[Federal Register Volume 64, Number 200 (Monday, October 18, 1999)]
[Rules and Regulations]
[Pages 56156-56158]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-26713]



[[Page 56156]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-SW-56-AD; Amendment 39-11371; AD 99-20-13]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This document publishes in the Federal Register an amendment 
adopting Airworthiness Directive (AD) 99-20-13, which was sent 
previously to all known U.S. owners and operators of Eurocopter Canada 
Ltd. Model BO 105 LS A-3 helicopters by individual letters. This AD 
requires, before further flight, creating a component log card or 
equivalent record and determining the age and number of flights on each 
tension-torsion (TT) strap. The AD also requires inspecting and 
removing, as necessary, certain unairworthy TT straps. This amendment 
is prompted by an accident in which a main rotor blade (blade) 
separated from a Eurocopter Deutschland GMBH Model MBB-BK 117 
helicopter because of fatigue failure of the TT strap. The Model MBB-BK 
117 and the Model BO 105 LS A-3 helicopters use the same part-numbered 
TT strap. The actions specified by this AD are intended to prevent 
failure of a TT strap, loss of a blade, and subsequent loss of control 
of the helicopter.

DATES: Effective November 2, 1999, to all persons except those persons 
to whom it was made immediately effective by Emergency Priority Letter 
AD 99-20-13, which contained the requirements of this amendment.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of November 2, 1999.
    Comments for inclusion in the Rules Docket must be received on or 
before December 17, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 99-SW-56-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137.
    The applicable service information 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, 2601 Meacham Blvd., Room 663, Fort Worth, Texas; or at the 
Office of the Federal Register, 800 North Capitol Street, NW., suite 
700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Charles Harrison, Aerospace Engineer, 
FAA, Rotorcraft Directorate, Rotorcraft Standards Staff, 2601 Meacham 
Blvd., Fort Worth, Texas 76137, telephone (817) 222-5128, fax (817) 
222-5961.

SUPPLEMENTARY INFORMATION: On September 24, 1999, the FAA issued 
Emergency Priority Letter AD 99-20-13, applicable to Eurocopter Canada 
Ltd. Model BO 105 LS A-3 helicopters, which requires, before further 
flight, creating a component log card or equivalent record and 
determining the age and number of flights on each TT strap. The AD also 
requires inspecting and removing, as necessary, certain unairworthy TT 
straps. That action was prompted by an accident in which a blade 
separated from a Eurocopter Deutschland GMBH Model MBB-BK 117 
helicopter resulting in three fatalities. The cause of the blade 
separation was a TT strap fatigue failure within the main rotor head. 
The Model MBB-BK 117 and the Model BO 105 LS A-3 helicopters use the 
same part-numbered TT strap. This condition, if not corrected, could 
result in failure of a TT strap, loss of a blade, and subsequent loss 
of control of the helicopter.
    The FAA has reviewed Eurocopter Canada 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 
specifies inspecting and replacing, as necessary, certain unairworthy 
TT straps. Transport Canada Civil Aviation (TCAA), which is the 
airworthiness authority for Canada, classified that ASB as mandatory 
and issued AD CF-99-24R1, dated September 22, 1999, applicable to Model 
BO 105 LS A-3 helicopters.
    This helicopter model is manufactured in Canada and is type 
certificated for operation in the United States under the provision 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, TCCA has kept the FAA informed of 
the situation described above. The FAA has examined the findings of 
TCCA, reviewed all available information, and determined that AD action 
is necessary for products of this type design that are certificated for 
operations in the United States.
    Since the unsafe condition described is likely to exist or develop 
on other Eurocopter Canada Ltd. Model BO 105 LS A-3 helicopters of the 
same type design, the FAA issued Emergency Priority Letter AD 99-20-13 
to prevent failure of a TT strap, loss of a blade, and subsequent loss 
of control of the helicopter. The AD requires, before further flight, 
creating a component log card or equivalent record and determining the 
age and number of flights on each TT strap. The AD also requires 
inspecting and removing, as necessary, certain unairworthy TT straps. 
The actions must be accomplished in accordance with the ASB described 
previously. The short compliance time involved is required because the 
previously described critical unsafe condition can adversely affect the 
structural integrity of the helicopter. Therefore, creating a component 
log card or equivalent record, determining the age and number of 
flights on each TT strap, and inspecting and removing, as necessary, 
certain unairworthy TT straps are required prior to further flight, and 
this AD must be issued immediately.
    Since it was found that immediate corrective action was required, 
notice and opportunity for prior public comment thereon were 
impracticable and contrary to the public interest, and good cause 
existed to make the AD effective immediately by individual letters 
issued on September 24, 1999 to all known U.S. owners and operators of 
Eurocopter Canada Ltd. Model BO 105 LS A-3 helicopters. These 
conditions still exist, and the AD is hereby published in the Federal 
Register as an amendment to section 39.13 of the Federal Aviation 
Regulations (14 CFR 39.13) to make it effective to all persons.
    The FAA estimates that 27 helicopters of U.S. registry will be 
affected by this AD, that it will take approximately 1 work hour to 
inspect the 4 TT straps on each helicopter; 15 work hours per 
helicopter to remove and replace the 4 TT straps, if necessary; and the 
average labor rate is $60 per work hour. Required parts will cost 
approximately $2,600 per TT strap ($10,400 per helicopter). Based on 
these figures, the total cost impact of the AD on U.S. operators is 
estimated to be $306,720; $1,620 to inspect each helicopter once and 
$305,100 to remove and replace the 4 TT straps on all helicopters.

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Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket No. 99-SW-56-AD.'' The postcard will be date stamped and 
returned to the commenter.
    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, may be obtained from the Rules Docket at the 
location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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 adding a new airworthiness directive 
to read as follows:

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

    Applicability: Model BO 105 LS A-3 helicopter, 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 (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 main rotor blade (blade) separation due to failure of 
a TT strap, 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 the helicopter and each 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. For the time-in-service (TIS) where the number of 
flights is unknown, multiply the number of hours TIS by 5 to 
determine the number of flights. If a TT strap has been previously 
used at any time on a Model BO 105 LS A-3 `SUPERLIFTER', BO-105 CB-
5, BO-105 CBS-5, BO-105 DBS-5, or any MBB-BK 117 series helicopter, 
multiply the 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.
    (4) Remove any TT strap from service that has either accumulated 
40,000 or more flights or has an age equal to or greater than 216 
months.
    (b) When a TT strap age is greater than or equal to 120 months 
and less than 216 months and has accumulated less than 40,000 
flights, inspect the TT strap in accordance with the 
``Accomplishment Instructions,'' paragraph 2.B.2., of Eurocopter 
Canada Alert Service Bulletin BO 105 LS A-3 No. ASB-BO 105 LS-10-10, 
dated September 1, 1999 (ASB), according to the following:
    (1) If the age is greater than or equal to 120 months but less 
than 132 months and has less than 35,200 flights, inspect the TT 
strap within the next 6 weeks. If the number of flights equals or 
exceeds 35,200, inspect the TT strap before further flight.
    (2) If the age is greater than or equal to 132 months but less 
than 144 months and has less than 30,400 flights, inspect the TT 
strap within the next 5 weeks. If the number of flights equals or 
exceeds 30,400, inspect the TT strap before further flight.
    (3) If the age is greater than or equal to 144 months but less 
than 156 months and has less than 25,600 flights, inspect the TT 
strap within the next 4 weeks. If the number of flights equals or 
exceeds 25,600, inspect the TT strap before further flight.
    (4) If the age is greater than or equal to 156 months but less 
than 168 months and has less than 20,800 flights, inspect the TT 
strap within the next 3 weeks. If the number of flights equals or 
exceeds 20,800, inspect the TT strap before further flight.
    (5) If the age is greater than or equal to 168 months but less 
than 180 months and has less than 16,000 flights, inspect the TT 
strap within the next 2 weeks. If the number of flights equals or 
exceeds 16,000, inspect the TT strap before further flight.
    (6) If the age is greater than or equal to 180 months but less 
than 216 months, inspect the TT strap before further flight.
    (c) If a defect is found as a result of the inspections of 
paragraph (b), remove the TT strap from service before further 
flight.
    (d) If no defect is found as a result of the inspection, a 
maximum of 1,000 flights or 12 months additional time is permitted 
on a one-time basis before the TT strap must be replaced, provided 
the limits of paragraph (a)(4) are not exceeded.
    (e) An alternative method of compliance or adjustment of the 
compliance time that

[[Page 56158]]

provides an acceptable level of safety may be used if approved by 
the Manager, Regulations Group, 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, Regulations Group, Rotorcraft Directorate.

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

    (f) Special flight permits may be issued for up to five flights 
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.
    (g) The TT strap inspections shall be done in accordance with 
paragraph 2.B.2. of the ``Accomplishment Instructions'' in 
Eurocopter Canada Alert Service Bulletin BO 105 LS A-3 No. ASB-BO 
105 LS-10-10, dated September 1, 1999. This incorporation by 
reference was approved by the Director of the Federal Register in 
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be 
obtained from American Eurocopter Corporation, 2701 Forum Drive, 
Grand Prairie, Texas 75053-4005, telephone (972) 641-3460, fax (972) 
641-3527. Copies may be inspected at the FAA, Office of the Regional 
Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, 
Texas; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.
    (h) This amendment becomes effective on November 2, 1999, to all 
persons except those persons to whom it was made immediately 
effective by Emergency Priority Letter AD 99-20-13, issued September 
24, 1999, which contained the requirements of this amendment.

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

    Issued in Fort Worth, Texas, on October 4, 1999.
Henry A. Armstrong,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 99-26713 Filed 10-15-99; 8:45 am]
BILLING CODE 4910-13-P