[Federal Register Volume 61, Number 221 (Thursday, November 14, 1996)]
[Proposed Rules]
[Pages 58355-58356]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-29103]



[[Page 58355]]

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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-SW-36-AD]


Airworthiness Directives; Bell Helicopter Textron, a Division of 
Textron Canada Ltd. Model 206L, L-1, L-3, and L4 Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to Bell Helicopter Textron, A 
Division of Textron Canada Ltd. (BHTC) Model 206L, L-1, L-3, and L-4 
helicopters. This proposal would require creation of a component 
history card using a Retirement Index Number (RIN) system, establishing 
a system for tracking increases to the accumulated RIN, and a maximum 
accumulated RIN for certain main rotor masts (masts) and main rotor 
trunnions (trunnions). This proposal is prompted by fatigue analyses 
and tests that show certain masts and trunnions fail sooner than 
originally anticipated because of the unanticipated higher number of 
external load lifts and takeoffs (torque events) performed with those 
masts and 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 mast or trunnion, 
which could result in loss of the main rotor system and subsequent loss 
of control of the helicopter.

DATES: Comments must be received by January 13, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Assistant Chief Counsel, Attention: 
Rules Docket No. 95-SW-36-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, A Division of Textron Canada 
Ltd. 12,800 Rue de L'Avenir, Mirabel, Quebec, Canada J7J1R4, ATTN: 
Product Support Engineering Light Helicopters. This information may be 
examined at the FAA, Office of the Assistant Chief Counsel, 2601 
Meacham Blvd., Room 663, Fort Worth, Texas.

FOR FURTHER INFORMATION CONTACT: Mr. Jurgen Priester, Aerospace 
Engineer, Rotorcraft Certification Office, Rotorcraft Directorate, FAA, 
2601 Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5159, 
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. 95-SW36-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. 95-SW-36-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 
76137.

Discussion

    This notice proposes the adoption of a new airworthiness directive 
(AD) that is applicable to BHTC Model 206L, 206L-1, 206-L-3, and 206L-4 
helicopters. This proposal would require, within the next 100 hours 
TIS, creation of a component history card using the RIN system for 
certain masts and trunnions; and establishing a system for tracking 
increases to the accumulated RIN. The proposal also establishes a 
retirement life for trunnions, based solely on a RIN of 24,000 and a 
mast retirement life based on a maximum RIN of 44,000 or a maximum 
number of flight hours, whichever occurs first. Fatigue analyses and 
tests by the manufacturer show that certain masts and trunnions fail 
sooner than originally anticipated because of the unanticipated high 
number of external load lifts and takeoffs (torque events) performed 
with those masts and trunnions in addition to the TIS accrued under 
other operating conditions. This condition, if not corrected, could 
result in fatigue failure of the mast or trunnion, which could result 
in loss of the main rotor system and subsequent loss of control of the 
helicopter.
    Bell Helicopter Textron, Inc., the previous type certificate 
holder, has issued Alert Service Bulletin (ASB) 206L-94-99, Revision A, 
dated May 1, 1995, which specifies creation of a component history card 
within the next 100 hours TIS for Model 206L, 206L-1, 206L-3, and 206L-
4 helicopters. The ASB also describes an alternate retirement life of a 
maximum accumulated RIN of 24,000 for the trunnion, part number (P/N) 
206-011-120-103, and an alternate retirement life for the mast of a 
maximum accumulated RIN of 44,000 or a maximum number of hours TIS, 
whichever occurs first, as follows: 1,200 hours TIS for masts, P/N 206-
040-535-001; 1,800 hours TIS for masts, P/N 206-040-535-005; 5,000 
hours TIS for masts, P/N 206-040-535-101; and 5,000 hours TIS for 
masts, P/N 206-040-535-105.
    This helicopter model is type certificated for operation in the 
United States under the provisions of section 21.29 of the Federal 
Aviation Regulations (14 CFR 21.29) and the applicable bilateral 
airworthiness agreement. Pursuant to this bilateral airworthiness 
agreement, the Canada Airworthiness Authority has kept the FAA informed 
of the situation described above. The FAA has examined the findings of 
the Canada Airworthiness Authority, reviewed all available information, 
and determined that AD action is necessary for products of this type 
design that are certificated for operation in the United States.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other BHTC Model 206L, 206L-1, 206L-3, and 206L-4 
helicopters of the same type design registered in the United States, 
the proposed AD would require creation of a component history card 
using the RIN system, establishing a system for tracking increases to 
the accumulated RIN, and a maximum accumulated RIN for the trunnion of 
24,000 and a maximum accumulated RIN of 44,000 or a maximum number of 
hours TIS, whichever occurs first, for the mast as follows: 1,200 hours 
TIS for mast, P/N 206-040-535-001; 1,800

