E7-25613. Airworthiness Directives; Viking Air Limited Model (Caribou) DHC-4 and (Caribou) DHC-4A Airplanes

AGENCY:

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

ACTION:

Final rule; request for comments.

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:

During a heavy maintenance check on a DHC-4 aircraft, an operator discovered that both of the upper engine mount bracket assemblies on one aircraft were cracked. Further inspection of the operator's fleet confirmed that engine mount bracket assemblies on five out of ten aircraft were also cracked.

* * * * *

Failure of the upper engine mount bracket assembly could result in separation of the engine from the airplane. This AD requires actions that are intended to address the unsafe condition described in the MCAI.

DATES:

This AD becomes effective January 23, 2008.

The Director of the Federal Register approved the incorporation by reference of a certain publication, listed in the AD as of January 23, 2008.

We must receive comments on this AD by February 7, 2008.

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: [phone].
• 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 W12-40, 1200 New Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

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 this AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

George Duckett, Aerospace Engineer, Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New York 11590; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Discussion

Transport Canada Civil Aviation (TCCA), which is the aviation authority for Canada, has issued Canadian Airworthiness Directive CF-2007-26, dated November 7, 2007 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:

During a heavy maintenance check on a DHC-4 aircraft, an operator discovered that both of the upper engine mount bracket assemblies on one aircraft were cracked. Further inspection of the operator's fleet confirmed that engine mount bracket assemblies on five out of ten aircraft were also cracked.

As an interim action to prevent failure of upper engine mount bracket assemblies, this directive mandates a one-time fluorescent penetrant inspection. Subsequent corrective action may be implemented in the future pending results of the investigation.

Failure of the upper engine mount bracket assembly could result in separation of the engine from the airplane. Corrective actions include replacing any cracked engine mount bracket assembly with a new assembly. You may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

Viking Air Limited has issued Alert Service Bulletin V4/0001, dated November 9, 2007. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI.

FAA's Determination and Requirements of This 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 issuing this AD because we evaluated all pertinent information and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design.

Differences Between the 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 FAA policies. Any such differences are highlighted in a NOTE within the AD.

FAA's Determination of the Effective Date

An unsafe condition exists that requires the immediate adoption of this AD. The FAA has found that the risk to the flying public justifies waiving notice and comment prior to adoption of this rule because failure of the upper engine mount bracket assembly could lead to separation of the engine from the airplane. Therefore, we find that notice and opportunity for prior public comment hereon are impracticable and that good cause exists for making this amendment effective in less than 30 days.

Comments Invited

This AD is a final rule that involves requirements affecting flight safety, and we did not precede it by notice and opportunity for public comment. We invite you to send any written relevant data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2008-0410; Directorate Identifier 2007-NM-338-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of 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 AD.

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.

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

[Amended]

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

2008-01-02 Viking Air Limited (Formerly Bombardier, Inc.): Amendment 39-15325. Docket No. FAA-2008-0410; Directorate Identifier 2007-NM-338-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective January 23, 2008.

Affected ADs

(b) None.

Applicability

(c) This AD applies to all Viking Air Limited Model (Caribou) DHC-4 and (Caribou) DHC-4A airplanes, certificated in any category.

Subject

(d) Air Transport Association (ATA) of America Code 54: Nacelles/Pylons.

Reason

(e) The mandatory continued airworthiness information (MCAI) states:

“During a heavy maintenance check on a DHC-4 aircraft, an operator discovered that both of the upper engine mount bracket assemblies on one aircraft were cracked. Further inspection of the operator's fleet confirmed that engine mount bracket assemblies on five out of ten aircraft were also cracked.

“As an interim action to prevent failure of upper engine mount bracket assemblies, this directive mandates a one-time fluorescent penetrant inspection. Subsequent corrective action may be implemented in the future pending results of the investigation.”

Failure of the upper engine mount bracket assembly could result in separation of the engine from the airplane. Corrective actions include replacing any cracked engine mount bracket assembly with a new assembly.

Actions and Compliance

(f) Unless already done, do the following actions.

(1) Within 10 flight hours after the effective date of this AD, do a fluorescent penetrant inspection (FPI) for cracking of the upper engine mount bracket assemblies having part numbers C4WM1090-1 and C4WM1090-2, in accordance with the Accomplishment Instructions of Viking Alert Service Bulletin V4/0001, dated November 9, 2007. Before further flight, replace any cracked engine mount bracket assembly with a new engine mount bracket assembly, in accordance with the Accomplishment Instructions of the alert service bulletin.

(2) Within 7 days after completing the inspection required by paragraph (f)(1) of this AD or within 30 days after the effective date of this AD, whichever occurs later, report any crack found to: Viking Technical Support, E-mail: [e-mail]; telephone [phone]; toll free 1-800-663-8444; fax [phone].

(3) Actions done before the effective date of this AD in accordance with Viking All Operators Message 2007-4-11-02, Revision A, dated November 5, 2007, are considered acceptable for compliance with the requirements of this AD.

FAA AD Differences

Note:

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

Other FAA AD Provisions

(g) The following provisions also apply to this AD:

(1) Alternative Methods of Compliance (AMOCs): The Manager, New York Aircraft Certification Office, 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: George Duckett, Aerospace Engineer, Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New York 11590; telephone [phone]; fax [phone]. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.

(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.

(3) Reporting Requirements: For any reporting requirement in this AD, under the provisions of the Paperwork Reduction Act, the Office of Management and Budget (OMB) has approved the information collection requirements and has assigned OMB Control Number 2120-0056.

Related Information

(h) Refer to MCAI Canadian Airworthiness Directive CF-2007-26, dated November 7, 2007; Viking All Operators Message 2007-4-11-02, Revision A, dated November 5, 2007; and Viking Alert Service Bulletin V4/0001, dated November 9, 2007; for related information.

Material Incorporated by Reference

(i) You must use Viking Alert Service Bulletin V4/0001, dated November 9, 2007, 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 Viking Air Limited, 9574 Hampden Road, Sidney, British Columbia V8L 5V5, Canada.

(3) You may review copies at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call [phone], or go to: http://www.archives.gov/​federal-register/​cfr/​ibr-locations.html.

Issued in Renton, Washington, on December 20, 2007.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.