[Federal Register Volume 72, Number 141 (Tuesday, July 24, 2007)]
[Rules and Regulations]
[Pages 40224-40226]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-13983]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-25779; Directorate Identifier 2006-NM-088-AD; 
Amendment 39-15131; AD 2007-15-02]
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: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. 
This AD requires revising the Certification Maintenance Requirements 
and the Maintenance Review Board Report sections of the Canadair 
Regional Jet Maintenance Requirements Manual to include changes and 
additions to checks of the aileron power control units (PCUs) and a 
change to the interval of the backlash check of the aileron control 
system. This AD results from a report that data collected from in-
service airplanes show that approximately 19 percent of aileron 
backlash checks conducted at 4,000-flight-hour intervals reveal that 
aileron backlash wear limits are being exceeded. We are issuing this AD 
to prevent exceeded backlashes in both aileron PCUs, which, if 
accompanied by the failure of the flutter damper, could result in 
aileron vibration/flutter and reduced controllability of the airplane.

DATES: This AD becomes effective August 28, 2007.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of August 28, 
2007.

ADDRESSES: You may examine the AD docket on the Internet at http://dms.dot.gov or in person at the U.S. Department of Transportation, 
Docket Operations, M-30, West Building Ground Floor, Room W12-40, 1200 
New Jersey Avenue, SE., Washington, DC.
    Contact Bombardier, Inc., Canadair, Aerospace Group, P.O. Box 6087, 
Station Centreville, Montreal, Quebec H3C 3G9, Canada, for service 
information identified in this AD.

FOR FURTHER INFORMATION CONTACT: Daniel Parrillo, Aerospace Engineer, 
Systems and Flight Test Branch, ANE-172, FAA, New York Aircraft 
Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New 
York 11590; telephone (516) 228-7305; fax (516) 794-5531.

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 Operations 
office between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Operations office (telephone (800) 647-5527) is 
located on the ground floor of the West 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 all Bombardier Model 
CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. That NPRM was 
published in the Federal Register on September 11, 2006 (71 FR 53345). 
That NPRM proposed to require revising the Certification Maintenance 
Requirements and the Maintenance Review Board (MRB) Report sections of 
the Canadair Regional Jet Maintenance Requirements Manual (MRM) to 
include changes and additions to checks of the aileron power control 
units (PCUs) and a change to the interval of the backlash check of the 
aileron control system.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments received.

Request To Provide Additional Information on Selection of Check 
Interval

    The National Transportation Safety Board (NTSB) requests that we 
provide additional information in the final rule indicating how the 
repeat interval for the aileron backlash check was selected and why the 
interval will prevent flight

[[Page 40225]]

with aileron freeplay greater than the maximum limit. The NTSB notes 
that the Discussion section of the proposed AD does not explain how the 
2,000-flight-hour interval was selected or why it would prevent flight 
with aileron freeplay greater than the maximum limit.
    We agree to provide additional information. The repeat interval was 
selected after consideration of several factors related to known 
service experience, guidance from flutter analysis reference materials, 
and detailed flutter analysis. With respect to service experience, the 
absence of reports of buzzing or flutter events, known values of 
backlash freeplay, and the existing inspection interval were evaluated. 
Known backlash freeplay values were assessed against those recommended 
in flutter reference materials. A review of a recent flutter analysis 
conducted by Bombardier was also included in our consideration of an 
appropriate interval.
    Also, Bombardier, with the agreement of the airworthiness 
authorities (Transport Canada Civil Aviation (TCCA) and the FAA), has 
started monthly monitoring of the Model CRJ200 fleet since the 
inspection interval was lowered from 4,000 to 2,000 flight hours. After 
collecting sufficient data on the backlash freeplay that develops 
during the 2,000-flight-hour interval, further evaluation of the 
interval may be conducted.
    Therefore, we consider the proposed interval to be appropriate at 
this time. No change to the AD is necessary in this regard.

Request To Collect Aileron Freeplay Data

    The NTSB also requests that the FAA revise the AD to include a 
method for operators to record, retain, and report aileron freeplay 
check data. The NTSB is concerned that the FAA, TCCA, and Bombardier 
might fail to monitor the effects of the reduced interval appropriately 
by not collecting and analyzing aileron freeplay check data.
    We do not agree to revise the AD to add a requirement to collect 
and report data. While we have not mandated reporting of the aileron 
freeplay check measurements to the manufacturer, Task Card 000-27-900-
015 specifies recording and retaining this measurement. Bombardier is 
soliciting the measurement results from operators during the bi-monthly 
Technical Steering Committee meetings. As of January 2007, Bombardier 
has received feedback on over 70 airplanes and is confident that 
sufficient data will be available at the end of the 2-year term to 
provide validation of the check interval. TCCA requires Bombardier to 
provide the data results within 2 years after issuing Temporary 
Revision 1-2-33 to the MRM. Bombardier will tabulate the results based 
on the current methods and provide a matrix along with a recommendation 
to TCCA in mid-2008. There is no need to mandate a method for 
collecting the data, as there is a process in place. No change to the 
AD is necessary in this regard.

Request To Use Data in Monitoring Reclassification of Aileron Freeplay 
Check

    The NTSB suggests that aileron freeplay data provided by the 
operators also be used to assist the FAA, TCCA, and Bombardier in 
monitoring the reclassification of the bearing backlash test portion of 
the aileron freeplay check. The NTSB states that the NPRM proposes to 
reclassify the bearing backlash test portion of the aileron freeplay 
check from a certification maintenance requirement (CMR) task to an MRB 
task. The aileron freeplay backlash check would be replaced with an 
aileron PCU internal leakage test and would remain a CMR task.
    We agree that the aileron free play data could be useful. We will 
consider the NTSB's suggestion to use aileron freeplay data to monitor 
reclassification of the bearing backlash test once the service data are 
collected and we have reviewed the data. No change to the AD is 
necessary in this regard.

Clarification of Alternative Method of Compliance (AMOC) Paragraph

    We have revised this action 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 
comments received, and determined that air safety and the public 
interest require adopting the AD with the change described previously. 
We have determined that this change will neither increase the economic 
burden on any operator nor increase the scope of the AD.

Costs of Compliance

    This AD affects about 742 airplanes of U.S. registry. The required 
actions take about 1 work hour per airplane, at an average labor rate 
of $80 per work hour. Based on these figures, the estimated cost of the 
AD for U.S. operators is $59,360, or $80 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:
    (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:


[[Page 40226]]


    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):

2007-15-02 Bombardier, Inc. (Formerly Canadair): Amendment 39-15131. 
Docket No. FAA-2006-25779; Directorate Identifier 2006-NM-088-AD.

Effective Date

    (a) This AD becomes effective August 28, 2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Bombardier Model CL-600-2B19 
(Regional Jet Series 100 & 440) airplanes, certificated in any 
category.

Unsafe Condition

    (d) This AD results from a report that data collected from in-
service airplanes show that approximately 19 percent of aileron 
backlash checks conducted at 4,000-flight-hour intervals reveal that 
aileron backlash wear limits are being exceeded. We are issuing this 
AD to prevent exceeded backlashes in both aileron power control 
units (PCUs), which, if accompanied by the failure of the flutter 
damper, could result in aileron vibration/flutter and reduced 
controllability of the airplane.

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.

