[Federal Register Volume 61, Number 166 (Monday, August 26, 1996)]
[Proposed Rules]
[Pages 43689-43690]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-21596]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-232-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 replacement of certain 
hydraulic fuses of the landing gear with improved fuses. This proposal 
is prompted by results of extended testing, which revealed that the 
hydraulic fuses of the landing gear failed to operate due to movement 
of the end of the spring within the fuses over the end of the flange of 
the spool. The actions specified by the proposed AD are intended to 
prevent such failure, which could result in external leakage in the 
brake lines downstream of the respective fuse and consequent loss of 
hydraulic fluid; this condition, if not corrected, could result in 
partial loss of the main hydraulic power supply.

DATES: Comments must be received by October 4, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-232-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 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-232-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-232-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 328-100 series airplanes. The LBA advises 
that, during extended testing of this airplane model, the hydraulic 
fuses of the landing gear failed to operate due to movement of the end 
of the spring within the fuses over the end of the flange of the spool. 
If a hydraulic fuse fails to operate, external leakage could occur in 
the brake lines downstream of the respective fuse and loss of hydraulic 
fluid could occur. This condition, if not corrected, could result in 
partial loss of the main hydraulic power supply.

Explanation of Relevant Service Information

    Dornier has issued Service Bulletin SB-328-32-048, dated August 11, 
1994, which describes procedures for replacement of certain hydraulic 
fuses of the landing gear with fuses having an improved design. The LBA 
classified

[[Page 43690]]

this service bulletin as mandatory and issued German airworthiness 
directive 95-051, dated February 3, 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, the 
proposed AD would require replacement of certain hydraulic fuses of the 
landing gear with fuses having an improved design. The actions would be 
required to be accomplished in accordance with the service bulletin 
described previously.

Explanation of Proposed Compliance Time

    Operators should note that, although the Dornier Service Bulletin 
SB-328-25-072 recommends accomplishment of the described procedures 
within 45 days, this AD would require accomplishment of the actions 
within 90 days. Based upon an analysis of the unsafe condition, the FAA 
finds that a compliance time of 90 days will address the unsafe 
condition in a timely manner. In developing an appropriate compliance 
time for this AD, the FAA considered not only the safety implications 
and the degree of urgency associated with addressing the subject unsafe 
condition, but the maximum interval of time allowable for all affected 
airplanes to continue to operate without compromising safety. The FAA 
finds 90 days to be an appropriate compliance time for accomplishing 
these actions.

Cost Impact

    The FAA estimates that 5 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 2 work 
hours per airplane to accomplish the proposed actions, and that the 
average labor rate is $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 $600, or $120 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.


39.13  [Amended]

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

Dornier: Docket 95-NM-232-AD

    Applicability: Model 328-100 series airplanes; serial numbers 
3005 through 3008 inclusive, 3010, 3011, and 3012; 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 (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 partial loss of the main hydraulic power supply due 
to loss of hydraulic fluid, accomplish the following:
    (a) Within 90 days after the effective date of this AD, replace 
landing gear hydraulic fuses having part number ACM30488, MOD states 
2 through 6, with MOD 7 fuses in accordance with Dornier Service 
Bulletin SB-328-32-048, dated August 11, 1994.
    (b) As of the effective date of this AD, no person shall install 
a landing gear hydraulic fuse having part number ACM30488, MOD 
states 2 through 6, on any airplane.
    (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, 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.

    (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. Issued in Renton, 
Washington, on August 19, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-21596 Filed 8-23-96; 8:45 am]
BILLING CODE 4910-13-U