
[Federal Register Volume 77, Number 79 (Tuesday, April 24, 2012)]
[Rules and Regulations]
[Pages 24364-24366]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-9194]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-1228; Directorate Identifier 2011-NM-176-AD; 
Amendment 39-17022; AD 2012-08-05]
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 certain 
Bombardier, Inc. Model CL-600-2C10 (Regional Jet Series 700, 701, & 
702), CL-600-2D15 (Regional Jet Series 705), CL-600-2D24 (Regional Jet 
Series 900), and CL-600-2E25 (Regional Jet Series 1000) airplanes. This 
AD was prompted by reports of the air driven generator (ADG) failing to 
power essential buses during functional tests, due to the low threshold 
setting of the circuit protection on the ADG's generator control unit 
(GCU) preventing the ADG from supplying power to the essential buses. 
This AD requires installing a new

[[Page 24365]]

or serviceable ADG GCU. We are issuing this AD to prevent loss of power 
from the ADG to the essential buses which, in the event of an 
emergency, could prevent continued safe flight.

DATES: This AD becomes effective May 29, 2012.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of May 29, 
2012.

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: Assata Dessaline, Aerospace Engineer, 
Avionics and Flight Test Branch, ANE-172, FAA, New York Aircraft 
Certification Office (ACO), 1600 Stewart Avenue, Suite 410, Westbury, 
New York 11590; telephone (516) 228-7301; 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 8, 2011 (76 
FR 69166). That NPRM proposed to correct an unsafe condition for the 
specified products. The MCAI states:

    There have been several occurrences of the air driven generator 
(ADG) failure to power essential buses during functional tests of 
the ADG on aeroplane models CL-600-2B16 and CL-600-2B19. The 
aeroplane models CL-600-2C10, CL-600-2D15, CL-600-2D24, and CL-600-
2E25 use the same ADG generator control unit (GCU) as models CL-600-
2B16 and CL-600-2B19. However the aeroplane models CL-600-2C10, CL-
600-2D15, CL-600-2D24, and CL-600-2E25 are installed with a 
different hydraulic pump and do not experience the same failure due 
to the low threshold setting of the circuit protection.
    However, it was found that the same ADG GCU transformer primary 
winding can break due to thermal fatigue. Broken transformer primary 
winding can prevent the supply of power from the ADG to the 
essential buses. In the event of an emergency, failure for the 
essential buses to remain powered can prevent continued safe flight.
    This [TCCA] directive mandates the replacement of the ADG GCU.

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 have considered the comments received.

Request To Shorten the Compliance Time

    The Air Line Pilots Association, International (ALPA) requested the 
compliance time of ``10,000 flight hours or 60 months after the 
effective date of the AD'' be reduced, because ALPA believes that the 
compliance time is too long to comply with the proposed AD (76 FR 
69166, November 8, 2011) based on the importance of replacement.
    We do not agree to shorten the compliance time. In developing the 
compliance time, we determined that the compliance time of 10,000 
flight hours or 60 months after the effective date of the AD (whichever 
is first), is appropriate when considering the safety implications, the 
average utilization rate of the affected fleet, the practical aspects 
of an orderly inspection of the fleet during regular maintenance 
periods, and the availability of required replacement parts. In 
addition, our compliance time corresponds with the 10,000-flight-hour 
or 60-month compliance time of the parallel AD issued by Transport 
Canada Civil Aviation (TCCA). We have not changed the AD in this 
regard.

Request To Reference Hamilton Sundstrand's Part Number

    Comair, Inc. requested that we revise paragraphs (g) and (h) of the 
NPRM (76 FR 69166, November 8, 2011) to reference Hamilton Sundstrand's 
part number, in addition to the Bombardier part numbers for the ADG 
GCU, because by doing so, Comair believes the proposed AD will make 
certain all suspect ADG GCUs are removed and replaced and will be 
congruent with the manufacturer's manual.
    We agree with the request to reference the Hamilton Sundstrand part 
number for the ADG GCU unit that is affected and not higher assembly 
part numbers. Bombardier Service Bulletin 670BA-24-031, dated May 30, 
2011, refers to Hamilton Sundstrand Service Bulletin ERPS10G-24-1, 
dated February 9, 2011, as an additional source of guidance for 
modifying and testing the ADG GCU with new printed wiring assemblies 
and re-identifying the GCU with a new part number. We have updated 
paragraphs (g) and (h) of this AD to include the Hamilton Sundstrand 
part number.

