[Federal Register Volume 79, Number 88 (Wednesday, May 7, 2014)]
[Rules and Regulations]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-10392]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 23
[Docket No. FAA-2014-0155; Notice No. 23-262-SC]
Special Conditions: Extra Flugzeugproduktions and Vertriebs
[Extra] GmbH, EA-300/LC; Acrobatic Category Aerodynamic Stability
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions.
SUMMARY: These special conditions are issued for the Extra EA-300/LC
airplane. This airplane will have a novel or unusual design feature(s)
associated with static stability. This airplane can perform at the
highest level of aerobatic competition. To be competitive, the aircraft
was designed with positive and, at some points, neutral stability
within its flight envelope. Its lateral and directional axes are also
decoupled from each other providing more precise maneuvering. The
applicable airworthiness regulations do not contain adequate or
appropriate safety standards for these design features. 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
to EA-300/LC airplanes certified solely in the acrobatic category.
DATES: These special conditions are May 7, 2014, and are applicable
beginning April 25, 2014.
FOR FURTHER INFORMATION CONTACT: Mr. Ross Schaller, Federal Aviation
Administration, Small Airplane Directorate, Aircraft Certification
Service, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone
(816) 329-4162; facsimile (816) 329-4090.
On February 3, 2011, Extra GmbH applied for an amendment to Type
Certificate No. A67EU to include the model number, EA-300/LC. The EA-
300/LC, which is a derivative of the EA-300/L, currently approved under
Type Certificate No. A67EU, is a single engine, two-place tandem canopy
cockpit, low wing aerobatic monoplane with conventional landing gear.
Its maximum takeoff weight is 2095 pounds (950 kilograms).
VNE is 219 knots, VNO is 138 knots, and
VA is 154 knots, indicated airspeed. Maximum altitude is
10,000 feet. The engine is a Lycoming AEIO-580-B1A with a rated power
of 315 Horsepower (Hp) at 2,700 revolutions per minute (rpm). The
airplane is proposed to be approved for Day-VFR operations with no
icing approval. The EA-300/LC is certified under European Aviation
Safety Agency (EASA) authority (Type Certificate Data Sheet EASA.A.362)
as a dual category (normal/acrobatic) airplane.
Acrobatic airplanes previously type certificated by the FAA did
comply with the stability provisions of part 23, subpart B. However,
airplanes like the EA-300/LC are considered as ``unlimited'' acrobatic
aircraft because they can perform at the highest level of aerobatic
competition and can perform any maneuvers listed in the Aresti Catalog.
The evolution of the ``unlimited'' types of acrobatic airplanes with
very low mass, exceptional roll rates, and very high G capabilities, in
addition to power to mass ratios that are unique to this type of
airplane, have led to airplanes that cannot comply with the regulatory
stability requirements. These airplanes can still be type-certificated,
but in the acrobatic category only and with special conditions and
The FAA will only consider certifying the EA-300/LC in the
acrobatic category. Extra GmbH will not be able to offer a normal
category-operating envelope to accommodate the increased fuel load
designed for cross-country operations. The FAA does recognize that fuel
exhaustion is one of the top accident causes associated with this class
of aircraft. For this reason, the FAA proposes to allow Extra to seek
certification of a limited acrobatic envelope at a higher weight that
will still meet the minimum load requirements of +6/-3 g associated
with Sec. 23.337. The EA-300/LC airplane would be approved for
unlimited maneuvers at or below its designed unlimited acrobatic
weight. The airplane would also be approved, at some higher weight (for
fuel/passenger), that would still meet the requirements of Sec. 23.337
for acrobatic category and may have restrictions on the maneuvers
Type Certification Basis
Under the provisions of 14 CFR 21.101, Extra GmbH must show that
the EA-300/LC meets the applicable provisions of part 23, as amended by
Amendment 23-34 effective September 14, 1987 and Special Condition 23-
ACE-65, published in the Federal Register (57 FR 175), September 9,
1992. These regulations will be incorporated into Type Certificate No.
A67EU after type certification approval of the EA-300/LC. The
regulations incorporated by reference in the type certificate are
commonly referred to as the ``original type certification basis.'' The
regulations incorporated by reference in A67EU are as follows:
14 CFR part 36, effective December 1, 1969, as amended by
Amendments 36-1 through 36-28.
Not approved for ditching; compliance with provisions for ditching
equipment in accordance with 14 FR 23.1415(a)(b) has not been
Approved for VFR-day only. Flight in known icing prohibited.
In addition, the certification basis includes other regulations,
special conditions and exemptions that are not relevant to these
special conditions. Type Certificate No. A67EU will be updated to
include a complete description of the certification basis for this
If the Administrator finds that the applicable airworthiness
regulations (i.e., 14 CFR part 23) do not contain adequate or
appropriate safety standards for the EA-300/LC because of a novel or
unusual design feature, special conditions are prescribed under the
provisions of Sec. 21.16.
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 or similar
novel or unusual design feature, or should any other model already
included on the same type certificate be modified to incorporate the
same or similar novel or unusual design feature, the special conditions
would also apply to the other model under Sec. 21.101.
In addition to the applicable airworthiness regulations and special
conditions, the EA-300/LC must comply with the fuel vent and exhaust
emission requirements of 14 CFR part 34 and the noise certification
requirements of 14 CFR part 36.
The FAA issues special conditions, as defined in 14 CFR 11.19, in
accordance with Sec. 11.38, and they become part of the type-
certification basis under Sec. 21.101.
