[Federal Register Volume 71, Number 123 (Tuesday, June 27, 2006)]
[Proposed Rules]
[Pages 36495-36498]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-10090]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-25192; Directorate Identifier 2006-NM-004-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model CL-600-2B19 (Regional 
Jet Series 100 & 440) Airplanes

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

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede an existing airworthiness 
directive (AD) that applies to certain Bombardier Model CL-600-2B19 
(Regional Jet Series 100 & 440) airplanes. The existing AD currently 
requires repetitive detailed and eddy current inspections of the main 
fittings of the main landing gears (MLG) to detect discrepancies, and 
related investigative/corrective actions if necessary. The existing AD 
also requires servicing the shock strut of the MLGs; inspecting the 
shock strut of the MLGs for nitrogen pressure, visible chrome 
dimension, and oil leakage; and servicing any discrepant strut. This 
proposed AD would require installing a new, improved MLG main fitting, 
which would terminate the repetitive inspection and servicing 
requirements of the existing AD. This proposed AD results from stress 
analyses that showed certain main fittings of the MLGs are susceptible 
to premature cracking, starting in the radius of the upper lug. We are 
proposing this AD to detect and correct premature cracking of the main 
fittings of the MLGs, which could result in failure of the fittings and 
consequent collapse of the MLGs during landing.

DATES: We must receive comments on this proposed AD by July 27, 2006.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to
http://dms.dot.gov and follow the instructions for sending your 
comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Bombardier, Inc., Canadair, Aerospace Group, P.O. Box 6087, 
Station Centre-ville, Montreal, Quebec H3C 3G9, Canada, for service 
information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT: Richard Beckwith, Aerospace Engineer, 
Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft 
Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New 
York 11590; telephone (516) 228-7302; fax (516) 794-5531.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed in the ADDRESSES section. Include the docket number ``Docket No. 
FAA-2006-25192; Directorate Identifier 2006-NM-004-AD'' at the 
beginning of your comments. We specifically invite comments on the 
overall regulatory, economic, environmental, and energy aspects of the 
proposed AD. We will consider all comments received by the closing date 
and may amend the proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review the DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
may visit http://dms.dot.gov.

Examining the Docket

    You may examine the 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 DOT 
street address stated in the ADDRESSES

[[Page 36496]]

section. Comments will be available in the AD docket shortly after the 
Docket Management System receives them.

Discussion

    On June 30, 2004, we issued AD 2004-14-16, amendment 39-13725 (69 
FR 41421, July 9, 2004) for certain Bombardier Model CL-600-2B19 
(Regional Jet Series 100 & 440) airplanes. That AD requires repetitive 
detailed and eddy current inspections of the main fittings of the main 
landing gears (MLG) to detect discrepancies, and related investigative/
corrective actions if necessary. That AD also requires servicing the 
shock strut of the MLGs; inspecting the shock strut of the MLGs for 
nitrogen pressure, visible chrome dimension, and oil leakage; and 
servicing any discrepant strut. That AD resulted from stress analyses 
that showed certain main fittings of the MLGs are susceptible to 
premature cracking, starting in the radius of the upper lug. We issued 
that AD to detect and correct premature cracking of the main fittings 
of the MLGs, which could result in failure of the fittings and 
consequent collapse of the MLGs during landing.

Actions Since Existing AD Was Issued

    Since we issued AD 2004-14-16, the manufacturer has designed a new 
MLG main fitting. Installing this new fitting terminates the inspection 
requirements currently mandated by AD 2004-14-16.

Other Relevant Rulemaking

    On October 22, 2001, we issued AD 2001-22-09, amendment 39-12488 
(66 FR 54658, October 30, 2001), for certain Bombardier Model CL-600-
2B19 series airplanes. That AD requires repetitive eddy current 
inspections for cracking of the MLG main fittings, and replacement with 
a new or serviceable MLG, if necessary. That AD also requires servicing 
the MLG shock struts; inspecting the MLG shock struts for nitrogen 
pressure, visible chrome dimension, and oil leakage; and performing 
corrective actions, if necessary. That AD was prompted by reports of 
premature failure of the MLG main fitting. We issued that AD to prevent 
failure of the MLG main fitting, which could result in collapse of the 
MLG upon landing. AD 2001-22-09 inspects MLG main fittings that are 
similar to those addressed by this proposed AD. AD 2001-22-09 is 
relevant to this proposed AD because we are considering superseding AD 
2001-22-09 with a new AD that would have the same terminating action as 
that in this proposed AD.
    On September 27, 2004, we issued AD 2004-20-09, amendment 39-13814 
(69 FR 59790, October 6, 2004), for certain Bombardier Model CL-600-
2B19 (Regional Jet Series 100 & 440) airplanes. That AD requires 
repetitive inspections for cracks, sealant damage, and corrosion of the 
main fittings of the MLG, and corrective actions if necessary. That AD 
was prompted by a report of a cracked main fitting of the MLG. We 
issued that AD to detect and correct fatigue cracking of the main 
fitting of the MLG and consequent failure of the main fitting, which 
could result in the collapse of the MLG. AD 2004-20-09 addresses the 
same unsafe condition on MLG main fittings that have different part 
numbers. AD 2004-20-09 is relevant to this proposed AD because we are 
considering superseding AD 2004-20-09 with a new AD that would have the 
same terminating action as that in this proposed AD.

Relevant Service Information

    Bombardier has issued Service Bulletin 601R-32-093, Revision B, 
dated July 14, 2005. The service bulletin describes procedures for 
replacing the main fitting of the MLG with a new main fitting having a 
new part number (P/N).
    Bombardier has also issued Alert Service Bulletin 601R-32-088, 
Revision A, dated June 16, 2005, including Appendices A, B, and C, 
dated February 20, 2003. The procedures in this service bulletin are 
essentially the same as those in Bombardier Service Bulletin 601R-32-
088, including Appendices A, B, and C, dated February 20, 2003, which 
was referenced as the appropriate source of service information for 
doing the actions in AD 2004-14-16. Revision A makes changes that do 
not affect the technical content of the service bulletin.
    Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition. Transport Canada 
Civil Aviation (TCCA), which is the airworthiness authority for Canada, 
mandated the service information and issued Canadian airworthiness 
directive CF-2003-09R1, dated September 21, 2005, to ensure the 
continued airworthiness of these airplanes in Canada.
    Bombardier Service Bulletin 601R-32-093 refers to Messier-Dowty 
Service Bulletin M-DT SB17002-32-25, Revision 1, dated October 17, 
2003, as an additional source of service information for replacing the 
main fittings.

FAA's Determination and Requirements of the Proposed AD

    This airplane model is manufactured in Canada and is type 
certificated for operation in the United States under the provisions 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. We have examined TCCA's findings, 
evaluated all pertinent information, and determined that AD action is 
necessary for airplanes of this type design that are certificated for 
operation in the United States.
    This proposed AD would supersede AD 2004-14-16 and retain the 
requirements of the existing AD. This proposed AD would also require 
replacing the main fitting of the MLG with a new main fitting having a 
new P/N. Doing this replacement would terminate the repetitive 
inspection and servicing requirements of AD 2004-14-16.

Differences Between the Proposed AD and the Canadian Airworthiness 
Directive

    Although the Canadian airworthiness directive specifies to report 
certain information to the manufacturer, and although that action was 
included in AD 2004-14-16, this proposed AD would not continue to 
require those reports. We find that the reports are no longer necessary 
because the purpose of the reports was to help identify and develop a 
terminating action for the repetitive inspections. That terminating 
action has been developed and is the subject of this proposed AD.
    Although the applicability of the Canadian airworthiness directive 
does not specify serial numbers (S/Ns) of the affected airplanes, we 
have included the affected S/Ns in this proposed AD for clarity.

Changes to Existing AD

    This proposed AD would retain certain requirements of AD 2004-14-
16. Since AD 2004-14-16 was issued, the AD format has been revised, and 
certain paragraphs have been rearranged. As a result, the corresponding 
paragraph identifiers have changed in this proposed AD, as listed in 
the following table:

[[Page 36497]]



                      Revised Paragraph Identifiers
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                                           Corresponding requirement in
      Requirement in AD 2004-14-16               this proposed AD
------------------------------------------------------------------------
Paragraph (a)...........................  Paragraph (f).
Paragraph (b)...........................  Paragraph (g).
Paragraph (c)...........................  Paragraph (h).
Paragraph (d)...........................  Paragraph (i).
Paragraph (e)...........................  Paragraph (j).
------------------------------------------------------------------------

    We have also revised this action to clarify the appropriate 
procedure for notifying the principal inspector before using any 
approved alternative method of compliance (AMOC) on any airplane to 
which the AMOC applies.

