[Federal Register Volume 63, Number 76 (Tuesday, April 21, 1998)]
[Proposed Rules]
[Pages 19689-19691]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-10485]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-89-AD]
RIN 2120-AA64


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 a one-time inspection to 
detect discrepancies of circuit breaker panels 10VE and 11VE; follow-on 
corrective actions; modification of the contact points; and 
installation of a high capacity fuse. This proposal would also require 
replacement of power relays 32HB and 36HB on relay panel 22VE with new 
parts. 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 
electrical short circuits of the contact points and power relays on the 
circuit breaker panels, which could result in increased risk of smoke 
and fire damage in the flight compartment.

DATES: Comments must be received by May 21, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-89-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.

[[Page 19690]]

    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 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 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 98-NM-89-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-89-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 indicating that, on certain in-service airplanes, 
signs of overheating, sparking, and burning were discovered on circuit 
breaker panels 10VE and 11VE at the back lighting contact points. These 
signs of damage may have included delamination, discoloration, pitting, 
and scorching. Investigation has revealed that an electrical short 
circuit occurred at the back lighting contact points of the circuit 
breaker panels. The cause of the electrical short circuit was 
attributed to the accumulation of moisture and condensation on the 
exposed contact points.
    In addition, the LBA advises that the pilot of a Dornier Model 328-
100 series airplane reported that the recirculation fan in the air-
conditioning system failed. The recirculation fan was mounted on relay 
panel 22VE. During investigation into the failure of the recirculation 
fan, personnel discovered that power relay 32HB, power relay 36HB, and 
a connector had melted at relay panel 22VE. Further investigation 
revealed that power relays 32HB and 36HB became hot during flight, and 
the temperature of the relays exceeded permissible levels. The cause of 
the overheating and melting was attributed to an inadequate relay 
design that could not withstand higher electrical loads than 
anticipated. These electrical short circuits, if not corrected, could 
result in increased risk of smoke and fire damage in the flight 
compartment.

Explanation of Relevant Service Information

    Dornier has issued Alert Service Bulletin ASB-328-31-016, dated 
April 2, 1997, which describes procedures for a one-time visual 
inspection to detect signs of overheating, sparking, or fire damage to 
circuit breaker panels 10VE and 11VE at the back lighting contact 
points. This alert service bulletin also describes procedures for 
replacement of any damaged circuit breaker panel with a new or 
serviceable panel, and modification of the contact points by applying 
additional sealant.
    Dornier has also issued Service Bulletin SB-328-31-226, including 
Price/Material Information Sheet, dated June 16, 1997, which describes 
procedures for modification of circuit breaker panels 10VE and 11VE by 
installing a jiffy junction (high capacity fuse assembly).
    In addition, Dornier has issued Service Bulletin SB-328-21-218, 
including Price/Material Information Sheet, dated July 2, 1997, which 
describes procedures for replacement of relays 32HB and 36HB, part 
number (P/N) DON405M520U5NL, on relay panel 22VE with new relays, P/N 
2504MY1, having a higher load capacity.
    Accomplishment of the actions specified in the service bulletins is 
intended to adequately address the identified unsafe condition. The LBA 
classified these service bulletins as mandatory and issued German 
airworthiness directives 97-136, dated May 22, 1997; 97-330, dated 
November 20, 1997; and 97-323, dated November 20, 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 
Sec. 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 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 2 work hours per airplane to accomplish 
the proposed inspection and application of sealant to the contact 
points, at an average labor rate of $60 per work hour. The cost of the 
sealant would be minimal. Based on this figure, the cost impact of the 
proposed inspection and modification on U.S. operators is estimated to 
be $120 per airplane.
    It would take approximately 1 work hour per airplane to accomplish 
the proposed installation of a high capacity fuse on the circuit 
breaker panels, 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 this figure, the cost impact of the proposed 
installation on U.S. operators is estimated to be $60 per airplane.

[[Page 19691]]

    It would take approximately 5 work hours per airplane to accomplish 
the proposed replacement of the relays, 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 this figure, the cost impact of the 
proposed replacement on U.S. operators is estimated to be $300 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.
    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-89-AD.

    Applicability: Model 328-100 series airplanes equipped with 
circuit breaker panels 10VE up to and including serial number 131, 
and 11VE up to and including serial number 133; and Model 328-100 
series airplanes, serial numbers 3005 through 3095 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 (d) 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 electrical short circuits of the contact points and 
power relays on the circuit breaker panels, which could result in 
increased risk of smoke and fire damage in the flight compartment, 
accomplish the following:
    (a) For Model 328-100 series airplanes equipped with circuit 
breaker panels 10VE up to and including serial number 131, and 11VE 
up to and including serial number 133: Within 14 days after the 
effective date of this AD, perform a one-time visual inspection to 
detect discrepancies of circuit breaker panels 10VE and 11VE at the 
back lighting contact points, in accordance with Dornier Alert 
Service Bulletin ASB-328-31-016, dated April 2, 1997.
    (1) If no discrepancy is detected, prior to further flight, 
modify the contact points by applying additional sealant in 
accordance with the alert service bulletin.
    (2) If any discrepancy is detected, prior to further flight, 
replace the damaged circuit breaker panel with a new or serviceable 
panel and modify the contact points by applying additional sealant, 
in accordance with the alert service bulletin.
    (b) For Model 328-100 series airplanes, serial numbers 3005 
through 3095 inclusive: Within 90 days after the effective date of 
this AD, install a jiffy junction fitted with a high capacity fuse 
on circuit breaker panels 10VE and 11VE, in accordance with version 
1 or version 2, as applicable, of the Accomplishment Instructions of 
Dornier Service Bulletin SB-328-31-226, including Price/Material 
Information Sheet, dated June 16, 1997.
    (c) For Model 328-100 series airplanes, serial numbers 3005 
through 3089 inclusive: Within 90 days after the effective date of 
this AD, replace relays 32HB and 36HB, part number (P/N) 
DON405M520U5NL, on relay panel 22VE with new relays, P/N 2504MY1, in 
accordance with Dornier Service Bulletin SB-328-21-218, including 
Price/Material Information Sheet, dated July 2, 1997.
    (d) 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

    (e) 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 3: The subject of this AD is addressed in German 
airworthiness directives 97-136, dated May 22, 1997; 97-330, dated 
November 20, 1997; and 97-323, dated November 20, 1997.

    Issued in Renton, Washington, on April 15, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-10485 Filed 4-20-98; 8:45 am]
BILLING CODE 4910-13-U