly roll-staked by the

damper manufacturer. Therefore, one of the occurrences is attributed to

a quality control problem with the damper link manufacturer. This

condition, if not corrected, could result in failure of the stabilizer

bar damper link assembly, which can result in degraded control response

and subsequent loss of control of the helicopter.

The FAA has reviewed BHTI Alert Service Bulletin (ASB) No. 47-96-

22, dated August 16, 1996, which describes procedures for removing and

marking the stabilizer and damper link assemblies, installing a safety

washer kit, part number (P/N) CA-047-96-022-1, applying a corrosion

preventive compound, and reinstalling the stabilizer bar damper link

assemblies. The ASB states that these actions are to be accomplished at

the next 100-hour inspection, or no later than December 31, 1996. The

FAA has determined that the compliance time should be within the next

100 hours time-in-service (TIS) or no later than 120 calendar days

after the effective date of the AD, whichever occurs first.

Since an unsafe condition has been identified that is likely to

exist or develop on other BHTI Model 47B, 47B-3, 47D, 47D-1, 47G, 47G-

2, 47G-2A, 47G-2A-1, 47G-3, 47G-3B, 47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-

4, 47G-4A, 47G-5, 47G-5A, 47H-1, 47J, 47J-2, 47J-2A, and 47K

helicopters of the same type design, the proposed AD would require,

within the next 100 hours TIS or within the next 120 calendar days

after the effective date of the proposed AD, whichever occurs first,

removing and marking the stabilizer and damper link assemblies,

installing a safety washer kit, P/N CA-047-96-022-1, applying a

corrosion preventive compound, and reinstalling the stabilizer and

damper link assemblies. The actions would be required to be

accomplished in accordance with the service bulletin described

previously.

The FAA estimates that 1,868 helicopters of U.S. registry would be

affected by this proposed AD, that it would take 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 $188 per helicopter. Based on these figures, the total

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

$463,264.

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. 106(g), 40113, 44701.

Sec. 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. 96-SW-28-AD.

Applicability: Model 47B, 47B-3, 47D, 47D-1, 47G, 47G-2, 47G-2A,

47G-2A-1, 47G-3, 47G-3B, 47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-4, 47G-

4A, 47G-5, 47G-5A, 47H-1, 47J, 47J-2, 47J-2A, and 47K 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

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 include an 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 the next 100 hours time-in-service

or within the next 120 calendar days after the effective date of

this AD, whichever occurs first, unless accomplished previously.

To prevent failure of the stabilizer bar damper link assembly,

which can result in degraded control response and subsequent loss of

control of the helicopter, accomplish the following:

(a) Remove the stabilizer bar damper link assemblies from the

helicopter, install a

[[Page 27556]]

safety washer kit, part number (P/N) CA-047-96-022-1, and reinstall

the stabilizer bar damper link assemblies onto the helicopter in

accordance with the Accomplishment Instructions contained in Bell

Helicopter Textron, Inc. Alert Service Bulletin No. 47-96-22, dated

August 16, 1996.

(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, 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.

(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.

Issued in Fort Worth, Texas, on May 9, 1997.

Eric Bries,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.

[FR Doc. 97-13083 Filed 5-19-97; 8:45 am]

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