[Federal Register Volume 61, Number 240 (Thursday, December 12, 1996)]
[Proposed Rules]
[Pages 65367-65369]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-31523]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-SW-29-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 retirement life of 60,000 high-power events for the main 
rotor trunnion (trunnion). This proposal would require changing the 
method of calculating retirement life for the trunnion from high power 
events to a maximum accumulated Retirement Index Number (RIN). This 
proposal is prompted by fatigue analyses and tests that show certain 
trunnions fail sooner than originally anticipated because of the 
unanticipated higher number of lifts or takeoffs (torque events) 
performed with those trunnions 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 trunnion, 
which could result in loss of the main rotor and subsequent loss of 
control of the helicopter.

DATES: Comments must be received by February 10, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Assistant Chief Counsel, Attention: 
Rules Docket No. 94-SW-29-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., Attention: Product Support 
Department, P.O. Box 482, Fort Worth, Texas 76101.

FOR FURTHER INFORMATION CONTACT: Mr. Charles Harrison, Aerospace 
Engineer, FAA, Rotorcraft Certification Office, Rotorcraft Directorate, 
Fort Worth, Texas 76193-0170, telephone (817) 222-5447, 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-29-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.

[[Page 65368]]

94-SW-29-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

Discussion

    On July 20, 1994, the FAA issued AD 94-15-14, Amendment 39-8985 (59 
FR 40798, August 10, 1994), to require changing the method of 
calculating the retirement life for the trunnion, part number (P/N) 
214-010-230-101, from flight hours to high-power events calculated 
using the number of takeoffs and external load lifts. That action was 
prompted by fatigue analyses and tests that show certain trunnions fail 
sooner than originally anticipated because of the unanticipated high 
number of lifts and takeoffs (torque events) performed with those 
trunnions in addition to the time-in-service (TIS) accrued under other 
operating conditions. The requirements of that AD are intended to 
prevent fatigue failure of the trunnion, which could result in loss of 
the main rotor 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-
55, which is applicable to the Model 214B helicopters, and ASB 214ST-
94-70, which is applicable to the 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 
trunnion, P/N 214-010-230-101. Although ASB 214-94-55 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 
94-15-14 to require creation of a component history card using the RIN 
system; a system for tracking increases to the accumulated RIN; and 
would establish a maximum accumulated RIN for the trunnion of 120,000 
at which the trunnion must be removed from service.
    The FAA estimates that 8 helicopters of U.S. registry would be 
affected by this proposed AD, and that it would take: (1) 10 work hours 
to replace the affected trunnion 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 $11,000. Based on these 
figures, the total cost impact of the proposed AD on U.S. operators is 
estimated to be $17,360 for the first year and $16,520 for each 
subsequent year. These costs assume replacement of the trunnion in one 
helicopter each year, creation and maintenance of the records for all 
the fleet the first year, and creation of one helicopter'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 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 39-8985 (59 FR 
40798, August 10, 1994), and by adding a new airworthiness directive 
(AD), to read as follows:

Bell Helicopter Textron, Inc. (BHTI): Docket No. 94-SW-29-AD. 
Supersedes AD 94-15-14, Amendment 39-8985.

    Applicability: Model 214B, 214B-1, and 214ST helicopters, with 
main rotor trunnion (trunnion), part number (P/N) 214-010-230-101, 
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 trunnion, which could result 
in loss of the main rotor and subsequent loss of control of the 
helicopter, accomplish the following:
    (a) Create a component history card or an equivalent record for 
the trunnion, P/N 214-040-230-101.
    (b) Determine and record on a component history card or 
equivalent record the accumulated Retirement Index Number (RIN) to-
date on the trunnion by multiplying the accumulated high-power event 
total to-date by 2 or as follows:
    (1) For Model 214B, multiply the flight hour total to-date by 24 
(round up any resulting fraction to the next higher whole number), 
or
    (2) For Model 214ST, multiply the factored flight hour total to-
date by 24 (round up any resulting fraction to the next higher whole 
number).

    Note 2: BHTI Alert Service Bulletin (ASB) No. 214-94-55, which 
is applicable to Model 214B and 214 B-1 helicopters, and ASB No. 
214ST-94-70, which is applicable to Model 214ST helicopters, both 
dated November 7, 1994, pertain to this AD.

    (c) After complying with paragraphs (a) and (b) of this AD, 
during each operation thereafter, maintain a count of the number and 
type of external load lifts and the number of takeoffs performed 
and, at the end of each day's operations, increase the accumulated 
RIN on the component history card as follows:

[[Page 65369]]

    (1) For the Model 214B and 214B-1 helicopters,
    (i) Increase the RIN by 1 for each takeoff.
    (ii) Increase the RIN by 1 for each external lift, 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 elevation between the pickup point 
and the release point is 200 feet or greater.
    (2) For the 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 
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.
    (d) Remove the trunnion, P/N 214-010-230-101, from service on or 
before attaining an accumulated RIN of 120,000. The trunnion is no 
longer retired based upon flight hours. This AD revises the 
Airworthiness Limitation section of the maintenance manual by 
establishing a new retirement life for the trunnion 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.

    Issued in Fort Worth, Texas, on December 4, 1996.
Eric Briese,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 96-31523 Filed 12-11-96; 8:45 am]
BILLING CODE 4910-13-U