```

[Federal Register Volume 65, Number 118 (Monday, June 19, 2000)]
[Proposed Rules]
[Pages 37924-37926]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-15425]

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-SW-68-AD]

Airworthiness Directives; Eurocopter Canada Ltd. Model BO 105 LS 
A-3 Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to Eurocopter Canada Ltd. 
Model BO 105 LS A-3 helicopters. That AD currently requires, before 
further flight, creating a component log card or equivalent record, and 
determining the calendar age and number of flights on each tension-
torsion (TT) strap, and inspecting and removing, as necessary, certain 
unairworthy TT straps. This action would establish a life limit for 
certain main rotor TT straps. This proposal is prompted by an accident 
in which a main rotor blade (blade) separated from a Eurocopter 
Deutschland GMBH (ECD) Model MBB-BK 117 helicopter due to fatigue 
failure of a TT strap. The same part-numbered TT strap is used on the 
Model BO 105 LS A-3 helicopters. The actions specified by this AD are 
intended to prevent fatigue failure of a TT strap, loss of a blade, and 
subsequent loss of control of the helicopter.

DATES: Comments must be received on or before August 18, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 99-SW-68-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137. You may also send comments electronically to 
the Rules Docket at the following address: [email protected]. 
Comments may be inspected at the Office of the Regional Counsel between 
9 a.m. and 3 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Charles Harrison, Aviation Safety 
Engineer, FAA, Rotorcraft Directorate, Rotorcraft Standards Staff, Fort 
Worth, Texas 76193-0110, telephone (817) 222-5128, 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 mailed 
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. 99-SW-68-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. 99-SW-68-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137.

Discussion

    On October 4, 1999, the FAA issued AD 99-20-13, Amendment 39-11371 
(64 FR 56156, October 18, 1999), applicable to Eurocopter Canada Ltd. 
Model BO 105 LS A-3 helicopters. That AD requires, before further 
flight, creating a component log card or

[[Page 37925]]

equivalent record and determining the calendar age and number of 
flights on each TT strap. AD 99-20-13 also requires inspecting and 
removing, as necessary, certain unairworthy TT straps. That action was 
prompted by an accident in which a blade separated from an ECD Model 
MBB-BK 117 helicopter due to fatigue failure of a TT strap. The same 
part-numbered TT strap is also used on the Eurocopter Canada Ltd. Model 
BO 105 LS A-3 helicopters. The requirements of that AD are intended to 
prevent failure of a TT strap, loss of a blade, and subsequent loss of 
control of the helicopter.
    Since the issuance of that AD, we have determined the need to 
establish a life limit for the TT strap. We have also determined that 
the graduated inspection criteria and TT strap lives specified in the 
current AD are no longer necessary after a life limit is established.
    Eurocopter Canada issued Alert Service Bulletin BO 105 LS A-3 No. 
ASB-BO 105 LS-10-10, dated September 1, 1999 (ASB). The ASB describes 
procedures for determining the total accumulated installation time and 
number of flights on each TT strap. The ASB also specifies inspecting 
and replacing, as necessary, certain unairworthy TT straps. Transport 
Canada Civil Aviation, the airworthiness authority for Canada, 
classified this ASB as mandatory and issued AD CF-99-24R1, dated 
September 22, 1999, applicable to the Eurocopter Canada Model BO 105 LS 
A-3 helicopters to ensure the continued airworthiness of these 
helicopters in Canada.
    Since an unsafe condition has been identified on the ECD Model MBB-
BK-117 that is likely to exist or develop on Eurocopter Canada Ltd., 
Model BO 105 LS A-3 helicopters registered in the United States, the 
proposed AD would require establishing a life limit for the TT straps 
of 120 months or 25,000 flights, whichever occurs first.
    The FAA estimates that 20 helicopters of U.S. registry would be 
affected by this proposed AD, that it would take approximately 16 work 
hours per helicopter to accomplish the proposed actions, and that the 
average labor rate is $60 per work hour. Required parts would cost 
approximately $10,400 per helicopter. Based on these figures, the total 
cost impact of the proposed AD on U.S. operators is estimated to be 
$227,200.
    The regulations proposed herein would not have a substantial direct 
effect 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, it 
is determined that this proposal does not have federalism implications 
under Executive Order 13132.
    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 39-11371 (64 FR 
56156, October 18, 1999), and by adding a new airworthiness directive 
(AD), to read as follows:

Eurocopter Canada Ltd.: Docket No. 99-SW-68-AD. Supersedes AD 99-20-
13, Amendment 39-11371, Docket No. 99-SW-56-AD.

    Applicability: Model BO 105 LS A-3 helicopters, with part number 
(P/N) 2604067 (Bendix) or J17322-1 (Lord) rotor tension torsion (TT) 
strap, 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 
otherwise 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 request approval for an 
alternative method of compliance in accordance with paragraph (d) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent fatigue failure of a TT strap, loss of a main rotor 
blade (blade), and subsequent loss of control of the helicopter, 
accomplish the following:
    (a) Before further flight,
    (1) Create a component log card or equivalent record for each TT 
strap.
    (2) Review the history of each helicopter and TT strap. 
Determine the age since initial installation on any helicopter (age) 
and the number of flights on each TT strap. Enter both the age and 
the number of flights for each TT strap on the component log card or 
equivalent record. When the number of flights is unknown, multiply 
the number of hours time-in-service (TIS) by 5 to determine the 
number of flights. If a TT strap has been previously used at any 
time on Model BO-105LS A-3 ``SUPER LIFTER'', BO-105 CB-5, BO-105 
CBS-5, BO-105 DBS-5, or any MBB-BK 117 series helicopter, multiply 
the total number of flights accumulated on those other models by a 
factor of 1.6 and then add that result to the number of flights 
accumulated on the helicopters affected by this AD.
    (3) Remove any TT strap from service if the total hours TIS or 
number of flights and age cannot be determined.
    (b) Remove any TT strap, P/N 2604067 or J17322-1, that has been 
in service 120 months since initial installation on any helicopter 
or accumulated 40,000 flights (a flight is a takeoff and a landing). 
Replace the TT strap with an airworthy TT strap.
    (c) This AD revises the Airworthiness Limitations Section of the 
maintenance manual by establishing a life limit for the TT strap, P/
N 2604067 and J17322-1, of 120 months or 40,000 flights, whichever 
occurs first.
    (d) 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, Regulations Group, 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, Regulations Group.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Regulations Group.

    (e) Special flight permits may be issued in accordance with 
Sec. 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.

    Note 3: The subject of this AD is addressed in Transport Canada 
Civil Aviation, Canada, AD CF-99-24R1, dated September 22, 1999.

[[Page 37926]]

    Issued in Fort Worth, Texas, on June 9, 2000.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 00-15425 Filed 6-16-00; 8:45 am]
BILLING CODE 4910-13-U
```