Airworthiness Directives; Bell Helicopter Textron, Inc. Model 214B, 214B-1, and 214ST Helicopters

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-SW-12-AD; Amendment 39-10886; AD 98-23-18]

RIN 2120-AA64

Airworthiness Directives; Bell Helicopter Textron, Inc. Model

214B, 214B-1, and 214ST Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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

is applicable to Bell Helicopter Textron, Inc. (Bell) Model 214B, 214B-

1, and 214ST helicopters. This action requires a visual inspection of

thin-flanged attachment barrel nuts (barrel nuts) manufactured by

Kaynar Technologies, Inc. for cracks or lubrication residue, and

replacement of the barrel nuts and corresponding attaching bolts, as

necessary. These barrel nuts have been installed in main rotor grips,

pitch horns, and tailboom assemblies. This amendment is prompted by a

report of a cracked barrel nut, which was discovered on a helicopter

being prepared for shipment. The actions specified in this AD are

intended to detect cracks in a barrel nut, which could lead to failure

of a main rotor grip, pitch horn, or tailboom, and subsequent loss of

control of the helicopter.

DATES: Effective November 30, 1998.

The incorporation by reference of certain publications listed in

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

of November 30, 1998.

Comments for inclusion in the Rules Docket must be received on or

before January 12, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Office of the Regional Counsel, Southwest Region,

Attention: Rules Docket No. 98-SW-12-AD, 2601 Meacham Blvd., Room 663,

Fort Worth, Texas 76137.

The service information referenced in this AD may be obtained from

Bell Helicopter Textron, Inc., P.O. Box 482, Fort Worth, Texas 76101,

telephone (817) 280-3391, fax (817) 280-6466. This information may be

examined at the FAA, Office of the Regional Counsel, Southwest Region,

2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137; or at the Office

of the Federal Register, 800 North Capitol Street, NW., suite 700,

Washington, DC.

FOR FURTHER INFORMATION CONTACT: Ms. Karen Forest, Aerospace Engineer,

FAA, Rotorcraft Directorate, Rotorcraft Certification Office, 2601

Meacham Blvd., Fort Worth, Texas, 76137, telephone (817) 222-5861, fax

(817) 222-5783.

SUPPLEMENTARY INFORMATION: This amendment adopts a new airworthiness

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

(Bell) Model 214B, 214B-1, and 214ST helicopters. This action requires

an inspection of barrel nuts manufactured by Kaynar Technologies, Inc.

(Kaynar). This amendment is prompted by the discovery of a cracked

barrel nut, part number NAS577B-10A, on a helicopter being disassembled

for shipment. The crack was in the threaded portion of the barrel nut.

A laboratory analysis indicated that the cracking is a result of

hydrogen embrittlement introduced during manufacture. These nuts may

have been installed in spare main rotor grips, pitch horns, or tailboom

assemblies; and may also have been supplied as individual spare parts.

The actions specified in this AD are intended to detect cracks in a

barrel nut, which could lead to failure of a main rotor grip, pitch

horn, or tailboom, and subsequent loss of control of the helicopter.

The FAA has reviewed Bell Helicopter Textron, Inc. Alert Service

Bulletin No. 214-97-59 and Bell Helicopter Textron, Inc. Alert Service

Bulletin No. 214ST-97-78, both dated July 17, 1997, which describe

procedures for determining if any barrel nuts used on the affected

model helicopters were manufactured by Kaynar, and if so, visually

inspecting those barrel nuts for cracks or lubrication residue using a

10-power or higher magnifying glass. If a crack or lubrication residue

is discovered in the threads of either a barrel nut or its attaching

bolt, both the barrel nut and the attaching bolt must be replaced with

airworthy parts. Barrel nuts whose manufacturer cannot be positively

identified must also be replaced.

Since an unsafe condition has been identified that is likely to

exist or develop on other Bell Model 214B, 214B-1, and 214ST

helicopters of the same type design, this AD is being issued to detect

cracking in a barrel nut, which could lead to failure of a main rotor

grip, pitch horn, or tailboom, and subsequent loss of control of the

helicopter. The actions are required to be accomplished in accordance

with the service bulletins described previously.

[[Page 63401]]

The short compliance time involved is required because the previously

described critical unsafe condition can adversely affect the structural

integrity of the helicopter. Therefore, an inspection of the barrel

nuts is required within 40 hours time-in-service, and this AD must be

issued immediately.

Since a situation exists that requires the immediate adoption of

this regulation, it is found that notice and opportunity for prior

public comment hereon are impracticable, and that good cause exists for

making this amendment effective in less than 30 days.

