AD 2006-07-16

The FAA is adopting a new airworthiness directive (AD) for certain Bombardier Model DHC-8-400 series airplanes. This AD requires replacing all domed anchor nuts at all attachment locations of the upper fuel access panels of the center wing in the wet bay location with new nuts. This AD results from reported cases of corroded dome anchor nuts at the attachment locations of the upper surface of the fuel access panel of the center wing. We are issuing this AD to prevent corrosion or perforation of domed anchor nuts, which could result in arcing and ignition of fuel vapor in the center wing fuel tank during a lightning strike and consequent explosion of the fuel tank.

Final rule.

2006-07-16 Bombardier, Inc. (Formerly de Havilland, Inc.): Amendment 39-14543. Docket No. FAA-2006-23798; Directorate Identifier 2005-NM- 162-AD.

Effective Date

(a) This AD becomes effective May 12, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Bombardier Model DHC-8-400 series airplanes, certificated in any category; serial numbers 4001, and 4003 through 4115 inclusive.

Unsafe Condition

(d) This AD results from reported cases of corroded dome anchor nuts at the attachment locations of the upper surface of the fuel access panel of the center wing. We are issuing this AD to prevent corrosion or perforation of domed anchor nuts, which could result in arcing and ignition of fuel vapor in the center wing fuel tank during a lightning strike and consequent explosion of the fuel tank.

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.

Replacement With Corrosion Resistant Anchor Nuts

(f) At the applicable time in Table 1 of this AD, replace all domed anchor nuts at all attachment locations of the upper fuel access panels of the center wing in the wet bay location with new, corrosion-resistant anchor nuts. Do all the actions in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-57-10, Revision "A," dated March 14, 2005.

Table 1.--Compliance Time

For airplanes having serial number(s)
On which the inspection(s) specified in
Do the replacement

(1) 4108 through 4115 inclusive
None
Within 48 months after the date of issuance of the original standard Canadian airworthiness certificate or the date of issuance of the original Canadian export certificate of
airworthiness, or within 2 months after the effective date of this AD, whichever occurs later.

Bombardier Service Bulletin 84 57 11, dated February 25, 2005; or Revision 'A,'dated March 9, 2005; have been done before the effective date of this AD.
Within 24 months after those inspections, or within 2 months after the effective date of this AD, whichever occurs later.

Bombardier Service Bulletin 84 57 12, dated March 11, 2005, has been done before the effective date of this AD.
Within 48 months after that inspection, or within 2 months after the effective date of this AD, whichever occurs later.

(2) 4001, and 4003 through 4107 inclusive ......
Bombardier Service Bulletin 84 57 11, dated February 25, 2005, or Revision 'A,'dated March 9, 2005; or Bombardier Service Bulletin 84 57 12, dated March 11, 2005; has not been done before the effective date of this AD.
Within 3 months after the effective date of this
AD.

Alternative Methods of Compliance (AMOCs)

(g)(1) The Manager, New York Aircraft Certification Office, FAA, 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 Sec. 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

(h) Canadian airworthiness directive CF-2005-08R1, dated August 10, 2005, also addresses the subject of this AD.

Material Incorporated by Reference

(i) You must use Bombardier Service Bulletin 84-57-10, Revision `A,' dated March 14, 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 (202) 741-6030, or go to http://www.archives. gov/federal -- register/ code --of -- federal --
regulations/ ibr-- locations. html.

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 (800) 647-5227) 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 February 8, 2006 (71 FR 6411). That NPRM proposed to require replacing all domed anchor nuts at all attachment locations of the upper fuel access panels of the center wing in the wet bay location with new nuts.

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.

Change to NPRM

We have revised the telephone number in the FOR FURTHER INFORMATION CONTACT paragraph.

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 will affect about 20 airplanes of U.S. registry. The required actions will take about 62 work hours per airplane, at an average labor rate of $65 per work hour. Required parts will cost about $300 per airplane. Based on these figures, the estimated cost of the AD for U.S. operators is $86,600, or $4,330 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.

Sec. 39.13 [Amended]

2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by adding the following new airworthiness directive (AD):