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[Federal Register Volume 76, Number 214 (Friday, November 4, 2011)]
[Rules and Regulations]
[Pages 68306-68310]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-28360]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0031; Directorate Identifier 2010-NM-135-AD; 
Amendment 39-16860; AD 2011-23-09]
RIN 2120-AA64

Airworthiness Directives; Bombardier, Inc. Airplanes

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

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for 
Bombardier, Inc. Model CL-600-2C10 (Regional Jet Series 700, 701, & 
702), CL-600-2D15 (Regional Jet Series 705),

[[Page 68307]]

and CL-600-2D24 (Regional Jet Series 900) airplanes. 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:

    There have been two reported cases of failure of the MLG [main 
landing gear] piston axle, P/N [part number] 49203-3 or 49203-5, 
resulting from fretting between the inboard axle sleeve and axle 
thrust face, damage to the protective coating and consequent stress 
corrosion. In both cases, the MLG did not collapse.
* * * * *
    The unsafe condition is failure of the MLG, which could adversely 
affect the airplane's safe landing. We are issuing this AD to require 
actions to correct the unsafe condition on these products.

DATES: This AD becomes effective December 9, 2011.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of December 9, 
2011.

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: Andreas Rambalakos, Aerospace 
Engineer, Airframe and Mechanical Systems Branch, ANE-171, FAA, New 
York Aircraft Certification Office (ACO), 1600 Stewart Avenue, Suite 
410, Westbury, New York 11590; telephone (516) 228-7345; fax (516) 794-
5531.

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 January 25, 2011 (76 
FR 4264). That NPRM proposed to correct an unsafe condition for the 
specified products. The MCAI states:

    There have been two reported cases of failure of the MLG [main 
landing gear] piston axle, P/N [part number] 49203-3 or 49203-5, 
resulting from fretting between the inboard axle sleeve and axle 
thrust face, damage to the protective coating and consequent stress 
corrosion. In both cases, the MLG did not collapse.
    In order to avoid future axle failures, which could potentially 
result in gear collapse and collateral damage, this [Canadian] 
directive mandates repetitive visual inspection [for damage and 
corrosion of the protective coating] and repair, as necessary, of 
the MLG piston axles, P/N 49203-3 and 49203-5.

The unsafe condition is failure of the MLG, which could adversely 
affect the airplane's safe landing. 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 considered the comments received.

Request To Include Additional Piston Axle Part Numbers

    Comair, Inc. (Comair) requested that we revise paragraph (g) of the 
NPRM (76 FR 4264, January 25, 2011) to include MLG piston axles having 
P/Ns 49263-1 and 49263-3. Comair explained that it has been in contact 
with Goodrich regarding these part numbers. Comair expressed that 
Goodrich's response supports what Comair surmised from the Goodrich 
component maintenance manual (CMM) for P/N 49000, which was that P/Ns 
49263-1 and 49263-3 are a next higher assembly (NHA) part number 
consisting of a piston axle with a metering pin assembly installed. 
Comair stated that the Goodrich CMM for P/N 49000 uses the following 
nomenclature, ``Piston/Axle/Metering Pin Assy (Pre SB 32-45).''
    Comair also explained that there have been several instances where 
Comair has sent Goodrich Landing Gear Services a piston/axle having P/N 
49203-3 for repair. Comair stated that while the piston/axle was at 
Goodrich, a metering pin was installed.
    Comair expressed that when the piston/axle was returned, the 
authorized release certificate (Form One) only contained P/N 49263-1, 
and that Form One does not list the part number for the piston/axle and 
metering pin, only the higher assembly part number. Comair further 
explained that when they received the piston/axle back into stock, the 
part number had changed from 49203-3 to 49263-1, during the receiving 
process. Comair stated that, consequently, when the piston/axle is 
installed on the airplane, it shows that P/N 49263-1 is installed; 
therefore, as the NPRM is written, Comair asserted that the NPRM would 
not apply by part number. Comair suggested that if P/Ns 49203-3 and 
49203-5 exhibit an unsafe condition, then P/Ns 49263-1 and 49263-3 
should be considered to have the same fretting concern and the same 
unsafe condition.
    We agree, for clarification, to include MLG piston axles having P/
Ns 49263-1 and 49263-3, in a note in the final rule. It has also come 
to our attention that several operators failed to do the inspection 
because the MLG rework paperwork (Form One) from Goodrich only 
annotated piston/axle/metering pin assembly NHA having P/N 49263-1 or 
49263-3, while the NPRM only proposed to require inspection for MLG 
piston axles having P/N 49203-3 or 49203-5. While neither this AD nor 
Canadian AD CF-2010-15, dated May 13, 2010, require inspection for MLG 
piston axles having P/N 49263-1 or 49263-3, we want to avoid the 
possibility of an operator overlooking the intent of this final rule 
simply because the operator's overhaul paperwork is the only document 
that references the NHA part number. This change has been coordinated 
with Transport Canada Civil Aviation. We have revised this final rule 
to include new Note 2 to inform operators that MLG piston axles having 
P/N 49203-3 or 49203-5 that are installed on the airplane could be 
identified as having P/N 49263-1 or 49263-3. We have re-identified 
subsequent notes accordingly.

