[Federal Register Volume 71, Number 31 (Wednesday, February 15, 2006)]
[Rules and Regulations]
[Pages 7843-7845]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 06-1295]



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  Federal Register / Vol. 71, No. 31 / Wednesday, February 15, 2006 / 
Rules and Regulations  

[[Page 7843]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-22632; Directorate Identifier 2005-NM-158-AD; 
Amendment 39-14486; AD 2006-04-05]
RIN 2120-AA64


Airworthiness Directives; Bombardier 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

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

ACTION: Final rule.

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

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Bombardier 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. This AD requires repetitive inspections for 
cracking or fracturing of the output links of the power control unit 
(PCU) for the ailerons, and related investigative and corrective 
actions if necessary. This AD results from reports of fractured output 
links of the aileron PCU. We are issuing this AD to prevent failure of 
an output link of the aileron PCU, which, if both links on one aileron 
fail, could result in reduced lateral control of the airplane.

DATES: This AD becomes effective March 22, 2006.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of March 22, 
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 Bombardier, Inc., Canadair, Aerospace Group, P.O. Box 6087, 
Station Centre-ville, 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 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 Bombardier 
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. That NPRM was published in the Federal Register on October 
7, 2005 (70 FR 58631). That NPRM proposed to require repetitive 
inspections for cracking or fracturing of the output links of the power 
control unit (PCU) for the ailerons, and related investigative and 
corrective actions if necessary.

Comments

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

Request for Method of Tracking Output Links of the Aileron PCUs

    The commenter, the National Transportation Safety Board (NTSB), 
supports the proposed AD, except that the NTSB suggests that we require 
the airplane manufacturer to develop and use a method for serializing 
and tracking individual output links of the aileron PCUs. The commenter 
observes that the output links do not have any identifying part number 
or serial number markings. The commenter states that this makes 
tracking an individual link difficult, especially since the proposed AD 
would require repetitive inspections.
    We do not agree with the commenter's request. The output links of 
the aileron PCU are neither principal structural elements nor life-
limited parts. Therefore, the Federal Aviation Regulations do not 
require each link to be marked with a serial number. The output links 
are marked with a part number and the manufacturing lot number of the 
top assembly (link and balls). These numbers are sufficient for 
tracking the output links in order to address potential issues with 
quality assurance.
    Also, we note that the repetitive inspection interval of 1,000 
flight hours is intended to be flight hours on the airplane, not on an 
individual output link. If a link is replaced with a new link between 
inspection cycles, the new link will be inspected at the next required 
inspection cycle. Thus, each link will always be inspected as required 
by this AD after no more than 1,000 flight hours. We find that tracking 
the output links by serial number would not add any additional level of 
safety. We have not changed the final rule in this regard.

Request To Explain Inspection Interval

    The commenter also requests that we explain the rationale for 
establishing a repetitive inspection interval of 1,000 flight hours. 
The commenter notes that neither the proposed AD nor the referenced 
service bulletin (Bombardier Alert Service Bulletin A670BA-27-023, 
including Appendix A, Revision A, dated May 18, 2005) explains the 
rationale for this interval. The commenter is concerned that the 
interval may need to be reduced.
    We agree to provide the clarification that the commenter requests, 
although we note that such a rationale is not normally stated in an AD 
unless we are disagreeing with the compliance time recommended by the 
cognizant airworthiness authority. (In this case, the proposed 
repetitive interval of 1,000 flight hours is consistent with the 
repetitive interval that Transport Canada Civil Aviation (TCCA), the

[[Page 7844]]

airworthiness authority for Canada, recommends in its parallel 
airworthiness directive.)
    In developing an appropriate compliance time for this AD, we 
considered the manufacturer's recommendation and the degree of urgency 
associated with the subject unsafe condition, as well as the following:
     Data from failures of the output link in service on 
Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. 
There have been no link failures reported on Bombardier Model CL-600-
2C10 (Regional Jet Series 700, 701, & 702), CL-600-2D15 (Regional Jet 
Series 705), or CL-600-2D24 (Regional Jet Series 900) airplanes, 
although the design of the aileron control system on these airplanes is 
the same as that on Model CL-600-2B19 (Regional Jet Series 100 & 440) 
airplanes. A total of seven fractured output links have been reported 
in more than 12,000,000 flight hours accumulated on Bombardier Model 
CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. Analysis of the 
data from the failed links reveals that the in-service failure rate is 
slightly in excess of the certification requirements. However, of the 
fractured links, the one with the lowest amount of time had accumulated 
approximately 6,000 flight hours.
     Laboratory analysis of failed links. Two of the fractured 
links were submitted to a laboratory for examination to determine the 
failure mode of the fracture, the metallurgical characteristics of the 
links and other components of the assembly, and the probable cause of 
the failure. The laboratory could not determine the cause of the 
failure or the crack growth rate. Based on this analysis, it was 
determined that an interim action--repetitive inspections for cracking 
or fracturing of the aileron PCU output links, and related 
investigative and corrective actions--was necessary.
     Maintenance and operational checks that are currently 
required to identify any failure in the aileron control system:
    [cir] An operational test for PCU disconnect every A-check 
(approximately every 500 flight hours).
    [cir] An aileron backlash check every 4,000 flight hours (currently 
in the process of being reduced to every 2,000 flight hours).
    [cir] A test for PCU stiffness, and a detailed inspection of the 
PCU and flutter damper attachments for condition, safety of 
installation, and signs of leakage, and a detailed inspection of the 
PCU for signs of leakage, every C-check (approximately every 5,000 
flight hours).
    In light of all of these factors, we agree with TCCA that a 1,000-
flight-hour repetitive interval represents an appropriate interval of 
time for affected airplanes to continue to operate without compromising 
safety. We have not changed the final rule in this regard.

Conclusion

    We have carefully reviewed the available data, including the 
comment received, and determined that air safety and the public 
interest require adopting the AD as proposed.

Interim Action

    We consider this AD interim action. The inspection reports that are 
required by this AD will enable the manufacturer to obtain better 
insight into the nature, cause, and extent of the cracking, and 
eventually to develop final action to address the unsafe condition. 
Once final action has been identified, we may consider further 
rulemaking.

Costs of Compliance

    This AD affects about 205 airplanes of U.S. registry. The required 
inspection will take about 1 work hour per airplane, per inspection 
cycle, at an average labor rate of $65 per work hour. Based on these 
figures, the estimated cost of this inspection for U.S. operators is 
$13,325, or $65 per airplane, per inspection cycle.

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:

    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):

2006-04-05 Bombardier, Inc. (Formerly Canadair): Amendment 39-14486. 
Docket No. FAA-2005-22632; Directorate Identifier 2005-NM-158-AD.

Effective Date

    (a) This AD becomes effective March 22, 2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to the Bombardier airplanes identified in 
Table 1 of this AD, certificated in any category.

                         Table 1.--Applicability
------------------------------------------------------------------------
        Bombardier airplane models                 Serial  numbers
------------------------------------------------------------------------
CL-600-2C10 (Regional Jet Series 700, 701,  10003 and subsequent.
 & 702) airplanes.

[[Page 7845]]

 
CL-600-2D15 (Regional Jet Series 705)       15001 and subsequent.
 airplanes.
CL-600-2D24 (Regional Jet Series 900)       15001 and subsequent.
 airplanes.
------------------------------------------------------------------------

Unsafe Condition

    (d) This AD results from reports of fractured output links of 
the power control unit (PCU) for the ailerons. We are issuing this 
AD to prevent failure of an output link of the aileron PCU, which, 
if both links on one aileron fail, could result in reduced lateral 
control 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.

