AD 99-21-11

This amendment adopts a new airworthiness directive (AD), applicable to certain Bombardier Model CL-600-2B19 (Regional Jet Series 100) series airplanes, that requires a one-time inspection to detect damage of the input connectors and wiring of the main and auxiliary power unit (APU) battery chargers, and corrective action, if necessary. This amendment also requires installation of secure connectors for the battery charger input connections. In addition, this amendment requires, for certain airplanes, either the installation of a resistor in the battery charger wiring, or the installation of new batteries with internal resistors. 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 increased risk of a short circuit and consequent electrical smoke or fire in the aft fuselage.

Final rule

99-21-11 BOMBARDIER, INC. (Formerly Canadair): Amendment 39-11355. Docket 98-NM-385-AD. Issued September 29, 1999.
Applicability: Model CL-600-2B19 (Regional Jet Series 100) series airplanes, serial numbers 7003 through 7067 inclusive and 7069 through 7250 inclusive; 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 (c) 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 increased risk of a short circuit and consequent electrical smoke or fire in the aft fuselage, accomplish the following:

Inspection and Corrective Action
(a) For all airplanes: Within 450 flight hours after the effective date of this AD, accomplish the actions specified in paragraphs (a)(1), (a)(2), and (a)(3) of this AD, in accordance with Part A of the Accomplishment Instructions of Canadair Alert Service Bulletin A601R-24-085, Revision `C,' dated November 5, 1998.

(1) Perform a detailed visual inspection to detect damage of the input connector of the main battery charger and the wire harness between the electrical connectors for the main battery and the main battery charger. If any damage is detected, prior to further flight, repair it, or replace the wiring or connector with new or serviceable parts.

(2) Perform a detailed visual inspection to detect damage of the input connector of the auxiliary power unit (APU) battery charger and the wire harness between the electrical connectors for the APU battery and the APU battery charger. If any damage is detected, prior to further flight, repair it, or replace the wiring or connector with new or serviceable parts.

(3) Secure both the spin coupling ring of the input connector of the main battery charger and the spin coupling ring of the input connector of the APU battery charger by installing heat shrink tubing and ty-rap.

NOTE 2: For the purposes of this AD, a detailed visual inspection is defined as: "An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc. may be used. Surface cleaning and elaborate access procedures may be required."

Modification or Replacement
(b) For airplane serial numbers 7003 through 7067 inclusive and 7069 through 7249 inclusive: Within 450 flight hours after the effective date of this AD, accomplish the actions in either paragraph (b)(1) or (b)(2) in accordance with Part B of the Accomplishment Instructions of Canadair Alert Service Bulletin A601R-24-085, Revision `C,' dated November 5, 1998.

(1) Install an external 5.1-Kohm resistor in the mid-voltage sensing wire for the main battery and an external 5.1-Kohm resistor in the mid-voltage sensing wire for the APU battery. Or

(2) Install main battery P/N 601R59041-3 and APU battery P/N 600-59151-11, which contain an internal resistor for the mid-voltage sensing wire.

Alternative Methods of Compliance
(c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, NewYork 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
(d) 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
(e) The actions shall be done in accordance with Canadair Alert Service Bulletin A601R-24-085, Revision `C,' dated November 5, 1998. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Bombardier, Inc., Canadair, Aerospace Group, P.O. Box 6087, Station Centre-ville, Montreal, Quebec H3C 3G9, 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-98-40, dated November 10, 1998.

(f) This amendment becomes effective on November 12, 1999.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Bombardier Model CL-600-2B19 (Regional Jet Series 100) series airplanes was published in the Federal Register on August 12, 1999 (64 FR 43957). That action proposed to require a one-time inspection to detect damage of the input connectors and wiring of the main and auxiliary power unit (APU) battery chargers, and corrective action, if necessary. It also proposed to require installation of secure connectors for the battery charger input connections. In addition, that action proposed to require, for certain airplanes, either the installation of a resistor in the battery charger wiring, or the installation of new batteries with internal resistors.

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 to the public.

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

Cost Impact
The FAA estimates that 115 airplanes of U.S. registry will be affected by this AD. It will take approximately 6 work hours per airplane to accomplish the required actions (no breakdown of work hours for each action is provided in the service bulletin), at an average labor rate of $60 per work hour. Required parts will be provided at no cost to the operators. Based on these figures, the cost impact of the required AD on U.S. operators is estimated to be $41,400, or $360 per airplane.

The cost impact figure discussed above is 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 adding the following new airworthiness directive: