Airworthiness Directives; Aerospatiale Model ATR72 Airplanes

[Federal Register Volume 71, Number 58 (Monday, March 27, 2006)]
[Rules and Regulations]
[Pages 15024-15027]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 06-2849]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-21909; Directorate Identifier 2005-NM-059-AD; 
Amendment 39-14521; AD 2006-06-12]
RIN 2120-AA64


Airworthiness Directives; Aerospatiale Model ATR72 Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

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[[Page 15025]]

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Aerospatiale Model ATR72 airplanes. This AD requires a one-time 
general visual inspection for contamination of the surface of the upper 
arms of the main landing gear (MLG) secondary side brace assemblies; 
and repetitive eddy current inspections for cracking of the upper arms, 
and related specified and corrective actions if necessary. This AD also 
mandates eventual replacement of aluminum upper arms with steel upper 
arms, which would end the repetitive inspections. This AD results from 
two reports of rupture of the upper arm of the MLG secondary side brace 
due to fatigue cracking. We are issuing this AD to prevent cracking of 
the upper arms of the secondary side brace assemblies of the MLG, which 
could result in collapse of the MLG during takeoff or landing, damage 
to the airplane, and possible injury to the flightcrew and passengers.

DATES: This AD becomes effective May 1, 2006.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of May 1, 2006.

ADDRESSES: You may examine the AD docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility, U.S. 
Department of Transportation, 400 Seventh Street, SW., Nassif Building, 
Room PL-401, Washington, DC.
    Contact Aerospatiale, 316 Route de Bayonne, 31060 Toulouse, Cedex 
03, France, for service information identified in this AD.

FOR FURTHER INFORMATION CONTACT: Tom Rodriguez, Aerospace Engineer, 
International Branch, ANM-116, Transport Airplane Directorate, FAA, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-1137; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:

Examining the Docket

    You may examine the airworthiness directive (AD) docket on the 
Internet at http://dms.dot.gov or in person at the Docket Management 
Facility office between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays. The Docket Management Facility office 
(telephone (800) 647-5227) is located on the plaza level of the Nassif 
Building at the street address stated in the ADDRESSES section.

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to include an AD that would apply to certain Aerospatiale 
Model ATR72 airplanes. That NPRM was published in the Federal Register 
on July 21, 2005 (70 FR 42003). That NPRM proposed to require a one-
time general visual inspection for contamination of the surface of the 
upper arms of the main landing gear (MLG) secondary side brace 
assemblies; and repetitive eddy current inspections for cracking of the 
upper arms, and related specified and corrective actions if necessary. 
That NPRM also proposed to mandate eventual replacement of aluminum 
upper arms with steel upper arms, which would end the repetitive 
inspections.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comment received from 
one commenter.

Request To Change Number of U.S.-Registered Airplanes in Cost Section

    American Airlines asks that we change the estimated number of U.S.-
registered airplanes listed in the ``Costs of Compliance'' section of 
the NPRM, which specifies that there are about 18 airplanes of U.S. 
registry affected by the AD. American Airlines states that this number 
is incorrect because his airline operates 29 Model ATR72-212 airplanes 
and 12 Model ATR72-212A airplanes in the U.S. American Airlines 
suggests that the figure for airplanes of U.S. registry be changed to 
add these airplanes.
    We agree to change the estimated number of U.S. airplanes listed in 
the ``Costs of Compliance'' section of the AD. The purpose of that 
section is only to `estimate' the number of airplanes affected by the 
AD. When an NPRM is written, we obtain the total number of U.S-
registered airplanes from the Air Claims database, and that number 
frequently changes. The total number of U.S-registered airplanes is 
currently 53. We have changed the ``Costs of Compliance'' section 
accordingly.
    For clarification, the AD applies to Aerospatiale Model ATR72-101, 
-102, -201, -202, -211, -212, and -212A airplanes, certificated in any 
category; except airplanes that have received ATR Modification 5522 in 
production. We have made no change to the applicability specified in 
this AD.

Clarification of AMOC Paragraph

    We have revised paragraph (k) of this AD to clarify the appropriate 
procedure for notifying the principal inspector before using any 
approved AMOC on any airplane to which the AMOC applies.

Conclusion

    We have carefully reviewed the available data, including the 
comment that has been received, and determined that air safety and the 
public interest require adopting the AD with the changes described 
previously. These changes will neither increase the economic burden on 
any operator nor increase the scope of the AD.

