[Federal Register Volume 78, Number 160 (Monday, August 19, 2013)]
[Rules and Regulations]
[Pages 50313-50317]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-20151]



Federal Aviation Administration

14 CFR Part 21

Final Additional Airworthiness Design Standards: Night Visual 
Flight Rules (VFR) Under the Special Class (JAR-VLA) Regulations; 
AQUILA Aviation by Excellence GmbH, Model AT01

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Issuance of airworthiness design standards.


SUMMARY: This document is an issuance of Final Airworthiness design 
criteria for night visual flight rules (VFR) expansion and 
substantiation for the

[[Page 50314]]

Aquila GmbH AT01. These additional provisions are expansions of the 
existing JAR-VLA (Joint Aviation Requirements--Very Light Aircraft) and 
CS-VLA regulations to include Night-VFR. The current regulations only 
allow Day-VFR, but the European Aviation Safety Agency (EASA) is 
expanding the VLA regulations for this type of airplane through EASA 
special conditions. These FAA design criteria are being proposed to be 
the same as the EASA Special Conditions. The original certification of 
the aircraft was done under the provisions of 14 CFR part 21, Sec.  
21.29, as a 14 CFR part 21, Sec.  21.17(b), special class aircraft, 
JAR-VLA, using the requirements of JAR-VLA Amendment VLA/92/01 as 
developed by the Joint Aviation Authority, and under Title 14 of the 
Code of Federal Regulations and two additional design criteria issued 
on September 2, 2003 (68 FR 56809).

DATES: Effective September 18, 2013.

FOR FURTHER INFORMATION CONTACT: Mr. Doug Rudolph, Aerospace Engineer, 
Standards Office (ACE-112), Small Airplane Directorate, Aircraft 
Certification Service, FAA; telephone number (816) 329-4059, fax number 
(816) 329-4090, email at [email protected].

SUPPLEMENTARY INFORMATION: Any person may obtain a copy of this 
information by contacting the person named above under FOR FURTHER 


    The regulation applicable to the Amended Type Certificate (TC) 
Night-VFR approval is Sec.  21.17(b). This section describes the 
regulatory basis for the approval of JAR-VLA and CS-VLA aircraft as a 
special class. Policy on this subject includes AC 23-11B and AC 21.17-
    Airworthiness rules that are applicable to this Night-VFR approval 
are Sec. Sec.  23.1381 through 23.1397 and 23.1401.
    FAA policy expressed in ACs 23-11B and 21.17-3 limits JAR-VLA and 
CS-VLA aircraft approved under Sec.  21.17(b), to Day-VFR operations. 
Part 23 certification was required for Night-VFR approval because the 
VLA rules were not adequate to address Night-VFR operations. Since 
publishing these advisory circulars, EASA has developed special 
conditions to CS-VLA that are adequate to allow Night-VFR approvals. If 
the applicant complies with the applicable airworthiness rules in CS-
VLA and the EASA special conditions, the previous policy disallowing 
Night-VFR is no longer valid.
    Airplanes approved as special class under Sec.  21.17(b) may be 
type certificated as both Day-VFR and Night-VFR if the certification 
includes the required instrumentation and equipment specified in 14 CFR 
91.205, and the certification basis includes the applicable rules of 
CS-VLA at date of application and the appropriate EASA special 
    The FAA has concluded that it is acceptable to allow Night-VFR 
certification for the Aquila Model AT01 and future JAR-VLA (CS-VLA) 
models under the special class amended TC project AT00617CE-A. 
Revisions to ACs 23-11B and 21.17-3 will be made to allow this 
expansion to Night-VFR on other JAR-VLA (CS-VLA) airplanes.

Discussion of Comments

    Existence of proposed airworthiness standards for acceptance under 
14 CFR part 21, Sec.  21.17(b), special class aircraft, JAR-VLA; the 
AQUILA Model AT01 was published in the Federal Register on Friday May 
31, 2013, 78 FR 32576. No comments were received, and the airworthiness 
design standards are adopted.


    As discussed above, these airworthiness design standards under the 
special class, JAR-VLA rule are applicable to the Aquila AT01 model and 
future JAR-VLA (CS-VLA) models on FAA TCDS A51CE.


    This action affects only certain airworthiness design standards on 
Aquila AT01 model and future JAR-VLA model airplanes shown on FAA TCDS 
A51CE. It is not a standard of general applicability and it affects 
only the applicant who applied to the FAA for approval of these 
features on the airplane.


    The authority citation for these airworthiness standards is as 

    Authority:  49 U.S.C. 106(g), 40113 and 44701.

