[Federal Register Volume 63, Number 128 (Monday, July 6, 1998)]
[Proposed Rules]
[Pages 36377-36379]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-17765]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-SW-23-AD]


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

ACTION: Supplemental notice of proposed rulemaking (SNPRM); reopening 
of comment period.

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SUMMARY: This document revises an earlier proposed airworthiness 
directive (AD), applicable to Bell Helicopter Textron, Inc. (BHTI) 
Model 214B and 214B-1 helicopters, that would have established a 
mandatory retirement life of 15,000 high-power events for the pillow 
block bearing bolts (bearing bolts). That proposal was prompted by 
fatigue analyses and tests that show certain bearing bolts fail sooner 
than originally anticipated because of the unanticipated high number of 
lifts and takeoffs (torque events) performed with those bearing bolts 
in addition to the time-in-service (TIS) accrued under normal operating 
conditions. This action revises the proposed rule by proposing the 
creation of a component history card using a Retirement Index Number 
(RIN) system, establishment of a system for tracking increases to the 
accumulated RIN, and establishment of a maximum accumulated RIN for the 
bearing bolts. The actions specified by this proposed AD are intended 
to prevent fatigue failure of the bearing bolts, which could result in 
failure of the main rotor system and subsequent loss of control of the 
helicopter.

DATES: Comments must be received on or before September 4, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 94-SW-23-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137. Comments may be inspected at this location

[[Page 36378]]

between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal 
holidays.

FOR FURTHER INFORMATION CONTACT: Mr. Harry Edmiston, Aerospace 
Engineer, FAA, Rotorcraft Directorate, Rotorcraft Certification Office, 
Fort Worth, Texas 76193-0170, telephone (817) 222-5158, fax (817) 222-
5961.

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-23-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 Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 94-SW-23-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137.

Discussion

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39), applicable to BHTI Model 214B and 214B-1 helicopters, was 
published in the Federal Register on May 3, 1993 (58 FR 35902; July 2, 
1993). That NPRM would have required changing the method of calculating 
the retirement life for the bearing bolts, part number (P/N) 20-057-12-
48D and P/N 20-057-12-50D, from flight hours to equivalent operating 
hours based on high-power events calculated using the number of 
takeoffs and external load lifts, or a maximum of 15,000 high power 
events, whichever occurred first. That NPRM was prompted by fatigue 
analyses and tests that show certain bearing bolts fail sooner than 
originally anticipated because of the unanticipated high number of 
lifts and takeoffs (torque events) performed with those bearing bolts 
in addition to the TIS accrued under normal operating conditions. That 
condition, if not corrected, could result in fatigue failure of the 
bearing bolts, which could result in failure of the main rotor system 
and subsequent loss of control of the helicopter.
    Since the issuance of that NPRM, 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-
54, dated November 7, 1994, which describes procedures for converting 
flight hours and total number of torque events into a RIN for the 
bearing bolts, P/N 20-057-12-48D.
    The FAA desires to implement a standardized system to account for 
the high power torque events and the retirement lives of these bearing 
bolts. Therefore, the FAA now proposes to require the RIN method of 
accounting for high power torque events. The proposed AD would require 
creation of a component history card using the RIN system; 
establishment of a system for tracking increases to the accumulated 
RIN; and establishment of a maximum accumulated RIN for the bearing 
bolts of 17,000 before they must be removed from service.
    Since this change expands the scope of the originally proposed 
rule, the FAA has determined that it is necessary to reopen the comment 
period to provide additional opportunity for public comment.
    The FAA estimates that 54 helicopters of U.S. registry would be 
affected by this proposed AD, and that it would take (1) 24 work hours 
per helicopter to replace the affected bearing bolts due to the new 
method of determining the retirement life; (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 $2,000 per helicopter. Based on 
these figures, the total cost impact of the proposed AD on U.S. 
operators is estimated to be $224,640 for the first year and $128,520 
for each subsequent year. These costs assume replacement of the bearing 
bolts in the fleet the first year, creation and maintenance of the 
records for all the fleet; and replacement of one-half of the fleet's 
bolts, creation of the records for one-half of the fleet, 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 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.

[[Page 36379]]

Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding a new airworthiness directive 
(AD), to read as follows:

Bell Helicopter Company, Inc. (BHTI): Docket No. 94-SW-23-AD.

    Applicability: Model 214B and 214B-1 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 25 hours time-in-service (TIS), 
unless accomplished previously.
    To prevent fatigue failure of the pillow block bearing bolts 
(bearing bolts), part number (P/N) 20-057-12-48D or -50D, which 
could result in failure of the main rotor system and subsequent loss 
of control of the helicopter, accomplish the following:
    (a) Create a Retirement Index Number (RIN) component history 
card or an equivalent record for the bearing bolts, P/N 20-057-12-
48D or -50D.
    (b) Calculate and record on the component history card the 
historical accumulated RIN for the bearing bolts as follows:
    (1) When the type of operation (internal or external load lift), 
actual flight hours, and number of external load lifts or takeoffs 
per hour are known, multiply the actual flight hours by the 
appropriate factor in the following table for external load lift 
operation:

------------------------------------------------------------------------
   Average No. of external load lift events per flight hour      Factor 
------------------------------------------------------------------------
0-2.00.......................................................        6.8
2.01-5.00....................................................       13.6
5.01-16.00...................................................       27.2
16.01-27.00..................................................       40.8
Above 27.00..................................................       54.4
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    When the type of operation is internal load and no external 
lifting is involved, each hour of actual operating time is equal to 
6.8 RIN.
    (2) When the actual flight hours on the bolts are known, but the 
type of operation (internal or external load lift) is unknown, 
multiply the actual flight hours by a factor of 40.8.
    (3) When the actual flight hours on the bolts are unknown, 
assume 75 flight hours per month.
    (4) When the flight hours on the bolts are assumed, but the type 
of operation (internal or external load lift) is known,
    (i) Multiply the number of flight hours assumed for internal 
load operations by a factor of 6.8.
    (ii) Multiply the number of flight hours assumed for external 
load operations by a factor of 40.8.
    (5) When the flight hours on the bolts are assumed and the type 
of operation (internal or external load lift) is unknown, multiply 
the assumed flight hours by a factor of 40.8.
    (c) After compliance with paragraphs (a) and (b) of this AD, 
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 bearing bolts component history card as 
follows:
    (1) Increase the RIN by 1 for each takeoff.
    (2) Increase the RIN by 1 for each external load lift, or 
increase the RIN by 2 for each external load operation in which the 
load is picked up at a higher elevation and released at a lower 
elevation and the difference in elevation between the pickup point 
and the release point is 200 feet or greater.

    Note 2: Bell Helicopter Textron, Inc. Alert Service Bulletin 
214-94-54, dated November 7, 1994, pertains to the subject of this 
AD.

    (d) Remove the bearing bolts from service on or before attaining 
an accumulated RIN of 17,000. The bearing bolts are no longer 
retired based upon flight hours. If any of the four bolts require 
replacement for any reason, then all four bolts must be replaced at 
that time. This AD revises the Airworthiness Limitations section of 
the maintenance manual by establishing a new retirement life for the 
bearing bolts of 17,000 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, 
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 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.

    Issued in Fort Worth, Texas, on June 23, 1998.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 98-17765 Filed 7-2-98; 8:45 am]
BILLING CODE 4910-13-P