Request To Extend the Proposed Compliance Time

    Mesa Airlines (Mesa) requested that we revise the NPRM (76 FR 4264, 
January 25, 2011) to extend the proposed compliance time of 12 months 
for the initial inspection specified in paragraph (h)(1) of the NPRM to 
24 months. Mesa explained that its request is due to the number of 
applicable components, the size of its fleet, repair vendor capacity, 
and the turn time for the piston axle if needed.
    We disagree to extend the compliance time specified in paragraph 
(h)(1) of the final rule. In developing an appropriate compliance time 
for this action, we considered the urgency associated with the subject 
unsafe condition, the availability of required parts, and the practical 
aspect of accomplishing the required inspection within a period of time 
that corresponds to the normal scheduled maintenance for most affected 
operators. According to the manufacturer, an ample number of required 
parts will be available to modify the airplanes identified in the 
Applicability section of this final rule within the compliance time. In 
consideration of these items, we have determined that a 12-month 
compliance time for the initial inspection in paragraph (h)(1) of this 
final rule is appropriate. However, under the provisions of paragraph 
(l) of the final rule, we will consider requests for approval of an 
extension of the compliance time if sufficient data are submitted to 
substantiate that the new compliance time would provide an

[[Page 68308]]

acceptable level of safety. We have not changed the final rule in this 
regard.

Request To Add a Compliance Time for Proposed Terminating Action

    In its request to extend the proposed compliance time for the 
initial inspection, Mesa added the following statement, ``6,000 hrs. to 
terminate.'' Mesa did not provide any explanation for this request.
    From this statement, we infer that Mesa requested that we include a 
compliance time of 6,000 flight hours after the initial inspection for 
the terminating action required by paragraph (j) of the final rule. We 
disagree with adding a compliance time to paragraph (j) of the final 
rule. Mesa has not provided any justification for this request. 
Further, including an additional compliance time would necessitate 
additional rulemaking, and we do not consider that delaying this action 
until that time is warranted, since the actions required by this AD are 
adequate to ensure continued safety of the affected fleet. We have not 
changed the final rule in this regard.

Request To Add a Provision for Piston Axles That Require Overhaul

    Mesa also requested that we revise the NPRM (76 FR 4264, January 
25, 2011) to add a paragraph to paragraph (h) of the NPRM to allow for 
a provision for MLG piston axles which are scheduled for overhaul. Mesa 
suggested the following wording: ``(4) For any piston axle that has 
been in service more than 48 months, of the effective date of this AD 
and is due to be overhauled within 36 months of the effective date of 
this AD, must be complied with at schedule overhaul.''
    We disagree to include a provision for MLG axles which are 
scheduled for overhaul. Mesa has not provided any technical 
justification for this request. However, affected operators may request 
to allow for a provision for MLG piston axles which are scheduled for 
overhaul, under the provisions of paragraph (l) of this final rule by 
submitting data, substantiating that the change would provide an 
acceptable level of safety. We have not changed the final rule in this 
regard.

Request To Clarify Paragraph (i) of the NPRM (76 FR 4264, January 25, 
2011)

    Mesa also requested that we clarify paragraph (i) of the NPRM (76 
FR 4264, January 25, 2011). Mesa has not specified what aspect of the 
requirement it wants clarified, nor has it provided any reason for this 
request.
    We agree to clarify paragraph (i) in this comment section of this 
final rule. Paragraph (i) of this final rule states the compliance time 
for doing the inspections specified in paragraph (h) of this AD for 
airplanes that have the mark ``32-45'' in the MOD STATUS field on the 
piston axle nameplate, or for airplanes that have done one of the 
repair engineering orders listed in the service information in 
paragraph (i) of this AD; within the compliance times required in 
paragraph (i) of this AD, these airplanes do the inspection and repeat 
the inspection as required by paragraph (h) of this AD. We have also 
added paragraphs (i)(1), (i)(2), and (i)(3) to the final rule to 
clarify the compliance times for paragraph (i).

