Airworthiness directives: Dornier,

[Federal Register: July 7, 1998 (Volume 63, Number 129)]

[Proposed Rules]

[Page 36624-36626]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr07jy98-19]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-96-AD]

RIN 2120-AA64

Airworthiness Directives; Dornier Model 328-100 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Dornier Model 328-100 series airplanes. This proposal would require 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 proposal also would require replacement of the existing DC power unit 1VE with a modified DC power unit. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to prevent overheating of electrical connections, which could result in electrical arcing and consequent fire.

DATES: Comments must be received by August 6, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-96-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays.

The service information referenced in the proposed rule may be obtained from FAIRCHILD DORNIER, DORNIER Luftfahrt GmbH, P.O. Box 1103, D-82230 Wessling, Germany. This information may be examined at the

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FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filedin the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 98-M-96-AD.'' The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-96-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, notified the FAA that an unsafe condition may exist on certain Dornier Model 328-100 series airplanes. The LBA advises that it has received reports of overheating of the electrical connection studs on direct current (DC) power unit 1VE, which has been attributed to incorrectly installed terminals and spring washers, and incorrect torquing of the stud nuts. The LBA also has received reports of overheating and burning of the mounting plate of the bus bar of the auxiliary power unit in the DC power unit 1VE, which have been attributed to an incorrectly torqued bus bar screw. Such overheating of electrical connections, if not corrected, could result in electrical arcing and consequent fire.

Explanation of Relevant Service Information

The manufacturer has issued Dornier Alert Service Bulletin ASB-328- 24-018, dated August 5, 1997. The alert service bulletin describes procedures for a one-time visual inspection of the electrical connections of DC power unit 1VE to determine whether terminals and spring washers are installed correctly, and a one-time torque inspection of the stud nuts to determine whether they are torqued correctly. Figure 1 and Table 1 of this alert service bulletin specify criteria for ensuring correct installation of the terminals and spring washers and correct torquing of the stud nuts.

The manufacturer also has issued Dornier Alert Service Bulletin ASB-328-24-021, dated November 25, 1997, which describes procedures for removing DC power unit 1VE and installing a modified DC power unit. Dornier Alert Service Bulletin ASB-328-24-021 refers to l'Equipement et la Construction Electrique (ECE) 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. That ECE alert service bulletin describes procedures for inspecting the glass mounting plate of the auxiliary power unit (APU) bus bar in the DC power unit 1VE for heat damage, installing a shim, and performing a one-time inspection of the APU bus bar screw to ensure that it is correctly torqued.

Accomplishment of the actions specified in the Dornier alert service bulletins is intended to adequately address the identified unsafe condition. The LBA classified these Dornier alert service bulletins as mandatory and issued German airworthiness directive 97- 322, dated November 20, 1997, and German airworthiness directive 97- 354, dated December 18, 1997, in order to assure the continued airworthiness of these airplanes in Germany.

FAA's Conclusions

This airplane model is manufactured in Germany and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the LBA has kept the FAA informed of the situation described above. The FAA has examined the findings of the LBA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require accomplishment of the actions specified in the Dornier alert service bulletins described previously.

Cost Impact

The FAA estimates that 50 airplanes of U.S. registry would be affected by this proposed AD.

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

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

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the proposed 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 proposed herein would 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 proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

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For the reasons discussed above, I certify that this proposed regulation (1) is not a ``significant regulatory action'' under Executive Order 12866; (2) is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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 copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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.

   Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

   Dornier Luftfahrt GmbH: 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.

   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.

   Issued in Renton, Washington, on June 30, 1998. S.R. Miller, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

   [FR Doc. 98-17957Filed7-6-98; 8:45 am]

   BILLING CODE 4910-13-P