    To satisfy the additional required provisions of ``Proposed 
Airworthiness Design Standards: Night visual flight rules (VFR) Under 
the Special Class (JAR-VLA) Regulations of 14 CFR 21.17(b); AQUILA 
Aviation by Excellence GmbH, Model AT01'', the applicant, AQUILA, has 
submitted a request to the FAA to use the EASA Special Conditions as 
shown on EASA Certification Review Item (CRI) A-01 Issue 3, Appendix 1, 
dated October 3, 2010 ``EASA Special Condition Airworthiness standards 
for CS-VLA aeroplane to be operated under Night-VFR operations. 
Applicable to AQUILA AT01'' as follows:

Appendix 1

    Special Condition

Airworthiness Standards for CS-VLA Aeroplane To Be Operated Under 
Night-VFR Operations

Applicable to AQUILA AT01

    Instead of VLA 1, VLA 181, VLA 773, VLA 807, VLA 903, VLA 905, 
VLA 1121, VLA 1143, VLA 1147, VLA 1322, VLA 1325, VLA 1331, VLA 
1351, VLA 1353, VLA 1431, VLA 1547, VLA 1559, VLA 1583 and due to 
absence of specific requirements in CS-VLA (VLA 1107, VLA 1381, VLA 
1383) the following proposed Special Conditions have to be complied 

SpC VLA 1 Applicability

    This airworthiness code is applicable to aeroplanes with a 
single engine (spark- or compression-ignition) having not more than 
two seats, with a Maximum Certificated Take-off Weight of not more 
than 750 kg and a stalling speed in the landing configuration of not 
more than 83 km/h (45 knots) (CAS), to be approved for day-VFR or 
for day- and night VFR. (See AMC VLA 1.)

SpC VLA 181 Dynamic Stability

    (a) Any short period oscillation not including combined lateral-
directional oscillations occurring between the stalling speed and 
the maximum allowable speed appropriate to the configuration of the 
aeroplane must be `heavily damped with the primary controls--
    (1) Free; and
    (2) In a fixed position
    (b) Any combined lateral-directional oscillations (`Dutch roll') 
occurring between the stalling speed and the maximum allowable speed 
appropriate to the configuration of the aeroplane must be damped to 
1/10 amplitude in 7 cycles with the primary controls--
    (1) Free; and paragraph must be shown under the following
    (2) In a fixed position.
    (c) Any long period oscillation of the flight path (phugoid) 
must not be so unstable as to cause an unacceptable increase in 
pilot workload or otherwise endanger the aeroplane. When in the 
conditions of CS VLA 175, the longitudinal control force required to 
maintain speeds differing from the trimmed speed by at least plus or 
minus 15% is suddenly released; the response of the aeroplane must 
not exhibit any dangerous characteristics nor be excessive in 
relation to the magnitude of the control force released (see AMC VLA 

SpC VLA 773 Pilot Compartment View

    The pilot compartment must be free from glare and reflections 
that could interfere with the pilot's vision in all operations for 
which the certification is requested. The pilot compartment must be 
designed so that--
    (a) The pilot's view is sufficiently extensive, clear, and 
undistorted, for safe operation;

[[Page 50315]]

    (b) The pilot is protected from the elements so that moderate 
rain conditions do not unduly impair his view of the flight path in 
normal flight and while landing; and
    (c) Internal fogging of the windows covered under sub-paragraph 
(a) of this paragraph can be easily cleared by the pilot unless 
means are provided to prevent fogging. (See AMC VLA773.)

SpC VLA807 Emergency Exits

    (a) Where exits are provided to achieve compliance with CS-VLA 
783(a), the opening system must be designed for simple and easy 
operation. It must function rapidly and be designed so that it can 
be operated by each occupant strapped in his seat, and also from 
outside the cockpit. Reasonable provisions must be provided to 
prevent jamming by fuselage deformation.
    (b) Markings must be suitable for night VFR, if this kind of 
operation is requested. (See AMC VLA 807(b))

SpC VLA903 Engine

    (a) The engine must meet the specifications of CS-22 Subpart H 
for day-VFR operation, and must meet the Specification of CS-E for 
night-VFR operation.
    (b) Restart capability. An altitude and airspeed envelope must 
be established for the aeroplane for in-flight engine restarting and 
the installed engine must have a restart capability within that 

SpC VLA 905 Propeller

    (a) The propeller must meet the specifications of CS-22 Subpart 
J for day-VFR operation. For night-VFR operations the Propeller and 
the Control System must meet the Specification of CS-P except for 
fixed pitch propellers, for which CS-22 Subpart J is sufficient.
    (b) Engine power and propeller shaft rotational speed may not 
exceed the limits for which the propeller is certificated or 

SpC VLA 1107 Induction System Filters

    On reciprocating-engine installations, if an air filter is used 
to protect the engine against foreign material particles in the 
induction air supply--
    (a) Each air filter must be capable of withstanding the effects 
of temperature extremes, rain, fuel, oil, and solvents to which it 
is expected to be exposed in service and maintenance; and
    (b) Each air filter must have a design feature to prevent 
material separated from the filter media from re-entering the 
induction system and interfering with proper fuel metering 

SpC VLA 1121 Exhaust System: General

    (a) Each exhaust system must ensure safe disposal of exhaust 
gases without fire hazard or carbon monoxide contamination in the 
personnel compartment.
    (b) Each exhaust system part with a surface hot enough to ignite 
flammable fluids or vapours must be located or shielded so that 
leakage from any system carrying flammable fluids or vapours will 
not result in a fire caused by impingement of the fluids or vapours 
on any part of the exhaust system including shields for the exhaust 
    (c) Each exhaust system component must be separated by fireproof 
shields from adjacent flammable parts of the aeroplane that are 
outside the engine compartment.
    (d) No exhaust gases may discharge dangerously near any fuel or 
oil system drain.
    (e) No exhaust gases may be discharged where they will cause a 
glare seriously affecting the pilot's vision at night.
    (f) Each exhaust system component must be ventilated to prevent 
points of excessively high temperature.
    (g) Each exhaust heat exchanger must incorporate means to 
prevent blockage of the exhaust port after any internal heat 
exchanger failure.

SpC VLA 1143 Engine Controls

    (a) The power or supercharger control must give a positive and 
immediate responsive means of controlling its engine or 
    (b) If a power control incorporates a fuel shut-off feature, the 
control must have a means to prevent the inadvertent movement of the 
control into the shut-off position. The means must--
    (1) Have a positive lock or stop at the idle position; and
    (2) Require a separate and distinct operation to place the 
control in the shut-off position.
    (c) For reciprocating single-engine aeroplanes, each power or 
thrust control must be designed so that if the control separates at 
the engine fuel metering device, the aeroplane is capable of 
continuing safe flight and landing. (See AMC VLA 1143(c)).

SpC VLA 1147 Mixture Control

    (a) The Control must require a separate and distinct operation 
to move the control toward lean or shut-off position.
    (b) Each manual engine mixture control must be designed so that, 
if the control separates at the engine fuel metering device, the 
aeroplane is capable of continuing safe flight and landing. (See AMC 
VLA 1147(b)).

SpC VLA 1322 Warning, Caution, and Advisory Lights

    If warning, caution, or advisory lights are installed in the 
cockpit, they must be--
    (a) Red, for warning lights (lights indicating a hazard which 
may require immediate corrective action);
    (b) Amber, for caution lights (lights indicating the possible 
need for future corrective action);
    (c) Green, for safe operation lights; and
    (d) Any other colour, including white, for lights not described 
in sub-paragraphs (a) to (c) of this paragraph, provided the colour 
differs sufficiently from the colours prescribed in subparagraphs 
(a) to (c) of this paragraph to avoid possible confusion.
    (e) Effective under all probable cockpit lighting conditions.

SpC VLA 1325 Static Pressure System

    (a) Each instrument provided with static pressure case 
connections must be so vented that the influence of aeroplane speed, 
the opening and closing of windows, moisture or other foreign 
matter, will not significantly affect the accuracy of the 
    (b) The design and installation of a static pressure system must 
be such that--
    (1) Positive drainage of moisture is provided;
    (2) Chafing of the tubing, and excessive distortion or 
restriction at bends in the tubing, is avoided; and
    (3) The materials used are durable, suitable for the purpose 
intended, and protected against corrosion.
    (c) Each static pressure system must be calibrated in flight to 
determine the system error. The system error, in indicated pressure 
altitude, at sea-level, with a standard atmosphere, excluding 
instrument calibration error, may not exceed 9 m (30 ft) per 185 km/h (100 knot) speed for the appropriate 
configuration in the speed range between 1[middot]3 VSO 
with flaps extended and 1[middot]8 VS1 with flaps 
retracted. However, the error need not be less than 9 m 
(30 ft).