Repetitive Inspections, Related Investigative Actions, and Corrective 
Actions

    (f) Prior to the accumulation of 2,000 total flight hours, or 
within 550 flight hours after the effective date of this AD, 
whichever is later: Do a detailed inspection for cracking or 
fracturing of the output links of the aileron PCU and do all related 
investigative and corrective actions, as applicable, in accordance 
with the Accomplishment Instructions of Bombardier Alert Service 
Bulletin A670BA-27-023, including Appendix A, Revision A, dated May 
18, 2005, except as provided by paragraph (g) of this AD. 
Thereafter, repeat the inspection and applicable related 
investigative and corrective actions at intervals not to exceed 
1,000 flight hours. Any applicable related investigative and 
corrective actions must be done before further flight after the 
inspection.

    Note 1: For the purposes of this AD, a detailed inspection is: 
``An intensive examination of a specific item, installation, or 
assembly to detect damage, failure, or irregularity. Available 
lighting is normally supplemented with a direct source of good 
lighting at an intensity deemed appropriate. Inspection aids such as 
mirror, magnifying lenses, etc., may be necessary. Surface cleaning 
and elaborate procedures may be required.''

Exception to Corrective Action Instructions

    (g) If any cracking or other damage is found on an aileron lug 
or flange bushing during any inspection required by this AD, and the 
service bulletin recommends contacting Bombardier for appropriate 
action: Before further flight, disposition and replace the cracked 
or damaged aileron lug or flange bushing with a new part, in 
accordance with a method approved by the Manager, New York Aircraft 
Certification Office (ACO), FAA; or Transport Canada Civil Aviation 
(TCCA) (or its delegated agent).

Reporting

    (h) Submit a report of the findings (both positive and negative) 
of the inspections required by paragraph (f) of this AD to 
Bombardier Aerospace; Attention: Christian Holzl, dept. 508; 
Location S666 1422 024; 13100 Highway 50; Mirabel, Quebec, J7M 3C6, 
Canada; fax (450) 476-7321. Submit the report at the applicable time 
specified in paragraph (h)(1) or (h)(2) of this AD. The report must 
include the airplane serial number, the total accumulated flight 
cycles and flight hours on the airplane, the date of the inspection, 
the total accumulated flight cycles and flight hours at the last 
``C'' check, the serial number of each PCU, and the results of all 
inspections, tests, and measurements done in accordance with 
paragraph (f) of this AD. Submitting Appendix A of Bombardier Alert 
Service Bulletin A670BA-27-023, including Appendix A, Revision A, 
dated May 18, 2005, is an acceptable means of complying with this 
requirement. Under the provisions of the Paperwork Reduction Act of 
1980 (44 U.S.C. 3501 et seq.), the Office of Management and Budget 
(OMB) has approved the information collection requirements contained 
in this AD and has assigned OMB Control Number 2120-0056.
    (1) If the inspection was done after the effective date of this 
AD: Submit the report within 30 days after the inspection.
    (2) If the inspection was done prior to the effective date of 
this AD: Submit the report within 30 days after the effective date 
of this AD.

Actions Accomplished Previously

    (i) Inspections and corrective actions done, and reports 
submitted, before the effective date of this AD in accordance with 
Bombardier Alert Service Bulletin A670BA-27-023, including Appendix 
A, dated May 3, 2005, are acceptable for compliance with the 
corresponding requirements of paragraphs (f) and (h) of this AD.

Alternative Methods of Compliance (AMOCs)

    (j)(1) The Manager, New York ACO, 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 FAA Flight Standards 
Certificate Holding District Office.

Related Information

    (k) Canadian airworthiness directive CF-2005-23, dated June 29, 
2005, also addresses the subject of this AD.

Material Incorporated by Reference

    (l) You must use Bombardier Alert Service Bulletin A670BA-27-
023, including Appendix A, Revision A, dated May 18, 2005, 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 this document 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 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.

    Issued in Renton, Washington, on February 1, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 06-1295 Filed 2-14-06; 8:45 am]
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