AD 99-21-09

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Bombardier Model DHC-8-102, -103, -106, -201, -202, -301, -311, and -315 series airplanes, that currently requires a one-time inspection to detect chafing of electrical wires in the cable trough below the cabin floor; repair, if necessary; installation of additional tie-mounts and tie-wraps; and application of sealant to rivet heads. This amendment requires the accomplishment of these same actions on additional airplanes. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent chafing of electrical wires, which could result in an uncommanded shutdown of an engine during flight.

Final Rule

99-21-09 BOMBARDIER, INC. (Formerly de Havilland, Inc.): Amendment 39-11352. Docket 98-NM-32-AD. Supersedes AD 98-20-14, Amendment 39-10781.

Applicability: Model DHC-8-102, -103, -106, -201, -202, -301, -311, and -315 series airplanes; serial numbers 3 through 540 inclusive, excluding serial number 462; certificated in any category.

NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent chafing of electrical wires, which could result in an uncommanded shutdown of an engine during flight, accomplish the following:

One-time Inspection, Corrective Action, and Modification

(a) Perform a one-time general visual inspection to detect chafing of electrical wires in the cable trough below the cabin floor; install additional tie-mounts and tie-wraps; and apply sealant to rivet heads (reference Bombardier Modification 8/2705); in accordance with Bombardier Service Bulletin S.B. 8-53-66, dated March 27, 1998, at the time specified in paragraph (a)(1) or (a)(2) of this AD, as applicable. If any chafing is detected during the inspection required by this paragraph, prior to further flight, repair in accordance with the service bulletin.

NOTE 2: For the purposes of this AD, a general visual inspection isdefined as: "A visual examination of an interior or external area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light, and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked."

(1) For airplanes having serial numbers 3 through 519 inclusive, excluding serial number 462: Inspect within 36 months after October 27, 1998 (the effective date of AD 98-20-14, amendment 39-10781).

(2) For airplanes having serial numbers 520 through 540 inclusive: Inspect within 36 months after the effective date of this AD, or at the next "C" check, whichever occurs first.

Alternative Methods of Compliance

(b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may beused if approved by the Manager, New York Aircraft Certification Office (ACO), FAA, Engine and Propeller Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, New York ACO.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the New York ACO.

Special Flight Permits

(c) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Incorporation by Reference

(d) The actions shall be done in accordance with Bombardier Service Bulletin S.B. 8-53-66, dated March 27, 1998. This incorporation by reference was approved previously by the Director of the Federal Register as of October 27, 1998 (63 FR 50501, September 22, 1998). Copies may be obtained from Bombardier, Inc., Bombardier Regional Aircraft Division, Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Engine and Propeller Directorate New York Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New York; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

NOTE 4: The subject of this AD is addressed in Canadian airworthiness directive CF-98-08R1, dated September 16, 1998.

(e) This amendment becomes effective on November 10, 1999.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 98-20-14, amendment 39-10781 (63 FR 50501, September 22, 1998), which is applicable to certain Bombardier Model DHC-8-102, -103, -106, -201, -202, -301, -311, and -315 series airplanes, was published in the Federal Register on August 12, 1999 (64 FR 43948). The action proposed to supersede AD 98-20-14 to continue to require a one-time inspection to detect chafing of electrical wires in the cable trough below the cabin floor; repair, if necessary; installation of additional tie-mounts and tie-wraps; and application of sealant to rivet heads. That action also proposed to expand the applicability of the existing AD to include additional airplanes.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA s determination of the cost tothe public.

Conclusion

The FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

Cost Impact

There are approximately 231 Bombardier Model DHC-8-102, -103, -106, -201, -202, -301, -311, and -315 series airplanes of U.S. registry that will be affected by this AD.

The actions specified in this AD are currently required by AD 98-20-14, which is applicable to 210 Model DHC-8-102, -103, -106, -201, and -202 series airplanes. For these airplanes, it takes approximately 70 work hours per airplane to accomplish the required actions, at an average labor rate of $60 per work hour. Required parts are provided by the manufacturer at no cost to the operators. Based on these figures, the cost impact of the current requirements of AD 98-20-14 on U.S. operators of these airplanes is estimated to be $882,000, or $4,200 per airplane. The AD will add no new costs for these airplanes.

The actions specified in this AD are currently required by AD 98-20-14, which is applicable to 15 Model DHC-8-301, -311, and -315 series airplanes. For these airplanes, it takes approximately 100 work hours per airplane to accomplish the required actions, at an average labor rate of $60 per work hour. Required parts will be provided by the manufacturer at no cost to the operators. Based on these figures, the cost impact of the current requirements of AD 98-20-14 on U.S. operators of these airplanes is estimated to be $90,000, or $6,000 per airplane.

The actions specified in this AD will be applicable to 6 additional Model DHC-8-301, -311, and -315 series airplanes of U.S. registry and will take approximately 100 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will be provided by the manufacturer at no cost to the operator. Based on these figures, cost impact of the action required by this AD on U.S. operators of these 6 additional airplanes is estimated to be $36,000, orapproximately $6,000 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

Regulatory Impact

The regulations adopted herein will not have substantial direct effects 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. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by removing amendment 39-10781 (63 FR 50501, September 22, 1998), and by adding a new airworthiness directive (AD), amendment 39-11352, to read as follows: