[Federal Register Volume 61, Number 235 (Thursday, December 5, 1996)]
[Proposed Rules]
[Pages 64492-64494]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-30967]


-----------------------------------------------------------------------


DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-114-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 modification of the 
electrical circuits for certain avionics by rewiring and adding 
electrical devices. This proposal is prompted by reports indicating 
that failure of an engine or direct current (DC) generator during 
takeoff and landing, coupled with an open DC tie, could cause the 
avionics to fail. The actions specified by the proposed AD are intended 
to prevent the failure of those avionics during takeoff and landing, 
which consequently could result in the inability of the flight crew to 
respond to and control the associated systems during these critical 
phases of flight.

DATES: Comments must be received by January 17, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-114-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: Connie Beane, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-2796; 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

[[Page 64493]]

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 96-NM-114-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. 96-NM-114-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 it has received reports indicating that the failure of an 
engine or direct current (DC) generator during takeoff and landing, 
coupled with an open DC tie in the airplane's electrical system, could 
cause failure of the No. 2 primary flight and multiple function 
displays, or the autopilot/yaw damper servos. The failure of these 
avionics during takeoff and landing, if not prevented, could result in 
the inability of the flight crew to respond to and control the systems 
associated with these avionics during these critical phases of flight.

Explanation of Relevant Service Information

    Dornier has issued Service Bulletin SB-328-24-062, Revision 1, 
dated June 27, 1995, which describes procedures for modification of the 
wiring that supplies power from the non-essential bus 2 to the bus 2 
avionics circuit, and from the non-essential bus 1 to the bus 1 
avionics circuit. This modification entails the rewiring of these 
circuits and the addition of certain electrical devices. This 
modification is intended to correct circuit logic and wiring design 
discrepancies that could cause these circuits to fail if the DC tie in 
the electrical system remains open during takeoff and landing. The LBA 
classified this service bulletin as mandatory and issued German 
airworthiness directive 95-284, dated August 4, 1995, 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 modification of the 
wiring that supplies power from the non-essential bus 2 to the bus 2 
avionics circuit, and from the non-essential bus 1 to the bus 1 
avionics circuit, by rewiring these circuits and adding electrical 
devices. The actions would be required to be accomplished in accordance 
with the service bulletin described previously.

Cost Impact

    The FAA estimates that 9 Dornier Model 328-100 series airplanes of 
U.S. registry would be affected by this proposed AD.
    It would take approximately 220 work hours per airplane to 
accomplish the proposed modification, at an average labor rate of $60 
per work hour. Required parts would be provided by the manufacturer at 
no cost to operators. Based on these figures, the cost impact of the 
proposed AD on U.S. operators is estimated to be $118,800, or $13,200 
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.

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: Docket 96-NM-114-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 
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) 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 failure, during takeoff and landing, of the No. 2 
primary flight and multiple function displays, or the autopilot/

[[Page 64494]]

 yaw damper servos, which consequently could result in the inability 
of the flight crew to respond to and control the systems associated 
with these avionics during these critical phases of flight, 
accomplish the following:
    (a) Within 6 months after the effective date of this AD, modify 
the wiring that supplies power from the non-essential bus 2 to the 
bus 2 avionics circuit, and from the non-essential bus 1 to the bus 
1 avionics circuit, in accordance with Dornier Service Bulletin SB-
328-24-062, Revision 1, dated June 27, 1995.
    (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 
Secs. 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 November 29, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-30967 Filed 12-4-96; 8:45 am]
BILLING CODE 4910-13-U