AD 2000-19-07

This amendment adopts a new airworthiness directive (AD), applicable to certain EMBRAER Model EMB-120, EMB-120ER, and EMB-120RT series airplanes, that requires removal of a certain fastener, if applicable, and sealing of the corresponding fastener hole. This action is necessary to prevent contact between one of the bolts that attaches the direct current (DC) relay box on the left-hand side of the airplane and one of the power terminals of electrical emergency contactor 2, which could result in a short circuit in the DC relay box, and consequent partial loss of the electrical system, and degraded operation of airplane systems. This action is intended to address the identified unsafe condition.

Final rule

2000-19-07 EMPRESA BRASILEIRA DE AERONAUTICA S.A. (EMBRAER): Amendment 39-11908. Docket 2000-NM-122-AD.

Applicability: Model EMB-120, EMB-120ER, and EMB-120RT series airplanes; serial numbers 120004 and 120006 through 120321 inclusive; certificated in any category; on which EMBRAER Service Bulletin 120-24-0051, dated March 1, 1994; Revision 1, dated May 5, 1994; Revision 2, dated May 31, 1994; Revision 3, dated November 3, 1994; Revision 4, dated March 8, 1995; or the production equivalent, has been accomplished.

Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise 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) ofthis 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 contact between one of the bolts that attaches the direct current (DC) relay box on the left-hand (LH) side of the airplane (hereinafter referred to as the "LH DC relay box") and one of the power terminals of electrical emergency contactor 2 (K0519), which could result in a short circuit in the LH DC relay box, and consequent partial loss of the electrical system, and degraded operation of airplane systems, accomplish the following:

Bolt/Washer Removal and Hole Sealing
(a) Within 75 flight hours after the effective date of this AD, remove the bolt and washer on the LH DC relay box that is in the area of electrical emergency contactor 2 (K0519) and seal the corresponding fastener hole, in accordance with EMBRAER Alert Service Bulletin 120-24-A057, dated November 14, 1996. If no fastener is installed, seal the corresponding fastener hole only, in accordance with the alert service bulletin.

Alternative Methods of Compliance
(b) 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, Atlanta Aircraft Certification Office (ACO), FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Atlanta ACO.

Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta 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 EMBRAER Alert Service Bulletin 120-24-A057, dated November 14, 1996. 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 Empresa Brasileira de Aeronautica S.A. (EMBRAER), P.O. Box 343 - CEP 12.225, Sao Jose dos Campos - SP, Brazil. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Note 3: The subject of this AD is addressed in Brazilian airworthiness directive 96-12-02, dated December 13, 1996.

Effective Date
(e) This amendment becomes effective on October 31, 2000.

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 EMBRAER Model EMB-120, EMB-120ER, and EMB-120RT series airplanes was published in the Federal Register on June 27, 2000 (65 FR 39576). That action proposed to require removal of a certain fastener, if applicable, and sealing of the corresponding fastener hole.

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 240 airplanes of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $14,400, or $60 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. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact
The regulations adopted herein 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 variouslevels of government. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.

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: