Airworthiness Directives; Bell Helicopter Textron, Inc. Model 212 Helicopters

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-SW-20-AD; Amendment 39-11010; AD 98-11-15]

RIN 2120-AA64

Airworthiness Directives; Bell Helicopter Textron, Inc. Model 212

Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This document publishes in the Federal Register an amendment

adopting Airworthiness Directive (AD) 98-11-15, which was sent

previously to all known U.S. owners and operators of Bell Helicopter

Textron, Inc. (BHTI) Model 212 helicopters by individual letters. This

AD requires inspecting the trunnion assembly or tail rotor flapping

stop (flapping stop), whichever is applicable, installing a trunnion

assembly or flapping stop, if necessary; and replacing the tail rotor

yoke (yoke). This amendment is prompted by an accident involving a BHTI

Model 205A-1 helicopter in which the yoke failed during flight. This

condition, if not corrected, could lead to failure of the yoke, loss of

the tail rotor, and subsequent loss of control of the helicopter.

DATES: Effective February 10, 1999, to all persons except those persons

to whom it was made immediately effective by priority letter AD 98-11-

15, issued on May 19, 1998, which contained the requirements of this

amendment.

The incorporation by reference of certain publications listed in

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

of February 10, 1999.

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

before March 29, 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-20-AD, 2601 Meacham Blvd., Room 663,

Fort Worth, Texas 76137.

The applicable service information 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; or at the Office of

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

Washington, DC.

FOR FURTHER INFORMATION CONTACT: Sandra Shelly, Aerospace Engineer,

FAA, Rotorcraft Certification Office, Rotorcraft Directorate, 2601

Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5177, fax

(817) 222-5783.

SUPPLEMENTARY INFORMATION: On May 19, 1998, the FAA issued priority

letter AD 98-11-15, applicable to BHTI Model 212 helicopters, which

requires, before further flight, reviewing historical records of the

helicopter and the yoke assembly to detect any usage or event that may

have imposed an excessive bending load on the yoke. If such usage or

event occurred, before further flight, this AD requires replacing the

yoke assembly with an airworthy yoke assembly that has zero-hours TIS,

or that has passed an x-ray diffraction inspection in accordance with

Bell Helicopter Textron, Inc. Alert Service Bulletin (ASB) 212-96-100,

Revision A, dated May 18, 1998, or ASB 212-96-101, dated September 3,

1996, whichever is applicable, as well as installing an airworthy

trunnion assembly or an airworthy flapping stop, depending on which

part-numbered yoke assembly is installed. If no usage or event that may

have imposed an excessive bending load on the yoke has occurred, the

yoke must be replaced within 180 calendar days. Thereafter, at

intervals not to exceed 25 hours TIS, or before further flight after

any incident that may have imposed an excessive bending load on the

yoke, this AD requires inspecting the trunnion assembly or the tail

rotor flapping stop, whichever is applicable, for yielding. If yielding

is detected, the yoke assembly and trunnion assembly or flapping stop,

whichever is applicable, must be replaced. That action was prompted by

an accident involving a BHTI Model 205A-1 helicopter in which the yoke

failed during flight. The Model 205A-1 helicopter is similar in design

to the Model 212 helicopter. Investigation of the accident revealed

that the yoke assembly service life may be reduced due to unforeseen

static and dynamic

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loading of the tail rotor. This condition, if not corrected, could lead

to failure of the yoke, loss of the tail rotor, and subsequent loss of

control of the helicopter.

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

Bulletin (ASB) No. 212-96-100, Revision A, dated May 18, 1998, which

specifies inspections of the yoke assembly and trunnion assembly, and

replacement of certain trunnion assemblies; and ASB 212-96-101, dated

September 3, 1996, which specifies inspections of the yoke assembly,

and installation of a tail rotor flapping stop.

Since an unsafe condition has been identified that is likely to

exist or develop on other BHTI Model 212 helicopters of the same type

design, this AD requires, before further flight, reviewing historical

records of the helicopter and the yoke assembly to detect any usage or

event that may have imposed an excessive bending load on the yoke. If

such usage or event occurred, before further flight, this AD requires

replacing the yoke assembly with an airworthy yoke assembly that has

zero-hours TIS, or that has passed an x-ray diffraction inspection in

accordance with ASB 212-96-100, Revision A, dated May 18, 1998, or ASB

212-96-101, dated September 3, 1996, whichever is applicable, as well

as installing an airworthy trunnion assembly or an airworthy flapping

stop, depending on which part-numbered yoke assembly is installed. If

no such usage or event has occurred, the yoke must be replaced within

180 calendar days. Thereafter, at intervals not to exceed 25 hours TIS,

or before further flight after any incident that may have imposed an

excessive bending load on the yoke, this AD requires inspecting the

trunnion assembly or the tail rotor flapping stop, whichever is

applicable, for yielding. If yielding is detected, the yoke assembly

and trunnion assembly or flapping stop, whichever is applicable, must

be replaced. The actions are required to be accomplished in accordance

with the service bulletins described previously. The short compliance

time involved is required because the previously described critical

unsafe condition can adversely affect the controllability and

structural integrity of the helicopter, and the yoke assembly may need

to be replaced immediately.

Since it was found that immediate corrective action was required,

notice and opportunity for prior public comment thereon were

impracticable and contrary to the public interest, and good cause

existed to make the AD effective immediately by individual letters

issued on May 19, 1998 to all known U.S. owners and operators of BHTI

Model 212 helicopters. These conditions still exist, and the AD is

hereby published in the Federal Register as an amendment to Sec. 39.13

of the Federal Aviation Regulations (14 CFR 39.13) to make it effective

to all persons.

The FAA estimates that 250 helicopters of U.S. registry will be

affected by this AD, that it will take approximately 9 work hours per

helicopter to accomplish the inspections and installations, and that

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

approximately $6,637 for each yoke, $1,028 for each trunnion assembly,

and $936 for each flapping stop per helicopter. Based on these figures,

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

$2,051,250 if both the yoke and the trunnion assembly are replaced in

the entire fleet.

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-20-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 98-11-15 Bell Helicopter Textron Inc.: Amendment 39-11010. Docket

No. 98-SW-20-AD.

Applicability: Model 212 helicopters, with tail rotor yoke

assembly, part number (P/N) 212-010-704-all dash numbers, P/N 212-010-

744-all dash numbers, or P/N 212-011-702-all dash

[[Page 3821]]

numbers, 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

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 (d) 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 as indicated, unless accomplished

previously.

To prevent failure of the tail rotor yoke (yoke), loss of the

tail rotor, and subsequent loss of control of the helicopter,

accomplish the following:

(a) Before further flight, review all historical records of the

helicopter and the tail rotor yoke assembly (yoke assembly) for any

static or dynamic incident history that could have imposed an

excessive bending load on the yoke. If such a history exists, comply

with paragraph (b) of this AD before further flight.

Note 2: Examples of excessive bending loads include exposure to

high wind gusts (such as those from rotor wash or prop blast),

improper ground handling (in which the tail rotor blade has been

used as a hand hold), improper feathering bearing removal (in which

the yoke is not properly supported when pressing out bearings), a

static ground strike of some type (such as being struck by a

vehicle), or an incident in which a damaged tail rotor blade was

replaced due to a blade strike.

(b) Within the next 180 calendar days, remove the yoke assembly

and replace it with an airworthy yoke assembly having zero hours

time-in-service (TIS), or with an airworthy yoke assembly

(regardless of TIS) that has passed an x-ray diffraction inspection

in accordance with Bell Helicopter Textron, Inc. Alert Service

Bulletin (ASB) 212-96-100, Revision A, dated May 18, 1998, or ASB

212-96-101, dated September 3, 1996, whichever is applicable. When

the yoke assembly is replaced, for helicopters with a yoke assembly,

P/N 212-011-702-all dash numbers, install an airworthy tail rotor

flapping stop, P/N 212-011-713-103 and for helicopters with yoke

assemblies, P/N 212-010-704-all dash numbers or P/N 212-010-744-all

dash numbers, install an airworthy trunnion assembly, P/N 212-010-

738-001. If any incident as described in paragraph (a) of this AD

occurs after the effective date of this AD and prior to compliance

with this paragraph, then compliance with this paragraph is required

before further flight.

Note 3: Yoke assemblies that have passed an x-ray diffraction

inspection at BHTI will have the letters ``FM'' vibro-etched on them

following the serial number.

(c) After accomplishing the requirements of paragraph (b) of

this AD, thereafter, at intervals not to exceed 25 hours TIS, or

before further flight after any incident as described in paragraph

(a) of this AD, inspect the trunnion assembly and replace the yoke

assembly and trunnion assembly, if required, in accordance with Part

III, Paragraph 1, of ASB 212-96-100, Revision A, dated May 18, 1998;

or inspect the tail rotor flapping stop and replace the yoke

assembly and flapping stop, if required, in accordance with Part

III, Paragraphs 1, 2, and 3, of ASB 212-96-101, dated September 3,

1996, whichever is applicable.

(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. 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, Rotorcraft Directorate.

Note 4: 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

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.

(f) The inspection shall be done in accordance with ASB 212-96-

100, Revision A, dated May 18, 1998, or ASB 212-96-101, dated

September 3, 1996, whichever is applicable. 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 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.

(g) This amendment becomes effective on February 10, 1999, to

all persons except those persons to whom it was made immediately

effective by Priority Letter AD 98-11-15, issued May 19, 1998, which

contained the requirements of this amendment.

Issued in Fort Worth, Texas, on January 13, 1999.

Eric Bries,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.

[FR Doc. 99-1351 Filed 1-25-99; 8:45 am]

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