Costs of Compliance

    This AD affects about 53 airplanes of U.S. registry.
    The initial and repetitive inspections take about 1 work hour per 
airplane, at an average labor rate of $65 per work hour. Based on these 
figures, the estimated cost of the inspections for U.S. operators is 
$3,445, or $65 per airplane, per inspection cycle.
    The replacement takes about 4 work hours per airplane (2 work hours 
per upper arm), at an average labor rate of $65 per work hour. Required 
parts cost about $4,948 per airplane ($2,474 per upper arm). Based on 
these figures, the estimated cost of the replacement for U.S. operators 
is $276,024, or $5,208 per airplane.

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.

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 this AD:

[[Page 15026]]

    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866;
    (2) Is not a ``significant rule'' under 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 a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD docket. See the ADDRESSES 
section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

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

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 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. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

2006-06-12 Aerospatiale: Amendment 39-14521. Docket No. FAA-2005-
21909; Directorate Identifier 2005-NM-059-AD.

Effective Date

    (a) This AD becomes effective May 1, 2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Aerospatiale Model ATR72-101, -102, -201, 
-202, -211, -212, and -212A airplanes, certificated in any category; 
except airplanes that have received ATR Modification 5522 in 
production.

Unsafe Condition

    (d) This AD was prompted by two reports of rupture of the upper 
arm of the main landing gear (MLG) secondary side brace assembly due 
to fatigue cracking. We are issuing this AD to prevent cracking of 
the upper arms of the secondary side brace assemblies of the MLG, 
which could result in collapse of the MLG during takeoff or landing, 
damage to the airplane, and possible injury to the flightcrew and 
passengers.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Inspections

    (f) At the latest of the times specified in paragraphs (f)(1), 
(f)(2), and (f)(3) of this AD: Accomplish a general visual 
inspection for contamination of the surface of the upper arms of the 
MLG secondary side brace assemblies, and an eddy current inspection 
for cracking of the upper arms by doing all the actions specified in 
Parts A and B of the Accomplishment Instructions of Messier-Dowty 
Special Inspection Service Bulletin 631-32-178, Revision 1, dated 
September 30, 2004. Repeat the eddy current inspection at intervals 
not to exceed 800 flight cycles until accomplishment of paragraph 
(h) of this AD.
    (1) Before the accumulation of 4,000 total flight cycles on the 
secondary side brace.
    (2) Before the accumulation of 800 flight cycles on the 
secondary side brace since overhauled.
    (3) Within 200 flight cycles after the effective date of this 
AD.

    Note 1: For the purposes of this AD, a general visual inspection 
is: ``A visual examination of an interior or exterior area, 
installation, or assembly to detect obvious damage, failure, or 
irregularity. This level of inspection is made from within touching 
distance unless otherwise specified. A mirror may be necessary to 
enhance visual access to all exposed surfaces in the inspection 
area. This level of inspection is made under normally available 
lighting conditions such as daylight, hangar lighting, flashlight, 
or droplight and may require removal or opening of access panels or 
doors. Stands, ladders, or platforms may be required to gain 
proximity to the area being checked.''

Related Specified and Corrective Actions

    (g) If any cracking is found during any inspection required by 
paragraph (f) of this AD: Before further flight, replace the 
affected upper arm of the MLG secondary side brace assembly as 
specified in paragraph (g)(1) or (g)(2) of this AD.
    (1) Replace the aluminum upper arm of the MLG secondary side 
brace assembly with a steel upper arm by doing the applicable 
actions specified in the Accomplishment Instructions of Messier-
Dowty Service Bulletin 631-32-183, dated October 6, 2004. This 
replacement ends the repetitive inspections required by paragraph 
(f) of this AD for that side brace only.
    (2) Replace the aluminum upper arm of the MLG secondary side 
brace assembly with a new or serviceable aluminum upper arm in 
accordance with a method approved by either the Manager, 
International Branch, ANM-116, Transport Airplane Directorate, FAA; 
or the Direction G[eacute]n[eacute]rale de l'Aviation Civile (or its 
delegated agent). ATR Component Maintenance Manual, Chapter 32-18-
41, Revision 3, dated September 30, 2002, is one approved method. 
Accomplish a general visual inspection for contamination of the 
surface of the upper arm before the accumulation of 4,000 total 
flight cycles on the replacement aluminum upper arm, and if cracks 
are found, before further flight, replace the aluminum upper arm 
with a steel upper arm as required by paragraph (g)(1) of this AD. 
If no cracks are found, repeat the eddy current inspection 
thereafter at intervals not to exceed 800 flight cycles until 
accomplishment of paragraph (h) of this AD.

Terminating Action

    (h) Replace all aluminum upper arms of the MLG secondary side 
brace assembly with steel upper arms by doing all the applicable 
actions in accordance with the Accomplishment Instructions of 
Messier-Dowty Service Bulletin 631-32-183, dated October 6, 2004; at 
the applicable time specified in paragraph (h)(1), (h)(2), (h)(3), 
or (h)(4) of this AD. Accomplishing this replacement ends the 
repetitive inspections required by paragraph (f) of this AD.
    (1) For airplanes on which any upper arm has been overhauled 
before the effective date of this AD and on which Messier-Bugatti 
Service Bulletin 631-32-085, dated August 21, 1992, has not been 
accomplished, as of the effective date of this AD: Within 15,000 
flight cycles or 96 months, whichever is first, since overhaul on 
the affected upper arm.
    (2) For airplanes on which any upper arm has been overhauled 
before the effective date of this AD and on which Messier-Bugatti 
Service Bulletin 631-32-085, dated August 21, 1992, has been 
accomplished, as of the effective date of this AD: Within 18,000 
flight cycles or 96 months, whichever is first, since overhaul on 
the affected upper arm.
    (3) For airplanes on which any upper arm has not been overhauled 
and on which Messier-Bugatti Service Bulletin 631-32-085, dated 
August 21, 1992, has not been accomplished, as of the effective date 
of this AD: Before the accumulation of 15,000 total flight cycles on 
an upper arm since new, or within 96 months on an upper arm since 
new, whichever is first.
    (4) For airplanes on which any upper arm has not been overhauled 
and on which Messier-Bugatti Service Bulletin 631-32-085, dated 
August 21, 1992, has been accomplished, as of the effective date of 
this AD: Before the accumulation of 18,000 total flight cycles on an 
upper arm since new, or within 96 months on an upper arm since new, 
whichever is first.

No Report Required

    (i) Messier-Dowty Special Inspection Service Bulletin 631-32-
178, Revision 1, dated September 30, 2004, recommends sending an 
inspection report to Messier-Dowty, but this AD does not contain 
that requirement.

Parts Installation

    (j) As of the effective date of this AD, no person may install, 
on any airplane, an aluminum upper arm of the MLG secondary side 
brace assembly, unless the applicable requirements specified in 
paragraphs (f) and (g) of this AD have been accomplished.

Alternative Methods of Compliance (AMOCs)

    (k)(1) The Manager, International Branch, ANM-116, Transport 
Airplane Directorate, FAA, has the authority to approve AMOCs for 
this AD, if requested in accordance with the procedures found in 14 
CFR 39.19.
    (2) Before using any AMOC approved in accordance with 14 CFR 
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the

[[Page 15027]]

FAA Flight Standards Certificate Holding District Office.

Related Information

    (l) French airworthiness directive F-2004-164, dated October 13, 
2004, also addresses the subject of this AD.

Material Incorporated by Reference

    (m) You must use Messier-Dowty Special Inspection Service 
Bulletin 631-32-178, Revision 1, dated September 30, 2004; and 
Messier-Dowty Service Bulletin 631-32-183, dated October 6, 2004; as 
applicable; to perform the actions that are required by this AD, 
unless the AD specifies otherwise. Messier-Dowty Special Inspection 
Service Bulletin 631-32-178, Revision 1, dated September 30, 2004, 
contains the following effective pages:

------------------------------------------------------------------------
                                  Revision level
            Page No.              shown  on page    Date shown on page
------------------------------------------------------------------------
1-3, 5-9.......................  1..............  Sept. 30, 2004.
4..............................  Original.......  May 3, 2004.
------------------------------------------------------------------------

    The Director of the Federal Register approved the incorporation 
by reference of these documents in accordance with 5 U.S.C. 552(a) 
and 1 CFR part 51. Contact Aerospatiale, 316 Route de Bayonne, 31060 
Toulouse, Cedex 03, France, for a copy of this service information. 
You may review copies at the Docket Management Facility, U.S. 
Department of Transportation, 400 Seventh Street, SW., Room PL-401, 
Nassif Building, Washington, DC; on the Internet at http://dms.dot.gov; or at the National Archives and Records Administration 
(NARA). For information on the availability of this material at the 
NARA, call (202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html html.

    Issued in Renton, Washington, on March 10, 2006.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 06-2849 Filed 3-24-06; 8:45 am]
BILLING CODE 4910-13-P

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