[Federal Register Volume 71, Number 143 (Wednesday, July 26, 2006)]
[Rules and Regulations]
[Pages 42254-42258]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 06-6472]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-18850; Directorate Identifier 2004-SW-19-AD; 
Amendment 39-14694; AD 2004-16-15 R1]
RIN 2120-AA64


Airworthiness Directives; Eurocopter France Model AS-365N2, AS 
365 N3, EC 155B, EC155B1, SA-365N, N1, and SA-366G1 Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment revises an existing airworthiness directive 
(AD) for Eurocopter France (Eurocopter) Model AS-365N2, AS 365 N3, EC 
155B, EC155B1, SA-365N, N1, and SA-366G1 helicopters that currently 
requires inspecting the main gearbox (MGB) base plate for a crack and 
replacing the MGB if a crack is found. This amendment increases the 
time intervals for inspecting the MGB base plate and includes minor 
editorial changes throughout the AD. This amendment is prompted by 
crack growth tests that indicate that the inspection intervals can be 
increased without affecting safety. The actions specified by this AD 
are intended to detect a crack in an MGB base plate and prevent failure 
of one of the MGB attachment points to the frame, which could result in 
severe vibration and subsequent loss of control of the helicopter.

[[Page 42255]]


DATES: Effective August 30, 2006.

ADDRESSES: You may get the service information identified in this AD 
from American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, 
Texas 75053-4005, telephone (972) 641-3460, fax (972) 641-3527.
    Examining the Docket: You may examine the docket that contains this 
AD, any comments, and other information on the Internet at http://dms.dot.gov, or at the Docket Management System (DMS), U.S. Department 
of Transportation, 400 Seventh Street, SW., Room PL-401, on the plaza 
level of the Nassif Building, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Ed Cuevas, Aviation Safety Engineer, 
FAA, Rotorcraft Directorate, Safety Management Group, Fort Worth, Texas 
76193-0111, telephone (817) 222-5355, fax (817) 222-5961.

