
[Federal Register Volume 76, Number 25 (Monday, February 7, 2011)]
[Rules and Regulations]
[Pages 6539-6541]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-2443]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-1109; Directorate Identifier 2010-NM-155-AD; 
Amendment 39-16597; AD 2011-03-13]
RIN 2120-AA64


Airworthiness Directives; Bombardier, Inc. Model CL-600-2C10 
(Regional Jet Series 700, 701, & 702) Airplanes, Model CL-600-2D15 
(Regional Jet Series 705) Airplanes, and Model CL-600-2D24 (Regional 
Jet Series 900) 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 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:

    Rudder Travel Limiter (RTL) return spring, part number (P/N) 
E0650-069-2750S, failed prior to completion of the required 
endurance test. In addition, the replacement RTL return spring, P/N 
670-93465-1 * * * was found to be susceptible to chafing on the 
primary actuator, which could also result in eventual dormant spring 
failure. There are two return springs in the RTL and if both springs 
failed, a subsequent mechanical disconnect of the RTL components 
would result in an unannunciated failure of the RTL. This, in turn, 
would permit an increase of rudder authority beyond normal 
structural limits and, in the event of a strong rudder input, 
controllability of the aeroplane could be affected.
* * * * *
    We are issuing this AD to require actions to correct the unsafe 
condition on these products.

DATES: This AD becomes effective March 14, 2011.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of March 14, 
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: Cesar Gomez, Aerospace Engineer, 
Airframe and Mechanical Systems Branch, ANE-171, FAA, New York Aircraft 
Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New 
York 11590; telephone (516) 228-7318; 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 November 10, 2010 
(75 FR 69030). That NPRM proposed to correct an unsafe condition for 
the specified products. The MCAI states:

    Rudder Travel Limiter (RTL) return spring, part number (P/N) 
E0650-069-2750S, failed prior to completion of the required 
endurance test. In addition, the replacement RTL return spring, P/N 
670-93465-1 (see Note) was found to be susceptible to chafing on the 
primary actuator, which could also result in eventual dormant spring 
failure. There are two return springs in the RTL and

[[Page 6540]]

if both springs failed, a subsequent mechanical disconnect of the 
RTL components would result in an unannunciated failure of the RTL. 
This, in turn, would permit an increase of rudder authority beyond 
normal structural limits and, in the event of a strong rudder input, 
controllability of the aeroplane could be affected.
    Note: RTL return springs, P/N 670-93465-1, were installed in 
production aeroplanes serial number 10266 (CL-600-2C10) and 15182 
(CL-600-2D24) respectively and were introduced in-service by 
[Bombardier] Service Bulletin (SB) 670BA-27-047. SB 670BA-27-047 has 
since been superseded by [Bombardier] SB 670BA-27-055.
    This directive mandates repetitive [detailed] inspection of the 
RTL [for broken] return springs and [damage through the casing, or 
chafing of the casing of the] primary actuator, with replacement of 
parts as necessary.

    Corrective actions include replacing any broken return springs with 
new return springs, repairing any chafing of the primary actuator on 
its casing, and replacing any primary actuator that has damage through 
its casing with a new actuator. 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 477 products of U.S. registry. 
We also estimate that it will take 2 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 $81,090, or $170 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

    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:

2011-03-13 Bombardier, Inc.: Amendment 39-16597. Docket No. FAA-
2010-1109; Directorate Identifier 2010-NM-155-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective March 
14, 2011.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Bombardier, Inc. Model CL-600-2C10 
(Regional Jet Series 700, 701, & 702) airplanes, serial numbers 
10003 and subsequent; and Model CL-600-2D15 (Regional Jet Series 
705) and Model CL-600-2D24 (Regional Jet Series 900) airplanes, 
serial numbers 15001 and subsequent; certificated in any category.

Subject

    (d) Air Transport Association (ATA) of America Code 27: Flight 
controls.

Reason

    (e) The mandatory continuing airworthiness information (MCAI) 
states:
    Rudder Travel Limiter (RTL) return spring, part number (P/N) 
E0650-069-2750S, failed prior to completion of the required 
endurance test. In addition, the replacement RTL return spring, P/N 
670-93465-1 * * * was found to be susceptible to chafing on the 
primary actuator, which could also result in eventual dormant spring 
failure. There are two return springs in the RTL and if both springs 
failed, a subsequent mechanical disconnect of the RTL components 
would result in an unannunciated failure of the RTL. This, in turn, 
would permit an increase of rudder authority beyond normal 
structural limits and, in the event of a strong rudder input, 
controllability of the aeroplane could be affected.
* * * * *

Compliance

    (f) You are responsible for having the actions required by this 
AD performed within

[[Page 6541]]

the compliance times specified, unless the actions have already been 
done.

Initial Inspections and Replacement/Repair

    (g) For airplanes that have accumulated 4,000 or less total 
flight hours as of the effective date of this AD: Before the 
accumulation of 6,000 total flight hours, do a detailed inspection 
of the RTL for broken return springs and damage through the casing, 
or chafing of the casing of the primary actuator, in accordance with 
the Accomplishment Instructions of Bombardier Service Bulletin 
670BA-27-055, Revision A, dated August 6, 2010. Before further 
flight, replace any broken return springs with new springs, and 
repair or replace with a new actuator any chafed or damaged primary 
actuator, as applicable, in accordance with the Accomplishment 
Instructions of Bombardier Service Bulletin 670BA-27-055, Revision 
A, dated August 6, 2010. Repeat the inspection thereafter at 
intervals not to exceed 6,000 flight hours.
    (h) For airplanes that have accumulated more than 4,000 total 
flight hours as of the effective date of this AD: Within 2,000 
flight hours after the effective date of this AD, do a detailed 
inspection of the RTL for broken return springs and damage through 
the casing, or chafing of the casing of the primary actuator, in 
accordance with the Accomplishment Instructions of Bombardier 
Service Bulletin 670BA-27-055, Revision A, dated August 6, 2010. 
Before further flight, replace any broken return springs with new 
springs, and repair or replace any chafed or damaged primary 
actuator with a new actuator, as applicable, in accordance with the 
Accomplishment Instructions of Bombardier Service Bulletin 670BA-27-
055, Revision A, dated August 6, 2010. Repeat the inspection 
thereafter at intervals not to exceed 6,000 flight hours.

Credit for Actions Accomplished in Accordance With Previous Service 
Information

    (i) Actions accomplished before the effective date of this AD in 
accordance with Bombardier Service Bulletin 670BA-27-055, dated May 
11, 2010, are considered acceptable for compliance with the 
corresponding actions specified in this AD.

FAA AD Differences

    Note 1: This AD differs from the MCAI and/or service information 
as follows: No differences.

Other FAA AD Provisions

    (j) 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, has the 
authority to approve AMOCs for this AD, if requested using the 
procedures found in 14 CFR 39.19. Send information 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

    (k) Refer to MCAI Canadian Airworthiness Directive CF-2010-18, 
dated June 16, 2010; and Bombardier Service Bulletin 670BA-27-055, 
Revision A, dated August 6, 2010; for related information.

Material Incorporated by Reference

    (l) You must use Bombardier Service Bulletin 670BA-27-055, 
Revision A, dated August 6, 2010, 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; e-mail 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 January 25, 2011.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-2443 Filed 2-4-11; 8:45 am]
BILLING CODE 4910-13-P