Costs of Compliance

    The following table provides the estimated costs for U.S. operators 
to comply with this proposed AD. There are approximately 278 airplanes 
of U.S. registry that would be affected by this proposed AD. The 
average labor rate is $80 per work hour.

                                                 Estimated Costs
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                                           Work
                Action                    hours      Parts        Cost per airplane            Fleet cost
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Inspections (required by AD 2004-14-            4       None  $320, per inspection      $88,960, per inspection
 16).                                                          cycle.                    cycle.
Replacement (new proposed action).....         46   $105,732  $109,412................  $30,416,436.
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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 proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 proposed 
regulation:
    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 proposed 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, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
removing amendment 39-13725 (69 FR 41421, July 9, 2004) and adding the 
following new airworthiness directive (AD):

Bombardier, Inc. (Formerly Canadair): Docket No. FAA-2006-25192; 
Directorate Identifier 2006-NM-004-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by July 27, 
2006.

Affected ADs

    (b) This AD supersedes AD 2004-14-16.

Applicability

    (c) This AD applies to Bombardier Model CL-600-2B19 (Regional 
Jet Series 100 & 440) airplanes, serial numbers 7003 and subsequent; 
certificated in any category; equipped with main landing gear (MLG) 
main fittings, part numbers (P/N) 601R85001-81 and 601R85001-82 
(Messier Dowty Incorporated P/Ns 17064-105 and 17064-106).

Unsafe Condition

    (d) This AD results from stress analyses that showed certain 
main fittings of the MLGs are susceptible to premature cracking, 
starting in the radius of the upper lug. We are issuing this AD to 
detect and correct premature cracking of the main fittings of the 
MLGs, which could result in failure of the fittings and consequent 
collapse of the MLGs during landing.

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.

Restatement of the Requirements of AD 2004-14-16

Detailed Inspection of Main Fittings of the MLGs

    (f) Before the accumulation of 2,500 total flight cycles on the 
MLGs, or within 250 flight cycles after August 13, 2004 (the 
effective date of AD 2004-14-16), whichever occurs later: Do a 
detailed inspection on the main fittings of the MLGs to detect 
discrepancies (i.e., linear paint cracks or lack of paint (paint 
peeling), any other paint damage, adhesion, paint bulging, or 
corrosion), in accordance with Part A of the Accomplishment 
Instructions of Bombardier Alert Service Bulletin (ASB) A601R-32-
088, dated February 20, 2003; or Bombardier ASB 601R-32-088, 
Revision A, dated June 16, 2005, including Appendices, A, B, and C, 
dated February 20, 2003. Repeat the inspection thereafter at 
intervals not to exceed 100 flight cycles until paragraph (k) of 
this AD is accomplished.

    Note 1: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally

[[Page 36498]]

supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as 
mirrors, magnifying lenses, etc., may be used. Surface cleaning and 
elaborate access procedures may be required.''

Related Investigative/Corrective Actions

    (g) If any discrepancy is detected during any inspection 
required by paragraph (f) of this AD, before further flight: Do the 
related investigative/corrective actions in accordance with Part B 
or F of the Accomplishment Instructions of Bombardier ASB A601R-32-
088, including Appendices A and C, dated February 20, 2003; or 
Bombardier ASB A601R-32-088, Revision A, dated June 16, 2005, 
including Appendices A, B, and C, dated February 20, 2003. If an 
eddy current inspection (a related investigative action specified in 
Part B) is used to confirm the detailed inspection findings, the 
next eddy current required by paragraph (h) of this AD must be 
conducted within 500 flight cycles after the eddy current inspection 
specified in this paragraph, and thereafter at intervals not to 
exceed 500 flight cycles until paragraph (k) of this AD is 
accomplished.

Eddy Current Inspection of Main Fittings of the MLGs

    (h) At the time specified in paragraph (f) of this AD, do an 
eddy current inspection on the main fittings of the MLGs to detect 
cracks in accordance with Part B of the Accomplishment Instructions 
of Bombardier ASB A601R-32-088, including Appendix A, dated February 
20, 2003; or Bombardier ASB A601R-32-088, Revision A, dated June 16, 
2005, including Appendixes, A, B, and C, dated February 20, 2003. 
Repeat the eddy current inspection thereafter at intervals not to 
exceed 500 flight cycles, until paragraph (k) of this AD is 
accomplished. If any crack is found, before further flight, replace 
the affected main fittings of the MLGs with new or serviceable 
fittings in accordance with paragraph E.(5) of Part B of the 
Accomplishment Instructions of the service bulletin or in accordance 
with paragraph (k) of this AD. If any crack is found after the 
effective date of this AD, do the replacement in accordance with 
paragraph (k) of this AD.

