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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2011-1088; Directorate Identifier 2011-NM-099-AD; Amendment 39-16985; AD 2012-06-04]
          - RIN 2120-AA64

# AGENCY:

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

# ACTION:

Final rule.

      ( print page 16429)    

# SUMMARY:

We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc. Model DHC-8-400 series airplanes. This AD was prompted by reports of difficulties in opening the airstair door. This AD requires inspecting the structure and gearbox drain paths for blockages by sealant, and removing any blockages. We are issuing this AD to detect and correct drain paths blocked by sealant, resulting in an airstair door that is unable to be opened, which could hinder evacuation in the event of an emergency.

# DATES:

This AD becomes effective April 25, 2012.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of April 25, 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:

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 October 19, 2011 (76 FR 64849), and proposed to correct an unsafe condition for the specified products. The MCAI states:                

Several operators have reported difficulties in opening the airstair door. Investigation revealed that the airstair door gearbox drain paths were blocked by sealant, causing water to accumulate and freeze in the gearbox assembly. An airstair door that is unable to be opened could hinder evacuation in the event of an emergency.

This [Canadian] directive mandates a one-time [general visual] inspection [for sealant blockages] and [removal of any] sealant interfering with the airstair gearbox drain paths.

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. The commenter, Air Line Pilots Association, International, supports the NPRM (76 FR 64849, October 19, 2011).

## Conclusion

We reviewed the available data, including the comment received, and determined that air safety and the public interest require adopting the AD as proposed, except for minor editorial changes. We have determined that these minor changes:
    - Are consistent with the intent that was proposed in the NPRM ( 76 FR 64849 , October 19, 2011) for correcting the unsafe condition; and
    - Do not add any additional burden upon the public than was already proposed in the NPRM ( 76 FR 64849 , October 19, 2011).

## Costs of Compliance

We estimate that this AD will affect about 83 products of U.S. registry. We also estimate that it will take about 2 work-hours per product to comply with the basic requirements of this AD. The average labor rate is $85 per work-hour. 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 $14,110, or $170 per product.

In addition, we estimate that any necessary follow-on actions would take about 3 work-hours and require parts costing $0, for a cost of $255. We have no way of determining the number of products that may need these actions.

## 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 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.

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 64849, October 19, 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: 

**2012-06-04 Bombardier, Inc.:**                             Amendment 39-16985. Docket No. FAA-2011-1088; Directorate Identifier 2011-NM-099-AD.                                  ( print page 16430)    

## (a) Effective Date

This airworthiness directive (AD) becomes effective April 25, 2012.

## (b) Affected ADs

None.

## (c) Applicability

This AD applies to Bombardier, Inc. Model DHC-8-400, -401, and -402 airplanes; certificated in any category; serial numbers 4161 through 4296 inclusive.

## (d) Subject

Air Transport Association (ATA) of America Code 53: Fuselage.

## (e) Reason

This AD was prompted by reports of difficulties in opening the airstair door. We are issuing this AD to detect and correct drain paths blocked by sealant, resulting in an airstair door that is unable to be opened, which could hinder evacuation in the event of an emergency.

## (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 600 flight hours after the effective date of this AD, do a general visual inspection of the structure and gearbox drain paths for blockages by sealant, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-53-48, dated December 2, 2010. If any blockages are found, before further flight, remove blockages, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-53-48, dated December 2, 2010.

## (h) 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.                        

## (i) Related Information

Refer to MCAI Canadian Airworthiness Directive CF-2011-06, dated April 26, 2011; and Bombardier Service Bulletin 84-53-48, dated December 2, 2010; for related information.

## (j) 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 84-53-48, dated December 2, 2010.

                            (2) For service information identified in this AD, contact Bombardier, Inc., Q-Series Technical Help Desk, 123 Garratt Boulevard, Toronto, Ontario M3K 1Y5, Canada; telephone 416-375-4000; fax 416-375-4539; email                             *thd.qseries@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 March 9, 2012.

Ali Bahrami

Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 2012-6531 Filed 3-20-12; 8:45 am]

BILLING CODE 4910-13-P