Explanation of Change to Costs of Compliance Section

    The Costs of Compliance section in this AD has been updated to show 
a more accurate cost to operators. The work-hours quoted in Bombardier 
Service Bulletin 670BA-24-031, dated May 30, 2011, include only the 
labor time required for replacement, while Hamilton Sundstrand Service 
Bulletin ERPS10G-24-1, dated February 9, 2011, estimates 4 work-hours 
for replacement of the printed wiring assemblies from the GCU and 
functional testing of the ADG. Because it may be necessary to do a non-
destructive test (NDT) inspection on some airplanes, we have added an 
additional work-hour, resulting in a total labor time estimate of 6 
work-hours in the Costs of Compliance section of this AD.

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 changes described previously. We determined that these 
changes will not increase the economic burden on any operator or 
increase the scope of the AD.

Costs of Compliance

    Based on the service information, we estimate that this AD affects 
402 products of U.S. registry. We also estimate that it takes 6 work-
hours per product to comply with the basic requirements of this AD. The 
average labor rate is $85 per work-hour. Required parts cost $0 per 
product. Where the service information lists required parts costs that 
are covered under warranty, we have assumed that there will be no 
charge for these parts. As we do not control warranty coverage for 
affected parties, some parties may incur costs higher than estimated 
here. Based on these figures, we estimate the cost of this AD on U.S. 
operators to be $205,020, or $510 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.

[[Page 24366]]

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 that 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);
    3. Will not affect intrastate aviation in Alaska; and
    4. 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 69166, November 8, 
2011), 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:

2012-08-05 Bombardier, Inc.: Amendment 39-17022. Docket No. FAA-
2011-1228; Directorate Identifier 2011-NM-176-AD.

(a) Effective Date

    This airworthiness directive (AD) becomes effective May 29, 
2012.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to the airplanes, certificated in any category, 
identified in paragraphs (c)(1), (c)(2), and (c)(3) of this AD.
    (1) Bombardier, Inc. Model CL-600-2C10 (Regional Jet Series 700, 
701, & 702) airplanes, serial numbers 10003 through 10319 inclusive.
    (2) Bombardier, Inc. Model CL-600-2D15 (Regional Jet Series 705) 
and CL-600-2D24 (Regional Jet Series 900) airplanes, serial numbers 
15001 through 15260 inclusive.
    (3) Bombardier, Inc. Model CL-600-2E25 (Regional Jet Series 
1000) airplanes, serial numbers 19001 through 19012 inclusive.

(d) Subject

    Air Transport Association (ATA) of America Code 24: Electrical 
Power.

(e) Reason

    This AD was prompted by reports of the air driven generator 
(ADG) failing to power essential buses during functional tests, due 
to the low threshold setting of the circuit protection on the ADG's 
generator control unit (GCU) preventing the ADG from supplying power 
to the essential buses. We are issuing this AD to prevent loss of 
power from the ADG to the essential buses which, in the event of an 
emergency, could prevent continued safe flight.

(f) Compliance

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

(g) Actions

    Within 10,000 flight hours or 60 months after the effective date 
of this AD, whichever occurs first, remove the ADG GCU, Bombardier 
part number (P/N) 604-90800-7 (Hamilton Sundstrand P/N 761341A) and 
install a new or serviceable ADG GCU, Bombardier P/N 604-90800-27 
(Hamilton Sundstrand P/N 761341B), in accordance with the 
Accomplishment Instructions of Bombardier Service Bulletin 670BA-24-
031, dated May 30, 2011.

(h) Parts Installation

    As of the effective date of this AD, no person may install an 
ADG GCU, Bombardier P/N 604-90800-7 (Hamilton Sundstrand P/N 
761341A) on any airplane.

(i) Other FAA AD Provisions

    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. 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.

(j) Related Information

    Refer to MCAI Canadian Airworthiness Directive CF-2011-27, dated 
July 25, 2011; and Bombardier Service Bulletin 670BA-24-031, dated 
May 30, 2011; for related information.

(k) Material Incorporated by Reference

    (1) You must use the following service information to do the 
actions required by this AD, unless the AD specifies otherwise. The 
Director of the Federal Register approved the incorporation by 
reference (IBR) of the following service information under 5 U.S.C. 
552(a) and 1 CFR part 51:
    (i) Bombardier Service Bulletin 670BA-24-031, dated May 30, 
2011.
    (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 an NARA facility, 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 April 6, 2012.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-9194 Filed 4-23-12; 8:45 am]
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