Airworthiness Directives; Bell Helicopter Textron, Inc. Model 214ST Helicopters

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-SW-27-AD; Amendment 39-11037; AD 99-04-13]

RIN 2120-AA64

Airworthiness Directives; Bell Helicopter Textron, Inc. Model

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. (BHTI) Model 214ST

helicopters. This action requires a reduction of the never-exceed

velocity (Vne) limitation until an inspection of the tail rotor yoke

(yoke) assembly for fatigue damage and installation of a redesigned

yoke flapping stop are accomplished. Recurring periodic and special

inspections to detect occurrences of yoke overload are also required.

This amendment is prompted by reports of inflight failures of yokes

installed on civilian and military helicopters of similar type design.

The actions specified in this AD are intended to prevent fatigue

failure of the yoke that could result in loss of the tail rotor and

subsequent loss of control of the helicopter.

DATES: Effective March 4, 1999.

The incorporation by reference of certain publications listed in

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

of March 4, 1999.

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

before April 19, 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-27-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: Mr. Harry Edmiston, Aerospace

Engineer, Rotorcraft Certification Office, Rotorcraft Directorate, FAA,

2601 Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5158,

fax (817) 222-5783.

SUPPLEMENTARY INFORMATION: This amendment adopts a new AD that is

applicable to BHTI Model 214ST helicopters. This action requires,

before further flight, reviewing the historical records for any

incidents that may have imposed greater than normal bending loads on

the tail rotor yoke, installing a placard on the instrument panel with

a reduced airspeed limitation, and inserting the limitation into the

Limitations section of the Rotorcraft Flight Manual (RFM). This action

also requires, within 180 days, replacing the yoke assembly with a

zero-hours TIS airworthy yoke assembly, or one that has passed an x-ray

diffraction inspection. A frangible tail rotor flapping stop/yield

indicator, P/N 214-011-809-109, must also be installed. Further, this

AD requires a repetitive 25 hours time-in-service (TIS) inspection to

detect tail rotor flapping stop damage due to a hard landing, sudden

stoppage, or miscellaneous power on/off incidents, and an inspection

after each incident in which damage due to a hard landing, sudden

stoppage, or miscellaneous power on/off incidents may have occurred.

This amendment is prompted by reports of inflight failures of yokes

installed on civilian and military helicopters of similar type design.

The actions specified in this AD are intended to prevent fatigue

failure of the yoke that could result in loss of the tail rotor and

subsequent loss of control of the helicopter.

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

Bulletin No. 214ST-96-75, dated August 26, 1996, which specifies an

immediate, temporary reduction in the maximum airspeed, installing a

cockpit placard for this limitation, and incorporating a temporary RFM

supplement until the yoke historical records are researched for

previous damage history; until an x-ray diffraction inspection is

performed on the yoke to detect fatigue damage; and until a frangible

tail rotor flapping stop/yield indicator, P/N 214-011-809-109, is

installed. A repetitive 25 hour TIS inspection to detect damaging tail

rotor flapping stop contact due to a hard landing, sudden stoppage, or

miscellaneous power on/off incidents has been added.

Since an unsafe condition has been identified that is likely to

exist or develop on other BHTI Model 214ST helicopters of the same type

design, this AD is being issued to prevent fatigue failure of the yoke

due to external bending forces, which could result in failure of the

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

of the helicopter. The actions are required to be accomplished in

accordance with the service bulletin described previously. The short

compliance time involved is required because the previously described

critical unsafe condition can adversely affect the controllability of

the helicopter. Therefore, the actions stated in the AD are required

prior to further flight, 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 14 helicopters will be affected by this

proposed AD, that it will take approximately 9 work hours to accomplish

the inspections and installations, and that the average labor rate is

$60 per work hour. Required parts will cost approximately $21,844 for

the yoke, and $936 for the flapping stop, per helicopter. Based on

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

estimated to be $326,480 to replace the yoke and flapping stop in the

entire fleet.

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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-27-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 99-04-13 Bell Helicopter Textron, Inc.: Amendment 39-11037.

Docket No. 98-SW-27-AD.

Applicability: Model 214ST helicopters, serial numbers 28101 and

higher, 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 as indicated, unless accomplished

previously.

To prevent fatigue failure of the tail rotor yoke (yoke) that

could result in loss of the tail rotor and subsequent loss of

control of the helicopter, accomplish the following:

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

yoke assembly, part number (P/N) 214-011-802-105 or 214-011-802-111,

for any recorded static or dynamic incidents that could have imposed

a bending load on the yoke, but did not require yoke assembly

replacement; for example, an incident in which a damaged tail rotor

blade was replaced due to a blade strike. If such a history exists,

replace the yoke assembly with an airworthy yoke assembly.

(b) Before further flight, unless paragraph (c) of this AD has

been accomplished previously:

(1) Install a Never Exceed Velocity (Vne) red line at 145 knots

indicated airspeed (KIAS) on the pilot and copilot airspeed

indicators using red tape or paint, and a slippage indicator on the

instrument case and glass.

(2) Install a placard made of material that is not easily

erased, disfigured, or obscured on the instrument panel in clear

view of the pilot and copilot: ``Observe temporary Maximum Never

Exceed (Vne) airspeed red line (marked at 145 knots indicated

airspeed (KIAS)). Basic Vne is 15 KIAS less than that determined by

the Air Data Computer (ADC) but never less than 70 KIAS.''

(3) Insert the Bell Helicopter Textron 214ST Temporary Revision

for Airspeed Restriction, dated August 16, 1996, which is attached

to Bell Helicopter Textron Alert Service Bulletin No. 214ST-96-75,

dated August 26, 1996 (ASB) into the Limitations section of the

Model 214ST Rotorcraft Flight Manual (RFM).

(c) Within 180 calendar days after the effective date of this

AD:

(1) Remove yoke assembly, P/N 214-011-802-105 or 214-011-802-

111, and replace it with an airworthy yoke assembly, P/N 214-011-

802-105 or 214-011-802-111, with zero hours time-in-service (TIS),

or an airworthy yoke (regardless of TIS) that has passed a one-time

x-ray diffraction inspection in accordance with the ASB.

(2) Install an airworthy tail rotor flapping stop, P/N 214-011-

809-109.

(3) After the requirements of paragraphs (c)(1) and (c)(2) of

this AD are accomplished, remove the 145 KIAS redline from the pilot

and copilot airspeed indicators, remove the Vne airspeed restriction

placard, and remove the Bell Helicopter Textron 214ST Temporary

Revision for Airspeed Restriction, dated August 16, 1996, from the

RFM.

(d) After accomplishing paragraph (c) of this AD, inspect the

yoke assembly and tail rotor flapping stop in accordance with Part

III, Recurring 25 Hour Inspection and Conditional Inspection

Requirement, of the ASB:

--at intervals not to exceed 25 hours TIS; and

--before further flight after each incident in which there could

have been imposed a bending load on the yoke as referenced in

paragraph (a).

(e) 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

[[Page 7773]]

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 actions shall be done in accordance with Bell Helicopter

Textron Alert Service Bulletin No. 214ST-96-75, dated August 26,

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, 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 March 4, 1999.

Issued in Fort Worth, Texas, on February 5, 1999.

Eric Bries,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.

[FR Doc. 99-3590 Filed 2-16-99; 8:45 am]

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