Revision of the Maintenance Requirements Manual (MRM)

    (f) Within 60 days after the effective date of this AD, revise 
the Canadair Regional Jet MRM CSP A-053 by doing the actions 
specified in paragraphs (f)(1) and (f)(2) of this AD. When the tasks 
specified in Canadair Regional Jet Temporary Revisions 2A-20, dated 
March 13, 2006; and 1-2-33, dated October 27, 2005; are included in 
the general revisions of the MRM, the general revisions may be 
inserted in the MRM, and these temporary revisions may be removed.
    (1) Revise the Certification Maintenance Requirements section of 
the Canadair Regional Jet MRM to include Tasks C27-10-105-06 and 
C27-10-105-05, as specified in Canadair Regional Jet Temporary 
Revision 2A-20, dated March 13, 2006, to Part 2, Appendix A--
Certification Maintenance Requirements, of the Canadair Regional Jet 
MRM CSP A-053.
    (2) Revise the Maintenance Review Board Report for Section 2--
Systems and Powerplant Program, of Part 1 of the Canadair Regional 
Jet MRM CSP A-053, to include the task interval for Task 27-11-00-
09, as specified in Canadair Regional Jet Temporary Revision 1-2-33, 
dated October 27, 2005. Incorporating Revision 10, dated May 27, 
2005, of the Canadair Regional Jet Maintenance Review Board Report 
for Section 2--Systems and Powerplant Program of the Canadair 
Regional Jet MRM CSP A-053 is one approved method for including the 
task interval specified in Canadair Regional Jet Temporary Revision 
1-2-33. After the task interval has been incorporated into the MRM, 
no alternative aileron backlash check interval in excess of 2,000 
flight hours may be approved, except as specified in paragraphs (g) 
and (h) of this AD.

Phase-In Schedule for Initial Inspection Specified in MRM Revisions

    (g) For airplanes with more than 1,000 flight hours but less 
than 3,000 flight hours since the last aileron backlash check 
specified in Task 27-11-00-09 was accomplished, as of the effective 
date of this AD: Within 1,000 flight hours after the effective date 
of this AD, do the next aileron backlash check in accordance with 
Task 27-11-00-09, as specified in Canadair Regional Jet Temporary 
Revision 1-2-33, dated October 27, 2005.
    (h) For airplanes with 3,000 flight hours or more since the last 
aileron backlash check specified in Task 27-11-00-09 was 
accomplished, as of the effective date of this AD: Within 4,000 
flight hours after the last aileron backlash check, do the next 
aileron backlash check in accordance with Task 27-11-00-09, as 
specified in Canadair Regional Jet Temporary Revision 1-2-33, dated 
October 27, 2005.

One Approved Method for Task C27-10-105-06

    (i) For airplanes without access to ground support equipment 
necessary to do the PCU internal leakage functional check, as 
specified in Task C27-10-105-06 specified in paragraph (f)(1) of 
this AD: Doing the aileron PCU internal leakage check in accordance 
with Task 27-11-00-220-803 of Chapter 27-11-00 of the Canadair 
Regional Jet Aircraft Maintenance Manual at intervals not to exceed 
4,000 flight hours is one approved method for accomplishing Task 
C27-10-105-06, and is acceptable for up to 12 months after the 
effective date of this AD. Thereafter, the check must be done in 
accordance with Task C27-10-105-06 as specified in paragraph (f)(1) 
of this AD at a repetitive interval not to exceed that specified in 
the task.

Alternative Methods of Compliance (AMOCs)

    (j)(1) The Manager, New York Aircraft Certification Office, FAA, 
has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
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.

Related Information

    (k) Canadian airworthiness directive CF-2006-04, dated March 22, 
2006, also addresses the subject of this AD.

Material Incorporated by Reference

    (l) You must use Canadair Regional Jet Temporary Revision 1-2-
33, dated October 27, 2005, to the Canadair Regional Jet Maintenance 
Review Manual CSP A-053; and Canadair Regional Jet Temporary 
Revision 2A-20, dated March 13, 2006, to the Canadair Regional Jet 
Maintenance Review Manual CSP A-053; to perform the actions that are 
required by this AD, unless the AD specifies otherwise. 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 Bombardier, Inc., Canadair, Aerospace Group, P.O. Box 
6087, Station Centre-ville, Montreal, Quebec H3C 3G9, Canada, for a 
copy of this service information. 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 July 11, 2007.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-13983 Filed 7-23-07; 8:45 am]
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