SpC VLA 1331 Instruments Using a Power Supply

    For each aeroplane--
    (a) Each gyroscopic instrument must derive its energy from power 
sources adequate to maintain its required accuracy at any speed 
above the best rate-of-climb speed;
    (b) Each gyroscopic instrument must be installed so as to 
prevent malfunction due to rain, oil and other detrimental elements; 
    (c) There must be a means to indicate the adequacy of the power 
being supplied to the instruments.
    (d) For night VFR operation there must be at least two 
independent sources of power and a manual or an automatic means to 
select each power source for each instrument that uses a power 

SpC VLA 1351 Electrical Systems and Equipment: General

    (a) Electrical system capacity. Each electrical system must be 
adequate for the intended use. In addition--
    (1) Electric power sources, their transmission cables, and their 
associated control and protective devices, must be able to furnish 
the required power at the proper voltage to each load circuit 
essential for safe operation; and
    (2) Compliance with sub-paragraph (a)(l) of this paragraph must 
be shown by an electrical load analysis, or by electrical 
measurements, that account for the electrical loads applied to the 
electrical system in probable combinations and for probable 
    (b) Functions. For each electrical system, the following apply:
    (1) Each system, when installed, must be--
    (i) Free from hazards in itself, in its method of operation, and 
in its effects on other parts of the aeroplane;
    (ii) Protected from fuel, oil, water, other detrimental 
substances, and mechanical damage; and
    (iii) So designed that the risk of electrical shock to occupants 
and ground personnel is reduced to a minimum.
    (2) Electric power sources must function properly when connected 
in combination or independently.
    (3) No failure or malfunction of any electric power source may 
impair the ability of any

[[Page 50316]]

remaining source to supply load circuits essential for safe 
    (4) Each electric power source control must allow the 
independent operation of each source, except that controls 
associated with alternators that depend on a battery for initial 
excitation or for stabilisation need not break the connection 
between the alternator and its battery.
    (c) Generating system. There must be at least one generator if 
the electrical system supplies power to load circuits essential for 
safe operation. In addition--
    (1) Each generator must be able to deliver its continuous rated 
    (2) Generator voltage control equipment must be able to 
dependably regulate the generator output within rated limits;
    (3) Each generator must have a reverse current cut out designed 
to disconnect the generator from the battery and from the other 
generators when enough reverse current exists to damage that 
    (4) There must be a means to give immediate warning to the pilot 
of a failure of any generator; and
    (5) Each generator must have an overvoltage control designed and 
installed to prevent damage to the electrical system, or to 
equipment supplied by the electrical system, that could result if 
that generator were to develop an overvoltage condition.
    (d) Instruments. There must be a means to indicate to the pilot 
that the electrical power supplies are adequate for safe operation. 
For direct current systems, an ammeter in the battery feeder may be 
    (e) Fire resistance. Electrical equipment must be so designed 
and installed that in the event of a fire in the engine compartment, 
during which the surface of the firewall adjacent to the fire is 
heated to 1100 [deg]C for 5 minutes or to a lesser temperature 
substantiated by the applicant, the equipment essential to continued 
safe operation and located behind the firewall will function 
satisfactorily and will not create an additional fire hazard. This 
may be shown by test or analysis.
    (f) External power. If provisions are made for connecting 
external power to the aeroplane, and that external power can be 
electrically connected to equipment other than that used for engine 
starting, means must be provided to ensure that no external power 
supply having a reverse polarity, or a reverse phase sequence, can 
supply power to the aeroplane's electrical system. The location must 
allow such provisions to be capable of being operated without hazard 
to the aeroplane or persons.

SpC VLA 1353 Storage Battery Design and Installation

    (a) Each storage battery must be designed and installed as 
prescribed in this paragraph.
    (b) Safe cell temperatures and pressures must be maintained 
during any probable charging and discharging condition. No 
uncontrolled increase in cell temperature may result when the 
battery is recharged (after previous complete discharge)--
    (1) At maximum regulated voltage or power;
    (2) During a flight of maximum duration; and
    (3) Under the most adverse cooling condition likely to occur in 
    (c) Compliance with sub-paragraph (b) of this paragraph must be 
shown by tests unless experience with similar batteries and 
installations has shown that maintaining safe cell temperatures and 
pressures presents no problem.
    (d) No explosive or toxic gases emitted by any battery in normal 
operation, or as the result of any probable malfunction in the 
charging system or battery installation, may accumulate in hazardous 
quantities within the aeroplane.
    (e) No corrosive fluids or gases that may escape from the 
battery may damage surrounding structures or adjacent essential 
    (f) Each nickel cadmium battery installation capable of being 
used to start an engine or auxiliary power unit must have provisions 
to prevent any hazardous effect on structure or essential systems 
that may be caused by the maximum amount of heat the battery can 
generate during a short circuit of the battery or of its individual 
    (g) Nickel cadmium battery installations capable of being used 
to start an engine or auxiliary power unit must have--
    (1) A system to control the charging rate of the battery 
automatically so as to prevent battery overheating;
    (2) A battery temperature sensing and over-temperature warning 
system with a means for disconnecting the battery from its charging 
source in the event of an over-temperature condition; or
    (3) A battery failure sensing and warning system with a means 
for disconnecting the battery from its charging source in the event 
of battery failure.
    (h) In the event of a complete loss of the primary electrical 
power generating system, the battery must be capable of providing 30 
minutes of electrical power to those loads that are essential to 
continued safe flight and landing. The 30-minute time period 
includes the time needed for the pilot(s) to recognize the loss of 
generated power, and to take appropriate load shedding action.

