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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2015-0822; Directorate Identifier 2014-NM-210-AD]
          - RIN 2120-AA64

# AGENCY:

Federal Aviation Administration (FAA), DOT.

# ACTION:

Notice of proposed rulemaking (NPRM).

# SUMMARY:

We propose to adopt a new airworthiness directive (AD) for certain Bombardier, Inc. Model CL-600-2C10 (Regional Jet Series 700, 701, & 702) airplanes, Model CL-600-2D15 (Regional Jet Series 705) airplanes, Model CL-600-2D24 (Regional Jet Series 900) airplanes, and Model CL-600-2E25 (Regional Jet Series 1000) airplanes. This proposed AD was prompted by results of a design review indicating that the burst pressure of the flexible hose, used to vent oxygen from the high-pressure relief valve of the oxygen cylinder overboard, was lower than the opening pressure of the high-pressure relief valve, which could cause the flexible hose to burst before it can vent the excess oxygen overboard. This proposed AD would require replacing the oxygen hose assembly with a new, improved assembly. We are proposing this AD to prevent the accumulation of oxygen in an enclosed space, which could result in an uncontrolled oxygen-fed fire if an ignition source is nearby.

# DATES:

We must receive comments on this proposed AD by May 28, 2015.

# ADDRESSES:

You may send comments by any of the following methods:
      -  Federal eRulemaking Portal:                          Go to                          http://www.regulations.gov . Follow the instructions for submitting comments.                    
      -  Fax:                          (202) 493-2251.                    
      -  Mail:                          U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590.                    
      -  Hand Delivery:                          U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.                    

                        For service information identified in this proposed 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*. You may view this referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425-227-1221.                    

## Examining the AD Docket

                    You may examine the AD docket on the Internet at                     *http://www.regulations.gov*                     by searching for and locating Docket No. FAA-2015-0822; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday,                           ( print page 19575)                        except Federal holidays. The AD docket contains this proposed AD, 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.                

# 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, NY 11590; telephone (516) 228-7318; fax (516) 794-5531.

# SUPPLEMENTARY INFORMATION:

## Comments Invited

                    We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the                     **ADDRESSES**                     section. Include “Docket No. FAA-2015-0822; Directorate Identifier 2014-NM-210-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD based on those comments.                

                    We will post all comments we receive, without change, to                     *http://www.regulations.gov,*                     including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.                

## Discussion

Transport Canada Civil Aviation (TCCA), which is the airworthiness authority for Canada, has issued Canadian Airworthiness Directive CF-2014-37, dated October 17, 2014 (referred to after this as the Mandatory Continuing Airworthiness Information, or “the MCAI”), to correct an unsafe condition for certain Bombardier, Inc. Model CL-600-2C10 (Regional Jet Series 700, 701, & 702) airplanes, Model CL-600-2D15 (Regional Jet Series 705) airplanes, Model CL-600-2D24 (Regional Jet Series 900) airplanes, and Model CL-600-2E25 (Regional Jet Series 1000) airplanes. The MCAI states:

Design review found that the burst pressure of the flexible hose, used to vent oxygen from the high-pressure relief valve of the oxygen cylinder overboard, is lower than the opening pressure of the high-pressure relief valve. This could cause the flexible hose to burst before it is able to vent the excess oxygen overboard. If an ignition source is present, the accumulation of oxygen in an enclosed space may result in an uncontrolled oxygen-fed fire.

This [Canadian] AD mandates the replacement of the oxygen hose assembly with a new design oxygen hose assembly.

                    You may examine the MCAI in the AD docket on the Internet at                     *http://www.regulations.gov*                     by searching for and locating Docket No. FAA-2015-0822.                

## Related Service Information Under 1 CFR Part 51

                    Bombardier has issued Service Bulletin 670BA-35-013, Revision A, dated September 23, 2013, including Appendix A, dated May 21, 2013. The service information describes procedures for replacing the oxygen hose assembly with a new, improved assembly. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI. This service information is reasonably available; see                     **ADDRESSES**                     for ways to access this service information.                

## FAA's Determination and Requirements of This Proposed AD

This product has been approved by the aviation authority of another country, and is approved for operation in the United States. Pursuant to our bilateral agreement with the State of Design Authority, we have been notified of the unsafe condition described in the MCAI and service information referenced above. We are proposing this AD because we evaluated all pertinent information and determined an unsafe condition exists and is likely to exist or develop on other products of the same type design.

