[Federal Register Volume 65, Number 49 (Monday, March 13, 2000)]
[Proposed Rules]
[Pages 13251-13253]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-6037]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-SW-65-AD]


Airworthiness Directives; Eurocopter Deutschland GMBH Model BO-
105CB-5 and BO-105CBS-5 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 Eurocopter Deutschland GMBH 
(ECD) Model BO-105CB-5 and BO-105CBS-5 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. This action would establish 
a life limit for certain main rotor TT straps. This proposal is 
prompted by a need to establish a life limit for certain TT straps 
because of an accident in which a main rotor blade (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 used on the ECD Model BO-105 
helicopters. The actions specified by this AD are intended to prevent 
fatigue failure, loss of a blade, and subsequent loss of control of the 
helicopter.

DATES: Comments must be received on or before May 12, 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-65-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137. Comments may be inspected at this location 
between 9 a.m. and 3 p.m., Monday through Friday, except Federal 
holidays.
    The service information referenced in the proposed rule may be 
obtained from American Eurocopter Corporation, 2701 Forum Drive, Grand 
Prairie, Texas 75053-4005, telephone (972) 641-3460, fax (972) 641-
3527. This information may be examined at the FAA, Office of the 
Regional Counsel, Southwest Region, Room 663, Fort Worth, Texas.

FOR FURTHER INFORMATION CONTACT: Charles Harrison, Aerospace 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

[[Page 13252]]

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. 99-SW-65-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-65-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137.

Discussion

    On November 10, 1999, the FAA issued AD 99-24-05, Amendment 39-
11429 (64 FR 62973, November 18, 1999), applicable to ECD Model BO-
105CB-5 and BO-105CBS-5 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. AD 99-24-05 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 ECD Model BO-105CB-5 and BO-105CBS-5 
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, the FAA has determined the need to 
establish a life limit for the TT strap. ECD has issued Alert Service 
Bulletin BO 105 No. ASB-BO 105-10-113, Revision 1, dated August 31, 
1999 (ASB), which specifies establishing a life limit. The ASB 
specifies that part number (P/N) 2604067 be renumbered as 117-14110 and 
P/N J17322-1 be renumbered as 117-14111. The ASB also specifies 
replacing TT strap, part number (P/N) 117-14110 and 117-14111, at 
intervals not to exceed 120 months after initial installation on any 
ECD Model BO-105CB-5, BO-105CBS-5, or MBB-BK 117 helicopter or every 
25,000 flights, whichever occurs first. The LBA classified this ASB as 
mandatory and issued AD 1999-289/2, dated September 1, 1999, to ensure 
the continued airworthiness of these helicopters in the Federal 
Republic of Germany.
    Since an unsafe condition has been identified on the MBB-BK-117 
that is likely to exist or develop on the ECD Model BO-105CB-5 and BO-
105CBS-5 helicopters, registered in the United States, the proposed AD 
would require establishing a life limit effective January 1, 2001, for 
the TT straps of 120 months or 25,000 flights, whichever occurs first.
    The FAA estimates that 200 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 
$2,272,200.
    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 39-11429 (64 FR 
62973, November 18, 1999), and by adding a new airworthiness directive 
(AD), to read as follows:

Eurocopter Deutschland GMBH: Docket No. 99-SW-65-AD. Supersedes AD 
99-24-05, Amendment 39-11429, Docket No. 99-SW-58-AD.

    Applicability: Model BO-105CB-5 and BO-105CBS-5 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 
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 (e) 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) On or before January 1, 2001, remove any TT strap, part 
number (P/N) 117-14110 or 117-14111, that has been in service 120 
months since initial installation or accumulated 25,000 flights (a 
flight is a takeoff and a landing), on any Model BO-105CB-5, BO-
105CBS-5, or MBB-BK-117 helicopter, and replace the TT strap with an 
airworthy TT strap.
    (b) Before further flight,
    (1) Create a component log card or equivalent record for each TT 
strap, P/N 2604067 or J17322-1, by:
    (i) Reviewing the history of each helicopter and TT strap.
    (ii) Determining the age since initial installation on any 
helicopter (age) and the number of flights on each TT strap.
    (A) To determine the initial number of flights on a TT strap if 
the time-in-service (TIS) is known and if the number of flights is 
unknown, multiply the total number of hours TIS by 5 to obtain the 
number of flights.
    (B) If a TT strap has been previously used at any time on Model 
BO-105 helicopters not affected by this AD, multiply the number of 
flights accumulated on those other models by a factor of 0.625 and 
add that result to the number of flights accumulated on the Model 
BO-105CB-5 and BO-105CBS-5 helicopters.

[[Page 13253]]

    (iii) Entering both the age and the number of flights on the 
component log card or equivalent record.
    (2) Remove any TT strap from service if:
    (i) The total hours TIS or number of flights and age cannot be 
determined, or
    (ii) The TT strap has either accumulated 25,000 or more flights 
or has an age equal to or greater than 120 months.
    (3) Inspect any TT strap with an age less than 120 months that 
has accumulated less than 25,000 flights in accordance with 
paragraph 2.B.2 of the ``Accomplishment Instructions,'' of 
Eurocopter Deutschland GMBH Alert Service Bulletin BO 105 No. ASB-BO 
105-10-113, Revision 1, dated August 31, 1999 (ASB).
    (i) If a defect is found, remove the TT strap from service.
    (ii) If no defect is found, reidentify TT strap P/N 2604067 or 
J17322-1 before installing in accordance with the ``Accomplishment 
Instructions,'' paragraph 2.B.1.2., of the ASB.
    (c) When any TT strap is replaced because of age, usage, or 
defect, before further flight, reidentify the main rotor head and TT 
straps in accordance with the ``Accomplishment Instructions,'' 
paragraph 2.B.1.2., of the ASB.
    (d) This AD revises the Airworthiness Limitations Section of the 
maintenance manual by establishing a life limit for the TT strap of 
120 months or 25,000 flights, whichever occurs first.
    (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, 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.

    (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.

    Note 3: The subject of this AD is addressed in the Luftfahrt 
Bundesamt (Federal Republic of Germany) AD 1999-289/2, dated 
September 1, 1999.


    Issued in Fort Worth, Texas, on March 6, 2000.
Henry A. Armstrong,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 00-6037 Filed 3-10-00; 8:45 am]
BILLING CODE 4910-13-U