AD 98-20-24

This amendment adopts a new airworthiness directive (AD), applicable to certain Dornier Model 328-100 series airplanes, that requires a one-time inspection of direct current (DC) power unit 1VE to determine whether electrical connections are correctly installed and stud nuts are correctly torqued, and corrective actions, if necessary. For certain airplanes, this amendment also requires replacement of the existing DC power unit 1VE with a modified DC power unit. 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 overheating of electrical connections, which could result in electrical arcing and consequent fire.

Final rule

98-20-24 DORNIER LUFTFAHRT GmbH: Amendment 39-10790. Docket 98-NM-96-AD.
Applicability: Model 328-100 series airplanes, as listed in Dornier Alert Service Bulletin ASB-328-24-021, dated November 25, 1997; or Dornier Alert Service Bulletin ASB-328-24-018, dated August 5, 1997; 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 overheating of electrical connections, which could result in electrical arcing and consequent fire, accomplish the following:

(a) For airplanes listed in Dornier Alert Service Bulletin ASB-328-24-018, dated August 5, 1997: Within 10 days after the effective date of this AD, perform the actions required by paragraphs (a)(1) and (a)(2) of this AD, in accordance with Dornier Alert Service Bulletin ASB-328-24-018, dated August 5, 1997.

(1) Perform a one-time visual inspection of direct current (DC) power unit 1VE to determine whether electrical connections are installed correctly, in accordance with the Accomplishment Instructions of the alert service bulletin. If any discrepancy is detected, prior to further flight, install the connections in accordance with Figure 1 of the alert service bulletin.

(2) Perform a one-time torque inspection of the stud nuts of DC power unit 1VE to determine whether they are torqued correctly, in accordance with the Accomplishment Instructions of the alert service bulletin. If any discrepancy is found, prior to further flight, torque in accordance with Table 1 of the alert service bulletin.

(b) For airplanes listed in Dornier Alert Service Bulletin ASB-328-24-021, dated November 25, 1997: Within 10 days after the effective date of this AD, replace the existing DC power unit 1VE with a modified DC power unit, in accordance with Dornier Alert Service Bulletin ASB-328-24-021, dated November 25, 1997.

NOTE 2: Dornier Alert Service Bulletin 328-24-021, dated November 25, 1997, refers to l'Equipement et la Construction Electrique Alert Service Bulletin ASB 230GC02Y-24-001, dated November 24, 1997, as an additional source of service information for accomplishing the modification of the DC power unit.

(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, International Branch, ANM-116, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116

(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.

(e) The actions shall be done in accordance with Dornier Alert Service Bulletin ASB-328-24-018, dated August 5, 1997, or Dornier Alert Service Bulletin ASB-328-24-021, dated November 25, 1997, as applicable. 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 FAIRCHILD DORNIER, DORNIER Luftfahrt GmbH, P.O. Box 1103, D-82230 Wessling, Germany. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; 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 German airworthiness directive 97-322, dated November 20, 1997; and German airworthiness directive 97-354, dated December 18, 1997.

(f) This amendment becomes effective on October 27, 1998.

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 Dornier Model 328-100 series airplanes was published in the Federal Register on July 7, 1998 (63 FR 36624). That action proposed to require a one-time inspection of the direct current (DC) power unit 1VE to determine whether electrical connections are correctly installed and stud nuts are correctly torqued, and corrective actions, if necessary. For certain airplanes, that action also proposed to require replacement of the existing DC power unit 1VE with a modified DC power unit.

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the single comment received.

The commenter, the manufacturer, requests that the FAA withdraw the proposed rule. The commenter submits data reflecting the compliance status of all affected airplanes, which indicate that all U.S.-registered airplanes are in compliance with the proposed requirements of the AD.

The FAA does not concur with the commenter s request to withdraw the proposed AD. The data submitted by the commenter indicate that some airplanes of foreign registry do not comply with the requirements of the AD. If any airplane of foreign registry were to be placed on the U.S. Register in the future, that airplane would be required to be in compliance with the inspections and modifications specified in this AD. Issuance of this AD is the appropriate vehicle to ensure that the required inspection and modification are accomplished on such an airplane prior to entry into the U.S.

Conclusion
After careful review of the available data, including the comments noted above, 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 50 Dornier Model 328-100 series airplanes of U.S. registry will be affected by this AD.

It will take approximately 1 work hour per airplane to accomplish the required inspection, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the required inspection on U.S. operators is estimated to be $3,000, or $60 per airplane.

It will take approximately 4 work hours per airplane to accomplish the required replacement, at an average labor rate of $60 per work hour. Required parts will be provided by the manufacturer at no cost to operators. Based on these figures, the cost impact of the required replacement on U.S. operators is estimated to be $12,000, or $240 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: