[Federal Register Volume 79, Number 88 (Wednesday, May 7, 2014)]
[Rules and Regulations]
[Pages 26111-26113]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-10392]



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-

[[Page 26112]]

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 
model airplane.
    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.

[[Page 26113]]

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 
of descent.
    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.
Earl Lawrence,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 2014-10392 Filed 5-6-14; 8:45 am]