E7-2411. Airworthiness Directives; Bombardier Model DHC-8-400 Series Airplanes

AGENCY:

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

ACTION:

Final rule.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for certain Bombardier Model DHC-8-400 series airplanes. This AD requires inspecting to determine the manufacturer's date of certain V-band clamps on the engine exhaust shroud assembly, and doing related investigative/corrective actions if necessary. This AD results from a report of a discrepancy found during a maintenance inspection on a V-band clamp located on the engine exhaust duct shroud. The clamp ends were touching (although the correct fastener torque had been applied), resulting in reduced clamp force on the flanges. We are issuing this AD to prevent vibration in the duct shroud and fretting of the V-band clamp and flanges, which could result in cracking of the flanges and consequent release of hot exhaust gases from the engine tailpipe and damage to adjacent structure. This situation could trigger the fire warning system and result in an in-flight emergency, such as the flightcrew shutting down the engine and activating the fire suppression system.

DATES:

This AD becomes effective March 21, 2007.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of March 21, 2007.

ADDRESSES:

You may examine the AD docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC.

Contact Bombardier, Inc., Bombardier Regional Aircraft Division, 123 Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada, for service information identified in this AD.

FOR FURTHER INFORMATION CONTACT:

Richard Fiesel, 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:

Examining the Docket

You may examine the airworthiness directive (AD) docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone [phone]) is located on the plaza level of the Nassif Building at the street address stated in the ADDRESSES section.

Discussion

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to certain Bombardier Model DHC-8-400 series airplanes. That NPRM was published in the Federal Register on November 3, 2006 (71 FR 64651). That NPRM proposed to require inspecting to determine the manufacturer's date of certain V-band clamps on the engine exhaust shroud assembly, and doing related investigative/corrective actions if necessary.

Comments

We provided the public the opportunity to participate in the development of this AD. We received no comments on the NPRM or on the determination of the cost to the public.

Conclusion

We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed.

Costs of Compliance

This AD affects about 21 airplanes of U.S. registry. The required actions take about 3 work hours per airplane, at an average labor rate of $80 per work hour. Required parts cost is minimal. Based on these figures, the estimated cost of this AD for U.S. operators is $5,040, or $240 per airplane.

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 have 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 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. See the ADDRESSES section for a location to examine the regulatory evaluation.

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 Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

2007-04-07 Bombardier, Inc. (Formerly de Havilland, Inc.): Amendment 39-14938. FAA-2006-26241; Directorate Identifier 2006-NM-155-AD.

Effective Date

(a) This AD becomes effective March 21, 2007.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Bombardier Model DHC-8-400 series airplanes, certificated in any category; as identified in Bombardier Service Bulletin 84-78-01, Revision ‘A,' dated September 15, 2005.

Unsafe Condition

(d) This AD results from a report of a discrepancy found during a maintenance inspection on a V-band clamp located on the engine exhaust duct shroud. The clamp ends were touching (although the correct fastener torque had been applied), resulting in reduced clamp force on the flanges. We are issuing this AD to prevent vibration in the duct shroud and fretting of the V-band clamp and flanges, which could result in cracking of the flanges and consequent release of hot exhaust gases from the engine tailpipe and damage to adjacent structure. This situation could trigger the fire warning system and result in an in-flight emergency, such as the flightcrew shutting down the engine and activating the fire suppression system.

Compliance

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

Inspection/Investigative and Corrective Actions

(f) Within 5,000 flight hours after the effective date of this AD: Inspect to determine the part number (P/N) of the V-band clamps on the engine exhaust duct shroud in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-78-01, Revision ‘A,' dated September 15, 2005. For any V-band clamp having P/N VC1642A-2030-A or VC1642A-1875-A, before further flight, determine the manufacturer's date and do all applicable related investigative and corrective actions (including inspecting the flange of the shroud assemblies for discrepancies), by accomplishing all the actions specified in the Accomplishment Instructions of the service bulletin; except as provided by paragraph (g) of this AD. Do all applicable related investigative and corrective actions before further flight.

(g) If, during the accomplishment of the corrective actions required by paragraph (f) of this AD, the service bulletin specifies contacting the manufacturer for repair instructions, before further flight, repair in accordance with a method approved by either the Manager, New York Aircraft Certification Office (ACO), FAA; or Transport Canada Civil Aviation (TCCA) (or its delegated agent).

Actions Accomplished According to Previous Issue of Service Bulletin

(h) Actions accomplished before the effective date of this AD according to Bombardier Service Bulletin 84-78-01, dated March 22, 2005, are considered acceptable for compliance with the corresponding actions specified in paragraph (f) of this AD.

Parts Installation

(i) As of the effective date of this AD, no person may install a V-band clamp, P/N VC1642A-2030-A or VC1642A-1875-A, with a manufacturer batch stamp dated before “08-02,” on any airplane.

Alternative Methods of Compliance (AMOCs)

(j)(1) The Manager, New York ACO, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(2) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office.

Related Information

(k) Canadian airworthiness directive CF-2006-06, dated April 4, 2006, also addresses the subject of this AD.

Material Incorporated by Reference

(l) You must use Bombardier Service Bulletin 84-78-01, Revision ‘A,' dated September 15, 2005, to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference of this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Bombardier, Inc., Bombardier Regional Aircraft Division, 123 Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada, for a copy of this service information. You may review copies at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., Room PL-401, Nassif Building, Washington, DC; on the Internet at http://dms.dot.gov;​; or at the National Archives and Records Administration (NARA). For information on the availability of this material at the NARA, call [phone], or go to http://www.archives.gov/​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html.

Issued in Renton, Washington, on February 2, 2007.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.