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

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 94-SW-26-AD]

Airworthiness Directives; Bell Helicopter Textron, Inc. Model

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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing

airworthiness directive (AD), applicable to Bell Helicopter Textron,

Inc. (BHTI) Model 214B, 214B-1, and 214ST helicopters, that currently

establishes a mandatory retirement life of 60,000 high-power events for

the main transmission upper planetary carrier (carrier). This action

would require changing the method of calculating retirement life for

the carrier from high-power events to a maximum accumulated Retirement

Index Number (RIN) of 120,000. This proposal is prompted by fatigue

analyses and tests that show certain carriers fail sooner than

originally anticipated because of the unanticipated high number of

lifts or takeoffs (torque events) performed with those carriers in

addition to the time-in-service (TIS) accrued under other operating

conditions. The actions specified by the proposed AD are intended to

prevent fatigue failure of the carrier, which could result in failure

of the main transmission and subsequent loss of control of the

helicopter.

DATES: Comments must be received by March 17, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

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

Rules Docket No. 94-SW-26-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.

FOR FURTHER INFORMATION CONTACT: Mr. Uday Garadi, Aerospace Engineer,

FAA, Rotorcraft Directorate, Rotorcraft Certification Office, Fort

Worth, Texas 76193-0170, telephone (817) 222-5157, fax (817) 222-5959.

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 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. 94-SW-26-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. 94-SW-26-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas

76137.

Discussion

On June 6, 1994, the FAA issued AD 94-02-05, Amendment 39-8803, (59

FR 32325, June 23, 1994), to require changing the method of calculating

the retirement life for the carrier, part number (P/N) 214-040-077-007

and -101, from flight hours to high-power events calculated using the

number of takeoffs and external load lifts, removing the 2,500 hours

TIS magnetic particle inspection for the carrier, and making the

requirements applicable to the Model 214ST as well as the Model 214B

and 214B-1 helicopters. That action was prompted by fatigue analyses

and tests that show certain carriers fail sooner than originally

anticipated because of the unanticipated high number of lifts and

takeoffs (torque events) performed with those carriers in addition to

the TIS accrued under other operating conditions. The requirements of

that AD are intended to prevent fatigue failure of the carrier, which

could result in failure of the main transmission and subsequent loss of

control of the helicopter.

Since the issuance of that AD, BHTI has issued BHTI Information

Letter GEN-94-54, dated April 15, 1994, Subject: Retirement Index

Number (RIN) For Cycle Lifed Components, which introduces a different

method of accounting for fatigue damage on components that have

shortened service lives as a result of frequent torque events.

Additionally, BHTI has issued BHTI Alert Service Bulletin (ASB) 214-94-

52, which is applicable to Model 214B helicopters, and ASB 214ST-94-66,

which is applicable to Model 214ST helicopters, both of which are dated

November 7, 1994, and describe procedures for converting flight hours

and total number of torque events into a RIN for the carrier, P/N214-

040-077-007 and -101. Although ASB 214-94-52 does not state that it

applies to Model 214B-1 helicopters, this was an oversight by the

manufacturer. That ASB was intended to apply to both Model 214B and

214B-1 helicopters.

Since an unsafe condition has been identified that is likely to

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

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

94-02-05 to require creation of a component history card using the RIN

system and a system for tracking increases to the accumulated RIN, and

establish a maximum accumulated RIN for the carrier of 120,000 at which

it must be retired.

The FAA estimates that 11 helicopters of U.S. registry would be

affected by this proposed AD, that it would take approximately (1) 48

work hours per helicopter to replace the affected part due to the new

method of determining the retirement life required by this AD; (2) 2

work hours per helicopter to create the component history card or

equivalent record (record); and (3) 10 work hours per helicopter to

maintain the record each year, and that the average labor rate is $60

per work hour. Required parts would cost approximately $29,516 per

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

proposed AD on U.S. operators is estimated to be $61,813 for the first

year and $60,713 for each subsequent year. These costs assume

replacement of the spider in one-sixth of the fleet each year, creation

and maintenance of the records for all the fleet the first year, and

creation of one-sixth of the fleet's records and maintenance of the

records for all the fleet each subsequent year.

