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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2011-1223; Directorate Identifier 2011-NM-173-AD; Amendment 39-17027; AD 2012-08-10]
          - RIN 2120-AA64

# AGENCY:

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

# ACTION:

Final rule.

# SUMMARY:

We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc. Model CL-600-2B16 (CL-604 Variant) 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 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                               ( print page 24348)                            of certain publications 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 69155). 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. It was found that the low threshold setting of the circuit protection on the ADG generator control unit (GCU) can prevent the supply of power from the ADG to the essential buses. In the event of an emergency, loss of power to the essential buses 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 considered the comment received.

## Request To Remove Unaffected Airplane Models

Bombardier requested that we revise the proposed applicability to remove Model CL-601-3A and CL-601-3R airplanes.

We agree. We have removed these models from the Summary and paragraph (c) of this AD, since only the Model CL-604 variant is affected.

## Explanation of Change to Costs of Compliance Section

The Costs of Compliance section has been updated to show a more accurate cost to operators. The work-hours quoted in Bombardier Service Bulletins 604-24-023 and 605-24-003, dated April 27, 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 replacing the printed wiring assemblies in 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, for a total estimate of 6 work-hours.

## Conclusion

We reviewed the available data, including the comment 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

We estimate that this AD will affect 70 products of U.S. registry. We also estimate that it will take about 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 will cost about $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 to the U.S. operators to be $35,700, 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.

## 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 69155, 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

1. The authority citation for part 39 continues to read as follows: 

Authority:49 U.S.C. 106(g), 40113, 44701.

§ 39.13 

2. The FAA amends § 39.13 by adding the following new AD: 

**2012-08-10 Bombardier, Inc.:**                             Amendment 39-17027. Docket No. FAA-2011-1223; Directorate Identifier 2011-NM-173-AD.                                  ( print page 24349)    

## (a) Effective Date

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

## (b) Affected ADs

None.

## (c) Applicability

This AD applies to Bombardier, Inc. Model CL-600-2B16 (CL-604 Variant) airplanes, certificated in any category, serial numbers 5408 through 5665 inclusive, and 5701 through 5856 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 36 months after the effective date of this AD, 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 605-24-003, dated April 25, 2011 (for airplane serial numbers 5701 through 5856); or Bombardier Service Bulletin 604-24-023, dated April 25, 2011 (for airplane serial numbers 5408 through 5665).

# Note 1 to paragraph (g) of this AD:

 Bombardier Service Bulletins 605-24-003 and 604-24-023, both dated April 25, 2011, refer 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 using a new part number.

## (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 10, 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-2011-25, dated July 25, 2011; Bombardier Service Bulletin 605-24-003, dated April 25, 2011; and Bombardier Service Bulletin 604-24-023, dated April 25, 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 605-24-003, dated April 25, 2011.

(ii) Bombardier Service Bulletin 604-24-023, dated April 25, 2011.

                            (2) For service information identified in this AD, contact Bombardier, Inc., 400 Côte-Vertu Road West, Dorval, Québec 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 10, 2012.

John P. Piccola,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 2012-9395 Filed 4-23-12; 8:45 am]

BILLING CODE 4910-13-P