
[Federal Register: September 29, 2008 (Volume 73, Number 189)]
[Rules and Regulations]               
[Page 56454-56457]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr29se08-4]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0636; Directorate Identifier 2007-NM-324-AD; 
Amendment 39-15657; AD 2008-17-19]
RIN 2120-AA64

 
Airworthiness Directives; ATR Model ATR42-200, -300, and -320 
Airplanes

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

ACTION: Final rule.

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

SUMMARY: We are adopting a new airworthiness directive (AD) for the 
products listed above. This AD results from mandatory continuing 
airworthiness information (MCAI) originated by an aviation authority of 
another country to identify and correct an unsafe condition on an 
aviation product. The MCAI describes the unsafe condition as:

    One ATR 42-300 experienced a collapse of the Right (RH) Main 
Landing Gear (MLG) when taxiing, caused by failure of the side brace 
assembly. Investigations revealed a crack propagation that occurred 
from a corrosion pit, in a very high stressed area of the upper arm. 
* * *
* * * * *
The unsafe condition is cracking of the upper arms of the secondary 
side brace assemblies of the MLG, which could result in collapse of the 
MLG during

[[Page 56455]]

takeoff or landing, damage to the airplane, and possible injury to the 
flightcrew and passengers. We are issuing this AD to require actions to 
correct the unsafe condition on these products.

DATES: This AD becomes effective November 3, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of November 3, 
2008.

ADDRESSES: You may examine the AD docket on the Internet at http://
www.regulations.gov or in person at the U.S. Department of 
Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC.

FOR FURTHER INFORMATION CONTACT: Tom Rodriguez, Aerospace Engineer, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
227-1137; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an AD that would apply to the specified products. 
That NPRM was published in the Federal Register on June 10, 2008 (73 FR 
32659). That NPRM proposed to correct an unsafe condition for the 
specified products. The MCAI states:

    One ATR 42-300 experienced a collapse of the Right (RH) Main 
Landing Gear (MLG) when taxiing, caused by failure of the side brace 
assembly. Investigations revealed a crack propagation that occurred 
from a corrosion pit, in a very high stressed area of the upper arm. 
Dimensions of the corrosion pit were lower than the minimum defect 
size that can be detected by usual inspection means used during 
landing gear overhaul. The superseded EASA (European Aviation Safety 
Agency) Airworthiness Directive (AD) 2007-0112 was issued to require 
repetitive inspections on affected high stressed areas on MLG side 
brace assemblies for crack detection and to replace the affected 
side brace assembly if any defect was found.
    Since the issuance of [EASA] AD 2007-0112, a modification of 
[the] side brace upper arm has been developed as terminating action. 
However, production non-conformity of the inspection tool was 
discovered.
    In order to correct the discrepancy of the initial tool, new 
inspection tool components have been manufactured and the Service 
Bulletin (SB) Messier Dowty 631-32-191 has been updated to revision 
2 accordingly. This directive mandates re-inspection of MLG side 
brace assemblies previously inspected [in accordance with] revision 
1 of the Messier Dowty SB 631-32-191 and reduces the inspection 
interval initially proposed in [EASA] AD 2007-0112 in order to 
maintain the same level of confidence.
* * * * *
The unsafe condition is 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. You may obtain further 
information by examining the MCAI in the AD docket.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We received no comments on the NPRM or on the determination of 
the cost to the public.

Conclusion

    We reviewed the available data and determined that air safety and 
the public interest require adopting the AD as proposed.

Differences Between This AD and the MCAI or Service Information

    We have reviewed the MCAI and related service information and, in 
general, agree with their substance. But we might have found it 
necessary to use different words from those in the MCAI to ensure the 
AD is clear for U.S. operators and is enforceable. In making these 
changes, we do not intend to differ substantively from the information 
provided in the MCAI and related service information.
    We might also have required different actions in this AD from those 
in the MCAI in order to follow our FAA policies. Any such differences 
are highlighted in a NOTE within the AD.

Costs of Compliance

    We estimate that this AD will affect about 31 products of U.S. 
registry. We also estimate that it will take about 35 work-hours per 
product to comply with the basic requirements of this AD. The average 
labor rate is $80 per work-hour. Required parts will cost about $0 per 
product. Based on these figures, we estimate the cost of this AD to the 
U.S. operators to be $86,800, or $2,800 per product.

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 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 this AD:
    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 a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD docket.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Operations office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains the NPRM, the regulatory evaluation, 
any comments received, and other information. The street address for 
the Docket Operations office (telephone (800) 647-5527) is in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after receipt.

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:

[[Page 56456]]

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 FAA amends Sec.  39.13 by adding the following new AD:

2008-17-19 ATR--Gie Avions De Transport R[eacute]gional (Formerly 
Aerospatiale): Amendment 39-15657. Docket No. FAA-2008-0636; 
Directorate Identifier 2007-NM-324-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective November 
3, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to ATR Model ATR42-200, -300, and -320 
airplanes, certificated in any category; excluding airplanes on 
which ATR Modification 8463 has been done.