SUPPLEMENTARY INFORMATION: On August 4, 2004, we issued AD 2004-16-15, 
Amendment 39-13771 (69 FR 51358, August 19, 2004), to require visually 
inspecting the MGB for a crack in the MGB base plate, part number (P/N) 
366A32-1062-03 or P/N 366A32-1062-06, close to the attachment hole 
using a 10x or higher magnifying glass. Stripping paint from the 
inspection area is also required, but only before the initial 
inspection. That action was prompted by the discovery of a crack in the 
MGB base plate of an MGB installed in a Model AS-365 N2 helicopter. The 
crack was located very close to the attachment points of one of the 
laminated pads, and it propagated to the inside of the MGB base plate 
and then continued into the MGB casing. That condition, if not 
detected, could result in failure of one of the MGB attachment points 
to the frame, which could result in severe vibration and subsequent 
loss of control of the helicopter.
    When we issued AD 2004-16-15, the cause of crack in the MGB base 
plate was still under investigation; therefore, we considered the 
previously issued AD to be interim action until the cause of the crack 
could be determined. The cause of the crack is still under 
investigation. However, since issuing AD 2004-16-15, crack growth tests 
have shown that the inspection intervals can be increased without 
affecting safety. We made this determination after Eurocopter conducted 
crack growth testing in laboratory bench tests. A cracked base plate 
was loaded with an alternating torque to simulate flight loading and 
cycles. Crack propagation speed was measured and assessed over a longer 
duration than the initial inspection interval and this resulted in 
extending the inspection intervals. The first inspection interval was 
determined using crack striations, which was a quick and conservative 
method used to ensure airworthiness and allow for timely issuance of 
service information by the manufacturer. Based on this additional 
information, a proposal to amend 14 CFR part 39 by revising AD 2004-16-
15, Amendment 39-13771 (69 FR 51358, August 19, 2004), for the 
specified Eurocopter model helicopters, was published in the Federal 
Register on May 2, 2006 (71 FR 25789). That action proposed to increase 
the time intervals between each required inspection and proposed to 
include minor editorial changes in the AD.
    The Direction G[eacute]n[eacute]rale de L'Aviation Civile (DGAC), 
the airworthiness authority for France, notified the FAA that an unsafe 
condition may exist on Eurocopter Model SA 365N, N1, SA 366 G1, AS 365 
N2, N3, EC 155 B, and B1 helicopters, all serial numbers. The DGAC 
advises that a crack was detected in the MGB base plate of an AS 365 N2 
helicopter. The crack was detected in the MGB base plate web, very 
close to the attachment of one of the laminated pads, and runs to the 
inside of the MGB base plate and then on the MGB casing. In time, the 
growth of the crack may lead to the loss of the transfer of rotor 
torque to the rotorcraft structure.
    Eurocopter has issued Alert Service Bulletin (ASB) No. 05.00.45 for 
Model AS365 N, N1, N2, and N3 helicopters; ASB No. 05.29 for Model 
SA366 G1 helicopters; and ASB No. 05A005 for Model EC155 B and B1 
helicopters. All of the ASBs are dated November 8, 2004 and supersede 
previously issued Eurocopter Alert Telex No. 05.00.45, No. 05.29, and 
No. 05A005, all dated February 5, 2004. The ASBs specify the same 
actions as the alert telexes--visually inspecting the MGB base plate 
for the absence of cracks, using a 10x magnifying glass to facilitate 
the crack inspection, and, if in doubt about the existence of a crack, 
inspecting for a crack using a dye-penetrant crack detection 
inspection. However, for the Eurocopter Model AS365 N, N1, N2, N3, and 
SA366 G1 helicopters, the 15-flying hour check for the MGB base plate 
that is specified in the alert telexes is replaced with check intervals 
not to exceed 55 flying hours. For the EC155 B and B1 helicopters, the 
check after the last flight of each day and without exceeding a 9-
flying hour check interval is replaced with check intervals not to 
exceed 15 flying hours.
    The DGAC classified ASB Nos. 05.00.45, 05.29, and 05A005 as 
mandatory and issued AD No. F-2004-023 R1, dated November 24, 2004, to 
ensure the continued airworthiness of these helicopters in France.
    These helicopter models are manufactured in France and are type 
certificated for operation in the United States under the provisions of 
14 CFR 21.29 and the applicable bilateral agreement. Pursuant to the 
applicable bilateral agreement, the DGAC has kept the FAA informed of 
the situation described above. We have examined the findings of the 
DGAC, reviewed all available information, and determined that AD action 
is necessary for products of these type designs that are certificated 
for operation in the United States.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were received on the 
proposal or the FAA's determination of the cost to the public. The FAA 
has determined that air safety and the public interest require the 
adoption of the rule as proposed. The actions specified by this AD are 
still considered to be interim until the cause of the cracking can be 
determined.
    We estimate that this AD will affect 142 helicopters of U.S. 
registry. The initial inspection will take about 0.5 work hour and each 
recurring inspection will take about 0.25 work hour. Replacing the MGB, 
if necessary, will take about 4 work hours. The average labor rate is 
$65 per work hour. It will cost approximately $25,000 to repair a 
cracked MGB base plate. Based on these figures, the total estimated 
cost impact of the AD on U.S. operators is $56,249, assuming that each 
of the 135 Model AS 365 and SA 366 helicopters are inspected 11 times 
(the initial inspection plus 10 recurring inspections) and each of the 
7 Model EC 155 helicopters are inspected 40 times (the initial 
inspection plus 39 recurring inspections), and one cracked MGB base 
plate is found requiring the repair and replacement of one MGB. This 
estimate also assumes that a replacement MGB will not need to be 
purchased while a previously-installed MGB is being repaired.

Regulatory Findings

    We have determined that this AD will not have federalism 
implications under Executive Order 13132. This AD will 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.
    For the reasons discussed above, I certify that the regulation:

[[Page 42256]]

    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. 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.
    We prepared an economic evaluation of the estimated costs to comply 
with this AD. See the DMS to examine the economic evaluation.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
subtitle VII, part A, subpart III, section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment

0
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

0
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]

0
2. Section 39.13 is amended by removing Amendment 39-13771 (69 FR 
51358, August 19, 2004), and by adding a new airworthiness directive 
(AD), Amendment 39-14694, to read as follows:

2004-16-15 R1 Eurocopter France: Amendment 39-14694. Docket No. FAA-
2004-18850; Directorate Identifier 2004-SW-19-AD. Revises AD 2004-
16-15, Amendment 39-13771.