The regulations proposed herein would not have substantial direct

effects on the States, on the relationship between the national

government and

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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 removing Amendment 39-8803 (59 FR

32325, June 23, 1994), and by adding a new airworthiness directive

(AD), to read as follows:

Bell Helicopter Textron, Inc. (BHTI): Docket No. 94-SW-26-AD.

Supersedes AD 94-02-05, Amendment 39-8803.

Applicability: Model 214B, 214B-1, and 214ST helicopters with

main transmission upper planetary carrier (carrier), part number (P/

N) 214-040-077-007 or -101, 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 (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 25 hours time-in-service (TIS) after

the effective date of this AD, unless accomplished previously.

To prevent fatigue failure of the carrier, which could result in

failure of the main transmission and subsequent loss of control of

the helicopter, accomplish the following:

(a) Create a component history card or equivalent record for the

upper planetary carrier (carrier), P/N 214-040-077-007 or -101.

(b) Determine and record the accumulated Retirement Index Number

(RIN) to date on the carrier as follows (if the multiplication

results in a fraction, round the results up to the next whole

number):

(1) For Model 214B or B-1 helicopters:

(i) Multiply the high-power event total to date by 2, or

(ii) If the actual operating hours are known, and:

(A) If the type of operation is internal load lift operations

only, multiply each operating hour by 7;

(B) If the type of operation involves any external load lift

operations and the number of external load lift operations is known,

use the table below and multiply the appropriate factor for the

average number of external load lift operations by the number of

actual operating hours:

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Average number of external load lift operations per hour Factor *

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0-2.00....................................................... 7

2.01-5.00.................................................... 7

5.01-16.00................................................... 14

16.01-27.00.................................................. 21

Above 27.00.................................................. 28

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* RIN = Factor x Actual Operating Hours.

(C) If the type of operation involves any external load lift

operations and the number of external load lift operations is

unknown, multiply each actual operating hour by 21; or

(D) If the type of operation is unknown, multiply each actual

operating hour by 21.

(iii) If the actual operating hours are unknown, assume 900

operating hours per calendar year. Prorate the assumed operating

hours for partial years.

(A) If the type of operation is internal only, multiply the

assumed operating hours by 7.

(B) If the type of operation involves any external load lift

operations and the number of external load lift operations is known,

use the table in paragraph (ii)(B) above and multiply the

appropriate factor for the average number of external load lift

operations by the number of assumed operating hours;

(C) If the type of operation involves any external load lift

operations and the number of external load lift operations is

unknown, multiply each assumed operating hour by 21.

(D) If the type of operation is unknown, multiply each assumed

operating hour by 21.

(2) For Model 214ST helicopters:

(i) Multiply the high-power event total to-date by 2, or

(ii) Multiply the factored flight hour total to-date by 12.

Note 2: BHTI Alert Service Bulletin (ASB) 214-94-52, which is

applicable to Model 214B helicopters, and ASB 214ST-94-66, which is

applicable to Model 214ST helicopters, both of which are dated

November 7, 1994, pertain to this subject.

(c) After compliance with paragraphs (a) and (b) of this AD, and

during each operation thereafter, maintain a count of each lift or

takeoff performed and at the end of each day's operations, increase

the accumulated RIN on the component history card or equivalent

record as follows:

(1) For Model 214B and 214B-1 helicopters,

(i) Increase the RIN by 1 for each takeoff.

(ii) Increase the RIN by 1 for each external load lift

operation; or, increase the RIN by 2 for each external load lift

operation in which the load is picked up at a higher elevation and

released at a lower elevation, and the difference in the elevation

between the pick up point and the release point is 200 feet or

greater.

(2) For Model 214ST helicopters,

(i) Increase the RIN by 2 for each takeoff.

(ii) Increase the RIN by 2 for each external load lift

operation; or, increase the RIN by 4 for each external load lift in

which the load is picked up at a higher elevation and released at a

lower elevation and the difference in elevation between the pick up

point and the release point is 200 feet or greater.

(d) Remove the carrier, P/N's 214-040-077-007 or -101, from

service on or before attaining an accumulated RIN of 120,000. The

carrier is no longer retired based upon flight hours. This AD

revises the Airworthiness Limitations section of the maintenance

manual by establishing a new retirement life for the carrier of

120,000 RIN.

(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,

FAA, 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.

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.

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Issued in Fort Worth, Texas, on January 7, 1997.

Eric Bries,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.

[FR Doc. 97-879 Filed 1-13-97; 8:45 am]

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