[Federal Register Volume 63, Number 20 (Friday, January 30, 1998)]
[Rules and Regulations]
[Pages 4563-4564]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-2399]
[[Page 4563]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 23
[Docket No. 143CE; Special Conditions No. SC-23-ACE-93]
Special Conditions: EXTRA Flugzeugbau GmbH, Model EA-400; Heat
Capability of the Engine Mount and the Fuselage Connection Joint
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions.
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SUMMARY: These special conditions are issued for the EXTRA Flugzeugbau
GmbH, Model EA-400 airplane. This airplane will have a novel or unusual
design feature associated with the Heat Capability of the Engine Mount
and the Fuselage Connection Joint. The applicable airworthiness
regulations do not contain adequate or appropriate safety standards for
this design feature. These special conditions contain the additional
safety standards that the Administrator considers necessary to
establish a level of safety equivalent to that established by the
existing airworthiness standards.
EFFECTIVE DATE: March 2, 1998.
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:
Background
On April 6, 1993, EXTRA Flugzeugbau GmbH applied for a type
certificate for their new Model EA-400. 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.
The proposed type design of the EXTRA Flugzeugbau GmbH Model EA-400
airplane incorporates certain novel and unusual design features for
which the exiting 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.
Type Certification Basis
Under the provisions of 14 CFR part 21, Sec. 21.17, EXTRA
Flugzeugbau GmbH must show that the Model EA-400 meets the applicable
provisions of 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.
Special conditions are issued, as appropriate, under 14 CFR part 11
Sec. 11.49 after public notice, as required by Sec. 11.28 and
Sec. 11.29(b), and become part of the type certification basis in
accordance with 14 CFR part 21, Sec. 21.17(a)(2)).
Special conditions are initially applicable to the model for which
they are issued. Should the type certificate for that model be amended
later to include any other model that incorporates the same novel or
unusual design feature, the special conditions would also apply to the
other model under the provisions of 14 CFR part 21, Sec. 21.101(a)(1)).
Novel or Unusual Design Features
The Model EA-400 will incorporate the following novel or unusual
design features: Heat Capability of the Engine Mount and the Fuselage
Connection Joint.
Discussion of Comments
Notice of proposed special conditions No. SC-23-ACE-93 for the
EXTRA Flugzeugbau GmbH EA-400 airplanes was published on November 20,
1997 (62 FR 61926). No comments were received and the special
conditions are adopted as proposed.
Applicability
As discussed above, these special conditions are applicable to the
Model A-400. Should EXTRA Flugzeugbau GmbH apply at a later date for a
change to the type certificate to include another model incorporating
the same level or unusual design feature, the special conditions would
apply to that model as well under the provisions of Sec. 21.101(a)(1).
Conclusion
This action affects only certain novel or unusual design features
on one model of airplane. It is not a rule of general applicability,
and it affects only the applicant who applied to the FAA for approval
of these features on the airplane.
List of Subjects in 14 CFR Part 23
Aircraft, Aviation safety, Signs and symbols.
Citation
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113 and 44701; 14 CFR 21.16 and
21.17; and 14 CFR 11.28 and 11.49.
The Special Conditions
Accordingly, pursuant to the authority delegated to me by the
Administrator, the following special conditions are issued as part of
the type certification basis for EXTRA Flugzeugbau GmbH Model EA-400
airplanes:
Heat Capability of the Engine Mount and the 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):
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(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 January 22, 1998.
Marvin Nuss,
Assistant Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-2399 Filed 1-29-98; 8:45 am]
BILLING CODE 4910-13-M