Clarification

    We have revised paragraph (g) of this final rule to clarify that 
the compliance times for doing the inspection required by paragraph (g) 
of this final rule are the same as the applicable compliance times 
specified in paragraphs (h) and (i) of this final rule.
    We have also added Note 3 to this final rule to clarify that the 
MCAI specifies to inspect only airplanes having certain serial numbers 
that are part of the MCAI applicability. Because the affected part 
could be rotated onto any of the airplanes listed in the applicability, 
this AD requires the inspection be done on all airplanes.

Conclusion

    We reviewed the available data, including the comments received, 
and determined that air safety and the public interest require adopting 
the AD with the change described previously. We determined that this 
change will not increase the economic burden on any operator or 
increase the scope of the AD.

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 380 products of U.S. registry. 
We also estimate that it will take about 22 work-hours per product to 
comply with the basic requirements of this AD. The average labor rate 
is $85 per work-hour. Based on these figures, we estimate the cost of 
this AD to the U.S. operators to be $710,600, or $1,870 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 (76 FR 4264, January 25, 
2011), the regulatory evaluation, any comments received, and other 
information. The street address for

[[Page 68309]]

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

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

2011-23-09 Bombardier, Inc.: Amendment 39-16860. Docket No. FAA-
2011-0031; Directorate Identifier 2010-NM-135-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective December 
9, 2011.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Bombardier, Inc. Model CL-600-2C10 
(Regional Jet Series 700, 701 & 702), CL-600-2D15 (Regional Jet 
Series 705), and CL-600-2D24 (Regional Jet Series 900) airplanes; 
certificated in any category.

    Note 1:  This AD is not applicable to piston axles having part 
number (P/N) 49203-7 or P/N 49203-9, which were installed in 
production on Bombardier, Inc. Model CL-600-2C10 airplanes having 
serial numbers (S/Ns) 10266 and subsequent; and Models CL-600-2D15 
and CL-600-2D24 airplanes having S/Ns 15155 and subsequent.

Subject

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

Reason

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

    There have been two reported cases of failure of the MLG [main 
landing gear] piston axle, P/N 49203-3 or 49203-5, resulting from 
fretting between the inboard axle sleeve and axle thrust face, 
damage to the protective coating and consequent stress corrosion. In 
both cases, the MLG did not collapse.
* * * * *
    The unsafe condition is failure of the MLG, which could 
adversely affect the airplane's safe landing.

Compliance

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

Inspection and Repair

    (g) At the applicable time in paragraph (h)(1), (h)(2), (h)(3) 
or (i) of this AD, inspect to determine whether the airplane has a 
main landing gear piston axle having P/N 49203-3 or 49203-5. A 
review of airplane maintenance records is acceptable in lieu of this 
inspection if the part number of the main landing gear piston axle 
can be conclusively determined from that review.

    Note 2:  Operators should be aware that the Goodrich authorized 
release certificate (Form One) provided for MLG piston axles 
following overhaul, refers to only the higher assembly P/N 49263-1 
or 49263-3; therefore, it is possible that MLG piston axles having 
P/N 49203-3 or 49203-5 that are installed on the airplane could be 
identified as having P/N 49263-1 or 49263-3.

