[Federal Register Volume 61, Number 66 (Thursday, April 4, 1996)]
[Proposed Rules]
[Pages 15000-15002]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-8294]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-231-AD]


Airworthiness Directives; Dornier Model 328-100 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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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 replacement of a bus 
power control unit (BPCU) and two generator control units (GCU) with 
new improved units. This proposal is prompted by results of the 
manufacturer's re-certification and laboratory testing of a BPCU, which 
revealed abnormal functions of the BPCU and the GCU. The actions 
specified by the proposed AD are intended to prevent such abnormal 
functions, which could result in electrical short circuits in the 
electrical power distribution systems and a subsequent fire.

DATES: Comments must be received by May 15, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-231-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 Dornier Luftfahrt GmbH, P.O. Box 1103, D-82230 Wessling, 
Germany. This information may be examined at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Gary Lium, Aerospace Engineer,

[[Page 15001]]
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-1112; fax (206) 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 filed in 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 95-NM-231-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-103, Attention: Rules 
Docket No. 95-NM-231-AD, 1601 Lind Avenue SW., Renton, Washington 
98055-4056.

Discussion

    The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority 
for Germany, recently notified the FAA that an unsafe condition may 
exist on certain Dornier Model 328-100 series airplanes. The LBA 
advises that results of the manufacturer's re-certification and 
laboratory testing of an upgraded/modified bus powered control unit 
(BPCU) revealed certain abnormal functions. These abnormalities include 
extended duration of the transfer of the essential bus (ESS BUS), 
chattering of contacts, and various problems that occurred during a 
cold cross start. Subsequent observations also revealed abnormal 
functions of two generator control units (GCU); these abnormalities 
included unsatisfactory engine starting with reduced battery voltage, 
and improper separation of the DC generator. Such abnormal functioning, 
if not corrected, could cause electrical short circuits in the 
electrical power distribution systems, and a subsequent fire.
    Dornier has issued Service Bulletin SB-328-24-061, Revision 1, 
dated November 3, 1994, which describes procedures for replacement of 
GCU's 2PC and 12PC with new improved units having part number 118-000-
1. The service bulletin also describes procedures for replacement of 
BPCU 20PC with a new improved unit having part number 106-000-3. The 
LBA classified this service bulletin as mandatory and issued German 
airworthiness directive 94-349, dated November 14, 1994, in order to 
assure the continued airworthiness of these airplanes in Germany.
    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.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design, the 
proposed AD would require replacement of the GCU's 2PC and 12PC with 
new improved units having part number 118-000-1. The proposed AD would 
also require replacement of the BPCU 20PC with a new improved unit 
having part number 106-000-3. The actions would be required to be 
accomplished in accordance with the service bulletin described 
previously.
    The FAA estimates that 12 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 1 work 
hours per airplane to accomplish the proposed actions, and that the 
average labor rate is $60 per work hour. The manufacturer would provide 
required parts at no cost to the operators. Based on these figures, the 
cost impact of the proposed AD on U.S. operators is estimated to be 
$720, or $60 per airplane.
    The cost impact figure discussed above is 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.
    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.
    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 USC 106(g), 40113, 44701.


Sec. 39.13  [Amended]

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

Dornier: Docket 95-NM-231-AD.

    Applicability: Model 328-100 series airplanes having serial 
numbers 3005 through 3024 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

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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 abnormal functions of the bus power control units and 
the generator control units, which could result in electrical short 
circuits in the electrical power distribution systems and a 
subsequent fire; accomplish the following:
    (a) Within 3 months after the effective date of this AD, perform 
the requirements of paragraph (a)(1) and (a)(2) of this AD, in 
accordance with Dornier Service Bulletin SB-328-24-061, Revision 1, 
dated November 3, 1994.
    (1) Remove the generator control units 2PC and 12PC and replace 
them with new improved units having part number 118-000-1. And,
    (2) Remove bus power control unit 20PC and replace it with a new 
improved unit having part number 106-000-3.
    (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, Standardization Branch, ANM-113, 
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, 
Standardization Branch, ANM-113.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (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.

    Issued in Renton, Washington, on March 29, 1996.
Bill R. Boxwell,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-8294 Filed 4-3-96; 8:45 am]
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