The FAA estimates that 15 helicopters of U.S. registry will be

affected by this proposed AD, that it will take approximately 3.0 work

hours per helicopter to accomplish the inspection and replacement of

parts, and that the average labor rate is $60 per work hour. Required

parts will cost approximately $600 per helicopter. Based on these

figures, the total cost impact of the proposed AD on U.S. operators is

estimated to be $11,700.

Comments Invited

Although this action is in the form of a final rule that involves

requirements affecting flight safety and, thus, was not preceded by

notice and an opportunity for public comment, comments are invited on

this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All

communications received on or before the closing date for comments will

be considered, and this rule may be amended in light of the comments

received. Factual information that supports the commenter's ideas and

suggestions is extremely helpful in evaluating the effectiveness of the

AD action and determining whether additional rulemaking action would be

needed.

Comments are specifically invited on the overall regulatory,

economic, environmental, and energy aspects of the rule that might

suggest a need to modify the 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 that

summarizes each FAA-public contact concerned with the substance of this

AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments

submitted in response to this rule must submit a self-addressed,

stamped postcard on which the following statement is made: ``Comments

to Docket No. 98-SW-12-AD.'' The postcard will be date stamped and

returned to the commenter.

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.

The FAA has determined that this regulation is an emergency

regulation that must be issued immediately to correct an unsafe

condition in aircraft, and that it is not a ``significant regulatory

action'' under Executive Order 12866. It has been determined further

that this action involves an emergency regulation under DOT Regulatory

Policies and Procedures (44 FR 11034, February 26, 1979). If it is

determined that this emergency regulation otherwise would be

significant under DOT Regulatory Policies and Procedures, a final

regulatory evaluation will be prepared and placed in the Rules Docket.

A copy of it, if filed, 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 98-23-18 Bell Helicopter Textron, Inc.: Amendment 39-10886.

Docket No. 98-SW-12-AD.

Applicability: Model 214B, 214B-1, and 214ST 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 (e) 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 40 hours time-in-service, unless

accomplished previously.

To detect cracks in a barrel nut, which could lead to failure of

a main rotor grip, pitch horn, or tailboom, and subsequent loss of

control of the helicopter, accomplish the following:

(a) For each barrel nut, determine if the manufacturer was

Kaynar Technologies Inc. (Kaynar) in accordance with paragraph 1.a.

of the Accomplishment Instructions of Bell Helicopter Textron, Inc.

Alert Service Bulletin (ASB) No. 214-97-59, applicable to Model 214B

and B-1 helicopters, or Bell Helicopter Textron, Inc. ASB No. 214ST-

97-78, applicable to Model 214ST helicopters, both dated July 17,

1997.

(b) For each Kaynar-manufactured barrel nut, part number (P/N)

NAS577B-10A, determine if it is a ``thick'' flange barrel nut

(installed edge distance of 0.115-inch) or a ``thin flange barrel

nut (installed edge distance of 0.155-inch) in accordance with

paragraph 1.b of the Accomplishment Instructions of the applicable

ASB, dated July 17, 1997.

(c) For each barrel nut identified as a Kaynar-manufactured

``thin'' flange barrel nut, using a 10-power or higher magnifying

glass, perform a visual inspection for cracks in the threaded

portion of each barrel nut or lubrication residue in the threaded

portion of each barrel nut or its corresponding attaching bolt.

Note 2: If a ``thick'' flange Kaynar-manufactured barrel nut, P/

N NAS577B-10A, is installed, compliance with paragraphs (d) and (e)

of this AD is not required.

(d) For each barrel nut that cannot be positively identified,

and for each Kaynar-manufactured ``thin'' flange barrel nut in which

a crack or lubrication residue was discovered as a result of the

inspection required by paragraph (c) of this AD, replace the barrel

nut and the corresponding attaching bolt with an airworthy barrel

nut and attaching bolt before further flight. If an unairworthy

barrel nut is found at the right-hand upper tailboom attachment

location, also replace the left-hand upper barrel nut and

corresponding bolt, and inspect both upper tailboom and fuselage

longeron fittings for damage or deformation.

(e) An alternative method of compliance or adjustment of the

compliance time that provides an acceptable level of safety may be

[[Page 63402]]

used if approved by the Manager, FAA, Rotorcraft Directorate,

Rotorcraft Certification Office. 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 3: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Rotorcraft Certification Office.

(f) 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.

(g) The identification and determination of the barrel

dimensions shall be done in accordance with Bell Helicopter Textron,

Inc. ASB No. 214-97-59 or Bell Helicopter Textron, Inc. ASB No.

214ST-97-78, both dated July 17, 1997. 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, telephone (817) 280-3391, fax (817) 280-6466.

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.

(h) This amendment becomes effective on November 30, 1998.

Issued in Fort Worth, Texas on November 4, 1998.

Mark R. Schilling,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.

[FR Doc. 98-30165 Filed 11-12-98; 8:45 am]

BILLING CODE 4910-13-U