    (h) Except as required by paragraph (i) of this AD, if, during 
the inspection required by paragraph (g) of this AD, the landing 
gear piston axle is determined to have P/N 49203-3 or 49203-5: At 
the applicable time specified in paragraph (h)(1), (h)(2), or (h)(3) 
of this AD, do a detailed inspection for corrosion and damage of the 
inboard and outboard piston axles, in accordance with the 
Accomplishment Instructions of Bombardier Service Bulletin 670BA-32-
023, Revision C, dated January 29, 2009. Before further flight, 
repair any corrosion or damage found, in accordance with the 
Accomplishment Instructions of Bombardier Service Bulletin 670BA-32-
023, Revision C, dated January 29, 2009. Within 30 months after the 
initial inspection, or within 12 months after the effective date of 
this AD, whichever occurs later, do the inspection specified in this 
paragraph; and repeat the inspection thereafter at intervals not to 
exceed 30 months.
    (1) For any piston axle that has been in service for 48 months 
or more as of the effective date of this AD: Inspect within 12 
months after the effective date of this AD.
    (2) For any piston axle that has been in service for 24 months 
or more, but less than 48 months, as of the effective date of this 
AD: Inspect within 24 months after the effective date of this AD.
    (3) For any piston axle that has been in service for less than 
24 months as of the effective date of this AD: Inspect within 36 
months after the effective date of this AD.
    (i) For airplanes that have mark ``32-45'' in the MOD STATUS 
field of the piston axle nameplate or that have incorporated one of 
the Bombardier repair engineering orders listed in paragraph 1.D. of 
Bombardier Service Bulletin 670BA-32-023, Revision C, dated January 
29, 2009: At the latest of the applicable times specified in 
paragraphs (i)(1), (i)(2), and (i)(3) of this AD, do the inspection 
specified in paragraph (h) of this AD and repeat the inspection 
thereafter at the time specified in paragraph (h) of this AD:
    (1) Within 30 months after marking ``32-45'' in the MOD STATUS 
field of the piston axle nameplate.
    (2) Within 30 months after incorporating one of the Bombardier 
repair engineering orders listed in paragraph 1.D. of Bombardier 
Service Bulletin 670BA-32-023, Revision C, dated January 29, 2009.
    (3) Within 12 months after the effective date of this AD.

Terminating Action

    (j) Installing a piston axle having P/N 49203-7 or P/N 49203-9 
on any airplane constitutes a terminating action for the 
requirements of paragraphs (h), (h)(1), (h)(2), and (h)(3) of this 
AD, for that airplane.

Credit for Actions Accomplished in Accordance With Previous Service 
Information

    (k) Inspections and repairs accomplished before the effective 
date of this AD according to any service bulletin specified in table 
1 of this AD, are considered acceptable for compliance with the 
corresponding inspections and repairs specified in paragraph (h) of 
this AD.

                       Table 1--Credit for Accomplishment of Previous Service Information
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              Document                              Revision                                Date
----------------------------------------------------------------------------------------------------------------
Bombardier Service Bulletin 670BA-32- Original............................  October 24, 2007.
 023.
Bombardier Service Bulletin 670BA-32- A...................................  January 7, 2008.
 023.
Bombardier Service Bulletin 670BA-32- B...................................  March 5, 2008.
 023.
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FAA AD Differences

    Note 3: This AD differs from the MCAI and/or service information 
as follows: The MCAI specifies to inspect only airplanes having 
certain serial numbers that are part of the MCAI applicability. 
Because the affected part could be rotated onto any of the airplanes 
listed in the applicability, this AD requires the inspection be done 
on all airplanes.

Other FAA AD Provisions

    (l) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, New 
York Aircraft Certification Office (ACO), ANE-170, FAA,

[[Page 68310]]

has the authority to approve AMOCs for this AD, if requested using 
the procedures found in 14 CFR 39.19. In accordance with 14 CFR 
39.19, send your request to your principal inspector or local Flight 
Standards District Office, as appropriate. If sending information 
directly to the ACO, send it to ATTN: Program Manager, Continuing 
Operational Safety, FAA, New York ACO, 1600 Stewart Avenue, Suite 
410, Westbury, New York, 11590; telephone (516) 228-7300; fax (516) 
794-5531. Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office. The AMOC approval letter must specifically 
reference this AD.
    (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.

Related Information

    (m) Refer to MCAI Canadian Airworthiness Directive CF-2010-15, 
dated May 13, 2010; and Bombardier Service Bulletin 670BA-32-023, 
Revision C, dated January 29, 2009; for related information.

Material Incorporated by Reference

    (n) You must use Bombardier Service Bulletin 670BA-32-023, 
Revision C, dated January 29, 2009, including Appendix A, Revision 
B, dated March 5, 2008, to do the actions required by this AD, 
unless the AD specifies otherwise.
    (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 
Bombardier, Inc., 400 C[ocirc]te-Vertu Road West, Dorval, 
Qu[eacute]bec H4S 1Y9, Canada; telephone (514) 855-5000; fax (514) 
855-7401; email thd.crj@aero.bombardier.com; Internet http://www.bombardier.com.
    (3) You may review copies of the service information at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, 
Washington. For information on the availability of this material at 
the FAA, call (425) 227-1221.
    (4) You may also review copies of the service information that 
is incorporated by reference 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/code_of_federal_regulations/ibr_locations.html.

    Issued in Renton, Washington, on October 21, 2011.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-28360 Filed 11-3-11; 8:45 am]
BILLING CODE 4910-13-P
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