Subject

    (d) Air Transport Association (ATA) of America Code 32: Landing 
gear.

Reason

    (e) The mandatory continuing airworthiness information (MCAI) 
states:

    One ATR 42-300 experienced a collapse of the Right (RH) Main 
Landing Gear (MLG) when taxiing, caused by failure of the side brace 
assembly. Investigations revealed a crack propagation that occurred 
from a corrosion pit, in a very high stressed area of the upper arm. 
Dimensions of the corrosion pit were lower than the minimum defect 
size that can be detected by usual inspection means used during 
landing gear overhaul. The superseded EASA (European Aviation Safety 
Agency) Airworthiness Directive (AD) 2007-0112 was issued to require 
repetitive inspections on affected high stressed areas on MLG side 
brace assemblies for crack detection and to replace the affected 
side brace assembly if any defect was found.
    Since the issuance of [EASA] AD 2007-0112, a modification of 
[the] side brace upper arm has been developed as terminating action. 
However, production non-conformity of the inspection tool was 
discovered.
    In order to correct the discrepancy of the initial tool, new 
inspection tool components have been manufactured and the Service 
Bulletin (SB) Messier Dowty 631-32-191 has been updated to revision 
2 accordingly. This directive mandates re-inspection of MLG side 
brace assemblies previously inspected [in accordance with] revision 
1 of the Messier Dowty SB 631-32-191 and reduces the inspection 
interval initially proposed in [EASA] AD 2007-0112 in order to 
maintain the same level of confidence.
* * * * *
The unsafe condition is 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.

Actions and Compliance

    (f) For MLG side brace assemblies with part number (P/N) 
D22710000, without suffix ``-9'': Unless already done, do the 
following actions.
    (1) For airplanes on which the MLG side brace assemblies have 
not been inspected as of the effective date of this AD, in 
accordance with the Accomplishment Instructions of Messier-Dowty 
Service Bulletin 631-32-191, Revision 1, dated February 26, 2007: 
Perform the initial eddy current inspection for cracking of the MLG 
side brace, in accordance with the Accomplishment Instructions of 
Messier-Dowty Special Inspection Service Bulletin 631-32-191, 
Revision 2, dated August 30, 2007, at the applicable time specified 
in Table 1 of this AD. Unless otherwise specified, the flight cycles 
and times indicated in Table 1 of this AD must be interpreted as 
total flight cycles since overhaul, or time since overhaul, and as 
total flight cycles since new or time since manufacture for side 
brace assemblies that have not undergone any overhaul yet.

                        Table 1--Compliance Times
------------------------------------------------------------------------
 For a MLG side brace assembly with the
 total flight cycles since new or total
 flight cycles since overhaul specified    Do the initial inspection at
 below as of the effective date of this     the time specified below--
                  AD--
------------------------------------------------------------------------
More than 8,000 flight cycles..........  Within 500 flight cycles after
                                          the effective date of this AD.
5,000 or more total flight cycles, but   Within 1,000 flight cycles
 not more than 8,000 total flight         after the effective date of
 cycles.                                  this AD or before accumulating
                                          8,500 flight cycles, whichever
                                          occurs first.
Less than 5,000 flight cycles..........  Within 2,000 flight cycles
                                          after the effective date of
                                          this AD or before accumulating
                                          6,000 flight cycles, whichever
                                          occurs first.
------------------------------------------------------------------------

    (2) For airplanes on which the MLG side brace assemblies have 
been inspected as of the effective date of this AD, in accordance 
with the Accomplishment Instructions of Messier-Dowty Service 
Bulletin 631-32-191, Revision 1, dated February 26, 2007: Within 
1,000 flight cycles after the last inspection or within 200 flight 
cycles after the effective date of this AD, whichever occurs later, 
perform an eddy current inspection for cracking of the MLG side 
brace, in accordance with the Accomplishment Instructions of 
Messier-Dowty Special Inspection Service Bulletin 631-32-191, 
Revision 2, dated August 30, 2007.
    (3) After accomplishment of the inspection required by paragraph 
(f)(1) or (f)(2) of this AD, repeat the inspection at intervals not 
to exceed 2,600 flight cycles in accordance with the Accomplishment 
Instructions of Messier-Dowty Special Inspection Service Bulletin 
631-32-191, Revision 2, dated August 30, 2007.
    (4) If any crack is found during any inspection required by 
paragraphs (f)(1), (f)(2) and (f)(3) of this AD, before further 
flight, replace the affected side brace in accordance with the 
Accomplishment Instructions of Messier-Dowty Special Inspection 
Service Bulletin 631-32-191, Revision 2, dated August 30, 2007.
    (5) At the applicable time specified in paragraph (f)(5)(i) or 
(f)(5)(ii) of this AD: Inspect for cracking, corrosion, and defects 
of the MLG side brace assemblies with P/N D22710000, without suffix 
``-9'', in accordance with the Accomplishment Instructions of 
Messier-Dowty Service Bulletin 631-32-194, dated June 6, 2007.
    (i) For airplanes having side brace assemblies on which Messier-
Bugatti Service Bulletin 631-32-072 has not been incorporated: 
Before accumulating 16,000 total flight cycles or within 8 years 
after the effective date of this AD, whichever occurs first.
    (ii) For airplanes having side brace assemblies on which 
Messier-Bugatti Service Bulletin 631-32-072 has been incorporated: 
Before accumulating 19,000 total flight cycles or within 8 years 
after the effective date of this AD, whichever occurs first.
    (6) If no cracking, corrosion, or defect is found during any 
inspection required by paragraph (f)(5) of this AD, before further 
flight, modify and re-identify (by adding a suffix ``-9'' to P/N 
D22710000) the MLG side brace assemblies in accordance with the 
Accomplishment Instructions of ATR Service Bulletin ATR42-32-0092, 
dated June 25, 2007.
    (7) If any cracking, corrosion, or defect is found during any 
inspection required by paragraph (f)(5) of this AD, before further 
flight, replace the discrepant MLG side brace assembly with a 
modified and re-identified MLG side brace assembly in accordance 
with the Accomplishment Instructions of ATR Service Bulletin ATR42-
32-0092, dated June 25, 2007.

FAA AD Differences

    Note: This AD differs from the MCAI and/or service information 
as follows: Although the MCAI or service information allows further 
flight if a crack is found during compliance with the required 
inspections,

[[Page 56457]]

this AD requires that you repair the crack before further flight.

Other FAA AD Provisions

    (g) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, 
International Branch, ANM-116, Transport Airplane Directorate, FAA, 
has the authority to approve AMOCs for this AD, if requested using 
the procedures found in 14 CFR 39.19. Send information to ATTN: Tom 
Rodriguez, Aerospace Engineer, International Branch, ANM-116, 
Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, 
Washington 98057-3356; telephone (425) 227-1137; fax (425) 227-1149. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.
    (2) Airworthy Product: For any requirement in this AD to obtain 
corrective actions from a manufacturer or other source, use these 
actions if they are FAA-approved. Corrective actions are considered 
FAA-approved if they are approved by the State of Design Authority 
(or their delegated agent). You are required to assure the product 
is airworthy before it is returned to service.
    (3) Reporting Requirements: For any reporting requirement in 
this AD, under the provisions of the Paperwork Reduction Act, the 
Office of Management and Budget (OMB) has approved the information 
collection requirements and has assigned OMB Control Number 2120-
0056.

Related Information

    (h) Refer to MCAI EASA Airworthiness Directive 2007-0263, dated 
October 3, 2007, and the service information specified in Table 2 of 
this AD, for related information.

                                          Table 2--Service Information
----------------------------------------------------------------------------------------------------------------
            Service Bulletin                           Revision                              Date
----------------------------------------------------------------------------------------------------------------
ATR Service Bulletin ATR42-32-0092.....  Original...........................  June 25, 2007.
ATR Technical Instruction ATR42, ATR42-  Original...........................  February 5, 2007.
 07-01.
Messier-Dowty Service Bulletin 631-32-   Original...........................  June 6, 2007.
 194.
Messier-Dowty Special Inspection         2..................................  August 30, 2007.
 Service Bulletin 631-32-191.
----------------------------------------------------------------------------------------------------------------

Material Incorporated by Reference

    (i) You must use the service information specified in Table 3 of 
this AD to do the actions required by this AD, unless the AD 
specifies otherwise.

                                   Table 3--Material Incorporated by Reference
----------------------------------------------------------------------------------------------------------------
            Service Bulletin                           Revision                              Date
----------------------------------------------------------------------------------------------------------------
ATR Service Bulletin ATR42-32-0092.....  Original...........................  June 25, 2007.
Messier-Dowty Service Bulletin 631-32-   Original...........................  June 6, 2007.
 194.
Messier-Dowty Special Inspection         2..................................  August 30, 2007.
 Service Bulletin 631-32-191.
----------------------------------------------------------------------------------------------------------------

Messier-Dowty Special Inspection Service Bulletin 631-32-191, 
Revision 2, dated August 30, 2007, contains the following effective 
pages:


----------------------------------------------------------------------------------------------------------------
                Page No.                    Revision level shown on page              Date shown on page
----------------------------------------------------------------------------------------------------------------
1, 3, 8................................  2.................................  August 30, 2007.
2, 6, 7, 9, 10.........................  1.................................  February 26, 2007.
4, 5...................................  Original..........................  December 13, 2006.
----------------------------------------------------------------------------------------------------------------

    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact ATR, 
316 Route de Bayonne, 31060 Toulouse, Cedex 03, France.
    (3) You may review copies at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue SW., Renton, Washington; or at the 
National Archives and Records Administration (NARA). For information 
on the availability of this material at NARA, call (202) 741-6030, 
or go to: http://www.archives.gov/federal-register/cfr/ibr-
locations.html.

    Issued in Renton, Washington, on August 12, 2008.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-19365 Filed 9-26-08; 8:45 am]

BILLING CODE 4910-13-P