Servicing of Shock Struts

    (i) Before the accumulation of 2,500 total flight cycles on the 
MLGs, or within 500 flight cycles after August 13, 2004, whichever 
occurs later, service the shock strut of the MLGs in accordance with 
Part C or D, as applicable, of the Accomplishment Instructions of 
Bombardier ASB A601R-32-088, including Appendix B, dated February 
20, 2003; or Bombardier ASB A601R-32-088, Revision A, dated June 16, 
2005, including Appendices A, B, and C, dated February 20, 2003.

Shock Strut Inspection

    (j) Within 500 flight cycles after completing the servicing 
required by paragraph (i) of this AD, inspect the shock strut of the 
MLGs for nitrogen pressure, visible chrome dimension, and oil 
leakage in accordance with Part E of the Accomplishment Instructions 
of Bombardier ASB A601R-32-088, including Appendix B, dated February 
20, 2003; or Bombardier ASB A601R-32-088, Revision A, dated June 16, 
2005, including Appendices A, B, and C, dated February 20, 2003. 
Repeat the inspection thereafter at intervals not to exceed 500 
flight cycles, until paragraph (k) of this AD is accomplished. If 
the nitrogen pressure and visible chrome dimensions are found 
outside the limits (the service bulletin refers to the airplane 
maintenance manual as the source of defined limits) and/or oil 
leakage is found, before further flight, service the affected shock 
strut of the MLGs in accordance with Part C or D, as applicable, of 
the Accomplishment Instructions of the service bulletin.

New Requirements of This AD

Replacement

    (k) Within 39 months after the effective date of this AD: 
Replace the main fittings of the MLGs, P/Ns 601R85001-81 and 
601R85001-82 (Messier Dowty Incorporated P/Ns 17064-105 and 17064-
106), with new main fittings, P/Ns 601R85001-83 and 601R85001-84 
(Messier Dowty Incorporated P/Ns 17064-107 and 17064-108), in 
accordance with the Accomplishment Instructions of Bombardier 
Service Bulletin 601R-32-093, Revision B, dated July 14, 2005. Doing 
this replacement terminates all requirements of paragraphs (f), (g), 
(h), (i), and (j) of this AD.

    Note 2: Bombardier Service Bulletin 601R-32-093, Revision B, 
refers to Messier Dowty M-DT Service Bulletin SB17002-32-25, 
Revision 1, dated October 17, 2003, as an additional source of 
service information for replacing the main fittings.

Parts Installation

    (l) As of the effective date of this AD, no person may install a 
main fitting of the MLG, P/Ns 601R85001-81 and 601R85001-82 (Messier 
Dowty Incorporated P/Ns 17064-105 and 17064-106), on any airplane.

No Reporting Required

    (m) Although the Accomplishment Instructions of Bombardier ASB 
A601R-32-088, dated February 20, 2003; and ASB 601R-32-088, Revision 
A, dated June 16, 2005; specify to report certain information to the 
manufacturer, this AD does not include that action.

Actions Accomplished in Accordance With Previous Revisions of 
Service Bulletin

    (n) Actions accomplished before the effective date of this AD in 
accordance with the service bulletins listed in Table 1 of this AD 
are acceptable for compliance with the actions in paragraph (k) of 
this AD.

                                Table 1.--Previous Revisions of Service Bulletin
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      Bombardier Service Bulletin                 Revision level                           Date
----------------------------------------------------------------------------------------------------------------
601R-32-093............................  Original.......................  October 17, 2003.
601R-32-093............................  A..............................  September 21, 2004.
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Alternative Methods of Compliance (AMOCs)

    (o)(1) The Manager, New York Aircraft Certification Office 
(ACO), 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 Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.

Related Information

    (p) Canadian airworthiness directive CF-2003-09R1, dated 
September 21, 2005, also addresses the subject of this AD.

    Issued in Renton, Washington, on June 5, 2006.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E6-10090 Filed 6-26-06; 8:45 am]
BILLING CODE 4910-13-P