Novel or Unusual Design Features
The Extra GmbH EA-300/LC will incorporate the following novel or
unusual design features:
For acrobatic category airplanes with unlimited acrobatic
capability: Neutral longitudinal and lateral static stability
The Code of Federal Regulations states static stability criteria
for longitudinal, lateral, and directional axes of an airplane.
However, none of these criteria is adequate to address the specific
issues raised in the flight characteristics of an unlimited aerobatic
airplane. Therefore, the FAA has determined after a flight-test
evaluation that, in addition to the requirements of parts 21 and 23,
special conditions are needed to address these static stability
Discussion of Comments
Notice of proposed special conditions No. 23-14-01-SC for the Extra
Flugzeugproduktions and Vertriebs (Extra) GmbH, EA-300/LC airplane was
published in the Federal Register on March 18, 2014 (79 FR 15062). No
comments were received, and the special conditions are adopted as
As discussed above, these special conditions are applicable to the
EA-300/LC. Should Extra GmbH apply at a later date for a change to the
type certificate to include another model incorporating the same novel
or unusual design feature, the special conditions would apply to that
model as well.
Under standard practice, the effective date of final special
conditions would be 30 days after the date of publication in the
Federal Register; however, as the certification date for the Extra GmbH
EA-300/LC is imminent, the FAA finds that good cause exists to make
these special conditions effective upon issuance.
This action affects only certain novel or unusual design features
on one model of airplanes. It is not a rule of general applicability.
List of Subjects in 14 CFR Part 23
Aircraft, Aviation safety, Signs and symbols.
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.
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 GmbH EA-300/LC airplanes.
1. Acrobatic Category Static Stability Requirements
SC23.171 Flight--General: Acrobatic category airplanes must be
neutrally or positively stable in the longitudinal, directional, and
lateral axes under Secs. SC23.173 through SC23.177. Additionally, the
airplane must show suitable stability and control ``feel'' (static
stability) in any condition normally encountered in service, if flight
tests show it is necessary for safe operation.
SC23.173 Static longitudinal stability: Under the conditions
specified in SC23.175 and with the airplane trimmed as indicated, the
characteristics of the elevator control forces, positions, and the
friction within the control system must be as follows:
(a) A pull on the yoke must be required to obtain and maintain
speeds below the specified trim speed and a push on the yoke required
to obtain and maintain speeds above the specified trim speed. This must
be shown at any speed that can be obtained, except that speeds
requiring a control force in excess of 40 pounds or speeds above the
maximum allowable speed or below the minimum speed for steady unstalled
flight need not be considered.
(b) The stick force or position must vary with speed so that any
substantial speed change results in a stick force or position clearly
perceptible to the pilot.
SC23.175 Demonstration of static longitudinal stability:
(a) Climb. The stick force curve must have, at a minimum, a
neutrally stable to stable slope at speeds between 85 and 115 percent
of the trim speed, with--
(1) Maximum continuous power; and
(2) The airplane trimmed at the speed used in determining the climb
performance required by Sec. 23.69(a).
(b) Cruise. With the airplane power and trim set for level flight
at representative cruising speeds at high and low altitudes, including
speeds up to VNO, except the speed need not exceed
(1) The stick force curve must, at a minimum, have a neutrally
stable to stable slope at all speeds within a range that is the greater
of 15 percent of the trim speed plus the resulting free return speed
range, or 40 knots plus the resulting free return speed range above and
below the trim speed, except the slope need not be stable--
(i) At speeds less than 1.3 VS1; or
(ii) For airplanes with VNE established under Sec.
23.1505(a), at speeds greater than VNE.
(c) Landing. The stick force curve must, at a minimum, have a
neutrally stable to stable slope at speeds between 1.1 VS1
and 1.8 VS1 with--
(1) Landing gear extended; and
(2) The airplane trimmed at--
(i) VREF, or the minimum trim speed if higher, with
power off; and
(ii) VREF with enough power to maintain a 3-degree angle
SC23.177 Static directional and lateral stability:
(a) The static directional stability, as shown by the tendency to
recover from a wings level sideslip with the rudder free, must be
positive for any landing gear and flap position appropriate to the
takeoff, climb, cruise, approach, and landing configurations. This must
be shown with symmetrical power up to maximum continuous power, and at
speeds from 1.2 VS1 up to the maximum allowable speed for
the condition being investigated. The angle of sideslip for these tests
must be appropriate for the airplane type. At larger angles of
sideslip, up to where full rudder is used or a control force limit in
Sec. 23.143 is reached, whichever occurs first, and at speeds from 1.2
VS1 to VO, the rudder pedal force must not
(b) In straight, steady slips at 1.2 VS1 for any landing
gear and flap positions, and for any symmetrical power conditions up to
50 percent of maximum continuous power, the rudder control movements
and forces must increase steadily, but not necessarily in constant
proportion, as the angle of sideslip is increased up to the maximum
appropriate to the type of airplane. The aileron control movements and
forces may increase steadily, but not necessarily in constant
proportion, as the angle of sideslip is increased up to the maximum
appropriate for the airplane type. At larger slip angles, up to the
angle at which the full rudder or aileron control is used or a control
force limit contained in Sec. 23.143 is reached, the aileron and
rudder control movements and forces must not reverse as the angle of
sideslip is increased. Rapid entry into, and recovery from, a maximum
sideslip considered appropriate for the airplane must not result in
uncontrollable flight characteristics.
Issued in Kansas City, Missouri, on April 25, 2014.
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 2014-10392 Filed 5-6-14; 8:45 am]
BILLING CODE 4910-13-P