[[Page 58356]]

hours TIS for mast, P/N 206-040-535-005; 5,000 hours TIS for mast, P/N 
206-040-535-101; and 5,000 hours TIS for mast, P/N 206-040-535-105, 
before they must be retired. The actions would be required to be 
accomplished in accordance with the service bulletin described 
previously.
    The FAA estimates that 711 helicopters of U.S. registry would be 
affected by this proposed AD, that it would take approximately (1) 8 
work hours per helicopter to replace the mast and 10 work hours per 
helicopter to replace the 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); (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 $9,538 per mast and $2,083 per trunnion. 
Based on these figures, the total cost impact of the proposed AD on 
U.S. operators for the first year is estimated to be $2,016,989, and 
each subsequent year to be $1,945,889. These costs assume creation and 
maintenance of the records for all the fleet the first year, 
replacement of the mast and trunnion in one-sixth of the fleet each 
year, and creation of new records for that one-sixth 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.

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

Bell Helicopter Textron, a Division of Textron Canada Ltd.: Docket 
No. 95-SW-36-AD.

    Applicability: Model 206L, 206L-1, 206L-3, and 206L-4 
helicopters, with main rotor mast (mast), part number (P/N) 206-040-
535-001, -005, -101, or -105, installed, or main rotor trunnion 
(trunnion), P/N 206-011-120-103, 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 (f) 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 100 hours time-in-service after the 
effective date of this AD, unless accomplished previously.
    To prevent fatigue failure of the mast or trunnion, which could 
result in loss of the main rotor system and subsequent loss of 
control of the helicopter, accomplish the following:
    (a) Create a component history card or an equivalent record for 
the affected mast and trunnion.
    (b) Determine the accumulated Retirement Index Number (RIN) to 
date based on the number of takeoffs and external load lifts (torque 
events) for parts in service in accordance with paragraphs 1 and 2 
of the Accomplishment Instructions of Bell Helicopter Textron, Inc. 
Alert Service Bulletin (ASB) No. 206L-94-99, Revision A, dated May 
1, 1995. Record this accumulated RIN on the component history card.
    (c) After complying with paragraphs (a) and (b) of this AD, 
during each operation thereafter, maintain a count of the number 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 cards as follows:
    (1) For the trunnion,
    (i) Increase the RIN for the Model 206, 206L-1, and 206L-3 
helicopters by 1 for each torque event.
    (ii) Increase the RIN for the Model 206L-4 helicopters by 2 for 
each torque event.
    (2) For the mast, increase the RIN for the Model 206L, 206L-1, 
206L-3, and 206L-4 helicopters by 1 for each torque event.
    (d) Remove the trunnion from service on or before attaining the 
maximum accumulated RIN in accordance with Table 1 of the 
Accomplishment Instructions of Bell Helicopter Textron, Inc. ASB No. 
206L-94-99, Revision A, dated May 1, 1995.
    (e) Remove the mast from service on or before attaining the 
maximum accumulated RIN or the flight hour service life limit, 
whichever occurs first, in accordance with Table 2 of the 
Accomplishment Instructions of Bell Helicopter Textron, Inc. ASB No. 
206L-94-99, Revision A, dated May 1, 1995.
    (f) 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 compliance with this AD, if any, may be 
obtained from the Rotorcraft Certification Office.

    (g) 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 November 5, 1996.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 96-29103 Filed 11-13-96; 8:45 am]
BILLING CODE 4910-13-P