[Federal Register Volume 62, Number 224 (Thursday, November 20, 1997)]
[Proposed Rules]
[Pages 61926-61927]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-30496]


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 Proposed Rules
                                                 Federal Register
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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  Federal Register / Vol. 62, No. 224 / Thursday, November 20, 1997 / 
Proposed Rules  

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. 143CE, Notice No. SC-23-ACE-93]


Special Conditions; EXTRA Flugzeugbau GmbH EA-400 Airplane Design

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of Proposed Special Conditions.

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SUMMARY: This document proposes special conditions for the EXTRA 
Flugzeugbau GmbH EA-400 airplane design. These designs will have novel 
and unusual design features when compared to the state of technology 
anticipated in the applicable airworthiness standards. These design 
features include performance characteristics for which the applicable 
regulations do not contain adequate or appropriate airworthiness 
standards. This document contains the additional airworthiness 
standards that the Administrator considers necessary to establish a 
level of safety equivalent to that provided by the current 
airworthiness standards.

DATES: Comments must be received on or before December 22, 1997.

ADDRESSES: Comments on this proposal may be mailed in duplicate to: 
Federal Aviation Administration, Regional Counsel, ACE-7, Attention: 
Rules Docket Clerk, Docket No. 143CE, Room 1558, 601 East 12th Street, 
Kansas City, Missouri 64106. All comments must be marked: Docket No. 
143CE. Comments may be inspected weekdays, except Federal holidays, 
between 7:30 a.m. and 4:00 p.m., at the Rules Docket location.

FOR FURTHER INFORMATION CONTACT: Kenneth W. Payauys, Aerospace 
Engineer, Standards Office (ACE-110), Small Airplane Directorate, 
Aircraft Certification Service, Federal Aviation Administration, 601 
East 12th Street, Kansas City, Missouri 64106; telephone (816) 426-
5688.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of 
these special conditions by submitting written data, views, or 
arguments. Communications should identify the regulatory docket or 
notice number and be submitted in duplicate to the address given above. 
All communications received on or before the closing date for comments 
given above will be considered by the Administrator before taking 
further rulemaking action on this proposal. Commenters wishing the FAA 
to acknowledge receipt of their comments submitted in response to this 
notice must include a self-addressed, stamped postcard on which the 
following statement is made: ``Comments to Docket No. 143CE.'' The 
postcard will be date stamped and returned to the addressee. The 
proposals contained in this notice may be changed in light of the 
comments received. All comments received will be available for 
examination by interested parties, both before and after the closing 
date for comments, at the Rules Docket. A report summarizing each 
substantive public contact with FAA personnel concerned with this 
rulemaking will be filed in the docket.

Background

    On April 6, 1993, the EXTRA Flugzeugbau GmbH, Schwarze Heide 21, D-
46569 Hunxe, Germany, made application for normal category type 
certification of the Model EA-400 airplane design. The EA-400 design is 
a two-place (side-by-side), all composite material, cantilevered high-
wing, retractable gear, unpressurized, single reciprocating engine, 
airplane with a maximum design weight of 3,974 pounds (1800 kilograms). 
It is intended for 14 CFR Part 91 operation as a day-VFR normal 
category airplane.

Type Certification Basis

    The type certification basis of the EXTRA Flugzeugbau GmbH EA-400 
airplane design is the following: 14 CFR Part 23, effective February 1, 
1965, through amendment 23-45, effective August 6, 1993; 14 CFR Part 
36, effective December 1, 1969, through amendment 36-21 effective 
December 28, 1995; exemptions, if any; equivalent level of safety 
findings, if any; and the special conditions adopted by this rulemaking 
action.

Discussion

    Special conditions may be issued and amended, as necessary, as part 
of the type certification basis if the Administrator finds that the 
airworthiness standards designated under 14 CFR Part 21, 
Sec. 21.17(a)(1) do not contain adequate or appropriate safety 
standards because of novel or unusual design features of an airplane. 
Special conditions, as appropriate, are issued under 14 CFR Part 11, 
Sec. 11.49 after public notice, as required by Secs. 11.28 and 11.29, 
and become a part of the type certification basis, as provided by 14 
CFR Part 21, Sec. 21.17(a)(2).
    The proposed type design of the EXTRA Flugzeugbau GmbH EA-400 
airplane incorporates certain novel and unusual design features for 
which the airworthiness regulations do not contain adequate or 
appropriate safety standards. These features include certain 
performance characteristics necessary for this type of airplane design 
that were not foreseen by the existing regulations.
    This special condition addresses the flight safety of the EA-400 in 
case of an engine compartment fire with resulting heat conduction 
through the engine-mounts to composite structure joints beyond the 
firewall. The type certificate applicant shall demonstrate that the 
airplane structure design, especially the engine-mount attachments to 
the structure beyond the firewall, is able to retain the engine while 
withstanding the following:
    1. An engine compartment fire, the loss of the most highly loaded 
composite joint, and heating of the next most highly loaded composite 
joint from those that remain;
    2. Maximum continuous power for 5 minutes; and
    3. Combined airplane flight maneuver and gust limit loads for at 
least 15 minutes.

    Note: The engine-mount attachments at the firewall are not the 
same as the engine-to-engine-mount attachments, which contain 
vibration dampers.

List of Subjects in 14 CFR Part 23

    Aircraft, Aviation safety, Signs and symbols.

[[Page 61927]]

Citation

    The authority citation for these special conditions is as follows:

    Authority: 49 U.S.C. 106(g); 40113, 44701, 44702, and 44704; 14 
CFR 21.16 and 21.17; and 14 CFR 11.28 and 11.29(b).

The Proposed Special Conditions

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes the 
following special conditions as part of the type certification basis 
for the EXTRA Flugzeugbau GmbH EA-400 airplane design.

Heat Capability of Engine Mount and Fuselage Connection Joint

    (a) Modify the airworthiness standards given in 14 CFR part 23, 
POWERPLANT FIRE PROTECTION, Nacelle areas behind firewalls 
(Sec. 23.1182), by making the most critical composite engine-mount 
attachment ineffective (assumed destroyed by heat). Then, for 15 
minutes, apply an additional flame test of 500 deg.C (932 deg.F) to the 
next most structurally critical engine-mount of those remaining. The 
flame shall encompass the whole engine-mount structural attach fitting. 
Conductive heat will affect the metallic and composite joint structural 
capability beyond the firewall. Test the joint structural capability 
with these simultaneous limit load conditions (under these conditions, 
the engine shall remain attached to the airplane):
    (1) The combined thrust, torque and gyroscopic loads resulting from 
the engine and propeller at maximum continuous power for the first 5 
minutes, and
    (2) The airplane normal inertial limit loads that result from the 
following:
    (i) A maneuver load factor equal to that obtained from a constant 
altitude 30 deg. bank, combined with
    (ii) The positive and negative vertical design gust load factors 
that occur at the design maneuvering speed and the minimum flying 
weight, and
    (iii) A factor-of-safety equal to one.

    Issued in Kansas City, Missouri on November 6, 1997.
Mary Ellen A. Schutt,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-30496 Filed 11-19-97; 8:45 am]
BILLING CODE 4910-13-P