## Costs of Compliance

We estimate that this proposed AD affects 400 airplanes of U.S. registry.

We also estimate that it would take about 10 work-hours per product to comply with the basic requirements of this proposed AD. Required parts would cost about $0 per product. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of this proposed AD on U.S. operators to be $340,000, or $850 per airplane.

According to the manufacturer, some of the costs of this proposed AD may be covered under warranty, thereby reducing the cost impact on affected individuals. We do not control warranty coverage for affected individuals. As a result, we have included all costs in our cost estimate

## 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 proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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 proposed regulation:

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.

# List of Subjects in 14 CFR Part 39

      - Air transportation
      - Aircraft
      - Aviation safety
      - Incorporation by reference
      - Safety

## The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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 airworthiness directive (AD): 
      ( print page 19576)    
**Bombardier, Inc.:**                         Docket No. FAA-2015-0822; Directorate Identifier 2014-NM-210-AD.                    

## (a) Comments Due Date

We must receive comments by May 28, 2015.

## (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 10002 through 10336 inclusive.

(2) Bombardier, Inc. Model CL-600-2D15 (Regional Jet Series 705), and Model CL-600-2D24 (Regional Jet Series 900) airplanes, serial numbers 15001 through 15297 inclusive.

(3) Bombardier, Inc. Model CL-600-2E25 (Regional Jet Series 1000) airplanes, serial numbers 19001 through 19038 inclusive.

## (d) Subject

Air Transport Association (ATA) of America Code 35, Oxygen.

## (e) Reason

This AD was prompted by results of a design review indicating that the burst pressure of the flexible hose, used to vent oxygen from the high-pressure relief valve of the oxygen cylinder overboard, was lower than the opening pressure of the high-pressure relief valve, which could cause the flexible hose to burst before it can vent the excess oxygen overboard. We are issuing this AD to prevent the accumulation of oxygen in an enclosed space, which could result in an uncontrolled oxygen-fed fire if an ignition source is nearby.

## (f) Compliance

Comply with this AD within the compliance times specified, unless already done.

## (g) Replacement

                        Before the accumulation of 5,800 total flight hours, or within 44 months after the effective date of this AD, whichever occurs first, replace all oxygen hose assemblies having part number (P/N) S6946-01 with new, improved assemblies having P/N BA670-44025-001, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 670BA-35-013, Revision A, dated September 23, 2013, including Appendix A, dated May 21, 2013. For airplanes on which Supplemental Type Certificate ST01648NY (                        *http://rgl.faa.gov/​Regulatory_​and_​Guidance_​Library/​rgstc.nsf/​0/​ebd1cec7b301293e86257cb30045557a/​$FILE/​ST01648NY.pdf*) is installed, only PART B of the Accomplishment Instructions of Bombardier Service Bulletin 670BA-35-013, Revision A, dated September 23, 2013, is required.                    

## (h) Credit for Previous Actions

This paragraph provides credit for the replacement specified in paragraph (g) of this AD, if that action was performed before the effective date of this AD using Bombardier Service Bulletin 670BA-35-013, dated May 21, 2013, which is not incorporated by reference in this AD.

## (i) Parts Installation Prohibition

As of the effective date of this AD, no person may install an oxygen hose assembly, P/N S6946-01, on any airplane.

## (j) 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. Send information to ATTN: Program Manager, Continuing Operational Safety, FAA, New York ACO, 1600 Stewart Avenue, Suite 410, Westbury, NY 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)                         *Contacting the Manufacturer:*                         For any requirement in this AD to obtain corrective actions from a manufacturer, the action must be accomplished using a method approved by the Manager, New York ACO, ANE-170, FAA; or Transport Canada Civil Aviation (TCCA); or Bombardier, Inc.'s TCCA Design Approval Organization (DAO). If approved by the DAO, the approval must include the DAO-authorized signature.                    

## (k) Related Information

                        (1) Refer to Mandatory Continuing Airworthiness Information (MCAI) Canadian Airworthiness Directive CF-2014-37, dated October 17, 2014, for related information. This MCAI may be found in the AD docket on the Internet at                         *http://www.regulations.gov*                         by searching for and locating Docket No. FAA-2015-0822.                    

                        (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*. You may view this service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425-227-1221.                    

Issued in Renton, Washington, on March 27, 2015.

Michael Kaszycki,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 2015-08329 Filed 4-10-15; 8:45 am]

 BILLING CODE 4910-13-P