SpC VLA 1381 Instrument Lights

    The instrument lights must--
    (a) Make each instrument and control easily readable and 
    (b) Be installed so that their direct rays, and rays reflected 
from the windshield or other surface, are shielded from the pilot's 
eyes; and
    (c) Have enough distance or insulating material between current 
carrying parts and the housing so that vibration in flight will not 
cause shorting. A cabin dome light is not an instrument light.

SpC VLA 1383 Taxi and Landing Lights

    Each taxi and landing light must be designed and installed so 
    (a) No dangerous glare is visible to the pilots;
    (b) The pilot is not seriously affected by halation;
    (c) It provides enough light for night operations; and
    (d) It does not cause a fire hazard in any configuration.

SpC VLA 1431 Electronic Equipment

    Electronic equipment and installations must be free from hazards 
in themselves, in their method of operation, and in their effects on 
other components. For operations for which electronic equipment is 
required, compliance must be shown against CS-VLA 1309.

SpC VLA 1547 Magnetic Direction Indicator

    (a) A placard meeting the requirements of this section must be 
installed on or near the magnetic direction indicator.
    (b) The placard must show the calibration of the instrument in 
level flight with the engine operating.
    (c) The placard must state whether the calibration was made with 
radio receivers on or off.
    (d) Each calibration reading must be in terms of magnetic 
headings in not more than 30[deg] increments.
    (e) If a magnetic non-stabilized direction indicator can have a 
deviation of more than 10[deg] caused by the operation of electrical 
equipment, the placard must state which electrical loads, or 
combination of loads, would cause a deviation of more than 10[deg] 
when turned on.

SpC VLA 1559 Operating Limitations Placards

    The following placards must be plainly visible to the pilot:
    (a) A placard stating the following airspeeds (IAS):
    (1) Design manoeuvring speed, VA;
    (2) The maximum landing gear operating speed, VLO.
    (b) A placard stating `This aeroplane is classified as a very 
light aeroplane approved for day VFR only or day and night VFR, 
whichever is applicable, in non-icing conditions. All aerobatic 
manoeuvres including intentional spinning are prohibited. See Flight 
Manual for other limitations'.

SpC VLA 1583 Operating Limitations

    (a) Airspeed limitations. The following information must be 
    (1) Information necessary for the marking of the airspeed limits 
on the indicator, as required in CS-VLA 1545 and the significance of 
the colour coding used on the indicator.
    (2) The speeds VA, VLo, VLE where appropriate.
    (b) Weights. The following information must be furnished:
    (1) The maximum weight.
    (2) Any other weight limits, if necessary.
    (c) Centre of gravity. The established c.g. limits required by 
CS-VLA 23 must be furnished.
    (d) Manoeuvres. Authorised manoeuvres established in accordance 
with CS-VLA 3.
    (e) Flight load factors. Manoeuvring load factors: The following 
must be furnished:
    (1) The factors corresponding to point A and point C of figure 1 
of CS-VLA 333(b), stated to be applicable at VA.
    (2) The factors corresponding to point D and point E of figure 1 
of CS-VLA 333(b) to be applicable at VNE.

[[Page 50317]]

    (3) The factor with wing flaps extended as specified in CS-VLA 
    (f) Kinds of operation. The kinds of operation (day VFR or day 
and night VFR, whichever is applicable) in which the aeroplane may 
be used, must be stated. The minimum equipment required for the 
operation must be listed.
    (g) Powerplant limitations. The following information must be 
    (1) Limitation required by CS-VLA 1521.
    (2) Information necessary for marking the instruments required 
by CS-VLA 1549 to 1553.
    (3) Fuel and oil designation.
    (4) For two-stroke engines, fuel/oil ratio.
    (h) Placards. Placards required by CS-VLA 1555 to 1561 must be 

    Issued in Kansas City, Missouri, on August 12, 2013.
Earl Lawrence,
Manager, Small Airplane Directorate, Aircraft Certification Service.

[FR Doc. 2013-20151 Filed 8-16-13; 8:45 am]