Applicability

    Model AS-365N2, AS 365 N3, EC 155B, EC155B1, SA-365N, N1, and 
SA-366G1 helicopters with a main gearbox (MGB) base plate, part 
number (P/N) 366A32-1062-03 or P/N 366A32-1062-06, installed, 
certificated in any category.

Compliance

    Required as indicated in the following compliance table and 
before installing a replacement main gearbox (MGB).

                                                Compliance Table
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           For model . . .                     If . . .               Or if . . .              Or if . . .
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(1) SA-365N, N1 and SA-366G1           An MGB is installed      An MGB is installed      An MGB is installed
 helicopters.                           that has less than       that has 9,900 or more   that is overhauled or
                                        9,900 cycles and has     cycles and has never     repaired, before
                                        never been overhauled    been overhauled or       further flight, unless
                                        or repaired, on or       repaired, before         accomplished
                                        before accumulating      further flight, unless   previously, and
                                        9,900 cycles, unless     accomplished             thereafter, at
                                        accomplished             previously, and          intervals not to
                                        previously, and          thereafter, at           exceed 55 hours TIS.
                                        thereafter, at           intervals not to
                                        intervals not to         exceed 55 hours TIS.
                                        exceed 55 hours time-
                                        in-service (TIS).
(2) AS-365N2 and AS 365 N3             An MGB is installed      An MGB is installed      An MGB is installed
 helicopters.                           that has less than       that has 7,300 or more   that has been
                                        7,300 cycles and has     cycles and has never     overhauled or
                                        never been overhauled    been overhauled or       repaired, before
                                        or repaired, on or       repaired, before         further flight, and
                                        before accumulating      further flight, and      thereafter, at
                                        7,300 cycles, unless     thereafter, at           intervals not to
                                        accomplished             intervals not to         exceed 55 hours TIS.
                                        previously, and          exceed 55 hours TIS.
                                        thereafter, at
                                        intervals not to
                                        exceed 55 hours TIS.
(3) EC 155B and EC155B1 helicopters..  An MGB base plate is     An MGB base plate is
                                        installed that has       installed that has
                                        less than 2,600          2,600 or more cycles,
                                        cycles, no later than    before further flight,
                                        2,600 cycles, unless     unless accomplished
                                        accomplished             previously, and
                                        previously, and          thereafter, at
                                        thereafter, at           intervals not to
                                        intervals not to         exceed 15 hours TIS .
                                        exceed 15 hours TIS.
----------------------------------------------------------------------------------------------------------------
One cycle equates to one helicopter landing in which a landing gear touches the ground.

    To detect a crack in the MGB base plate and prevent failure of a 
MGB attachment point to the frame, which could result in severe 
vibration and subsequent loss of control of the helicopter, 
accomplish the following.
    (a) Before the initial inspection at the time indicated in the 
compliance table of this AD, strip the paint from area ``D'' on both 
sides (``B'' and ``C'') of the MGB base plate as depicted in Figure 
1 of this AD.

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[GRAPHIC] [TIFF OMITTED] TR26JY06.025

    (b) At the times indicated in the compliance table, inspect area 
``D'' of the MGB base plate for a crack using a 10x or higher 
magnifying glass. Area ``D'' to be inspected is depicted in Figure 1 
of this AD.

    Note 1: Eurocopter France Alert Service Bulletin (ASB) No. 
05.00.45 for Model AS365 N, N1, N2, and N3 helicopters, ASB No. 
05.29 for Model SA366 G1 helicopters, and ASB No. 05A005 for Model 
EC155 B and B1 helicopters, pertain to the subject of this AD. All 
three ASBs are dated November 8, 2004.

    (c) If a crack is found in a MGB base plate, remove and replace 
the MGB with an airworthy MGB before further flight.
    (d) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Contact the Manager, Safety Management Group, Rotorcraft 
Directorate, FAA, ATTN: Ed Cuevas, Fort Worth, Texas 76193-0111, 
telephone (817) 222-5355, fax (817) 222-5961, for information about 
previously approved alternative methods of compliance.
    (e) This amendment becomes effective on August 30, 2006.


[[Page 42258]]


    Note 2: The subject of this AD is addressed in Direction 
Generale de L'Aviation Civile (France) AD F-2004-023 R1, dated 
November 24, 2004.


    Issued in Fort Worth, Texas, on July 18, 2006.
Mark R. Schilling,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 06-6472 Filed 7-25-06; 8:45 am]
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