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; Amendment 39-10429; AD 98-07-09]

RIN 2120-AA64

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.

[[Page 15755]]

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD),

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, that requires 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 amendment is prompted by two

reported incidents 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 this AD are intended to prevent failure of the damper link

assembly, which can result in degraded control response and subsequent

loss of control of the helicopter.

DATES: Effective May 6, 1998.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the federal Register as

of May 6, 1998.

ADDRESSES: The service information referenced in this AD 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

Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort

Worth, Texas; or at the Office of the Federal Register, 800 North

Capitol Street, NW., suite 700, Washington, DC.

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) 222-5783.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39) to include an airworthiness

directive (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 was published in the Federal Register on May 20, 1997 (62

FR 27554). That action proposed to 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.

Interested persons have been afforded an opportunity to participate

in the making of this amendment. Due consideration has been given to

the one comment received.

The commenter states that the helicopters are controllable with one

damper link disconnected. The commenter also states that a standard

AN970-3 safety washer drilled out to 0.250-inch and coned should be

allowed to be used as an alternate part to the BHTI safety washer kit.

The commenter states that the modified AN970-3 safety washer is the

same configuration as the BHTI safety washers used on the lateral

cyclic torque tube and only costs pennies.

The FAA does not concur with the comment. The commenter did not

provide any support for his statement that the helicopters are

controllable with one damper link disconnected. The commenter indicates

that he has been installing a modified safety washer on BHTI Model 47

series helicopters for decades. Although the commenter may believe that

his modified safety washer is as airworthy as BHTI's safety washer, he

has provided no engineering design data that support his assertion or

show that his modified safety washer is of the same configuration or of

the same material quality as BHTI's safety washer. Without such

supporting data, the FAA cannot approve the use of the commenter's

modified safety washer.

After careful review of the available data, including the comments

noted above, the FAA has determined that air safety and the public

interest require the adoption of the rule as proposed.

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

affected by this AD, that it will take approximately 1 work hour per

helicopter to accomplish the required actions, and that the average

labor rate is $60 per work hour. Required parts will cost approximately

$188 per helicopter. Based on these figures, the total cost impact of

the AD on U.S. operators is estimated to be $463,264.

The regulations adopted herein will 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 final

rule does not have sufficient federalism implications to warrant the

preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (1) is

not a ``significant regulatory action'' under Executive Order 12866;

(2) is not a ``significant rule'' under DOT Regulatory Policies and

Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action

and it is contained in the Rules Docket. A copy of it may be obtained

from the Rules Docket at the location provided under the caption

ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by

reference, Safety.

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the

Administrator, the Federal Aviation Administration amends 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:

AD 98-07-09 Bell Helicopter Textron, Inc.: Amendment 39-10429.

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

[[Page 15756]]

calendar days, 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 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

Secs. 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.

(d) The installation shall be done in accordance with Bell

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

August 16, 1996. This incorporation by reference was approved by the

Director of the Federal Register in accordance with 5 U.S.C. 552(a)

and 1 CFR part 51. Copies may be obtained from Bell Helicopter

Textron, Inc., P.O. Box 482, Fort Worth, Texas 76101. Copies may be

inspected at the FAA, Office of the Regional Counsel, Southwest

Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas; or at the

Office of the Federal Register, 800 North Capitol Street, NW., suite

700, Washington, DC.

(e) This amendment becomes effective on May 6, 1998.

Issued in Fort Worth, Texas, on March 24, 1998.

Eric Bries,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.

[FR Doc. 98-8466 Filed 3-31-98; 8:45 am]

BILLING CODE 4910-13-U