Aircraft Features

Information about Aircraft01_popis

Viper SD4 is an aerodynamically controlled, single-engine, two-seater, low-wing all-metal aircraft with the side-by-side configuration of the seats.


The aircraft’s fuselage is made as an all-metal semi-monocoque and frame structure, comprising stringers and an aluminum alloy skin; the vertical stabilizer is an integral part of the fuselage. The engine compartment is separated from the crew compartment by a steel firewall.


It is all-metal, of a rectangular planform and a single-spar design, with an auxiliary spar. The wing is equipped with ailerons, slotted flaps, controlled electrically into four positions, and integral fuel tanks. The wing tips are equipped with composite wingtip devices.



It is of a classic configuration. The horizontal stabilizing surface is made of a continual stabilizer with the right and left parts of the elevator interconnected by the control transmission. The elevator is equipped with a trimming tab, controlled electrically. The vertical stabilizing surface of a trapeze shape consists of a vertical stabilizer and a rudder.


It is designed with the seats configured side by side. The cockpit is covered by a clear or tinted canopy, ensuring a very good outlook. The canopy opens up and backward. The locking of the canopy is a two point one, controlled by two independent levers on the inner sides of the canopy, allowing its locking by a key. The cockpit is equipped with three air vents, located on the sides of the fuselage and it is ventilated by the ram air, led above and to the sides of the instrument panel, with the possibility to control the through-flow. The crew will appreciate the heating of the cockpit, in particular in wintertime.

Landing gear06-podvozok

It is tricycle with a front wheel. The main landing gear comprises composite springs; the wheels of the main landing gear are braked by hydraulic disk brakes. The brakes are controlled centrally by a lever located on the central panel, between the pilots’ seats. The front landing gear is cushioned by a rubber band. The front landing gear wheel is steerable. The wheels of the landing gear are equipped with streamline covers.



It is doubled in a classic configuration. The elevator and the ailerons are controlled via push-pull rods and the rudder is controlled via Bowden cables.


Viper SD4 is supplied with a three-point harness.

Fuel system

The fuel system comprises two lockable integrated tanks in the wings, equipped with fuel gauge floats and a drain valve, fuel piping, the main fuel valve, a fuel filter, and an electric priming pump.



The aircraft is powered by the Rotax 912 ULS/S - a four-stroke, horizontally opposed four-cylinder engine with liquid-cooled cylinder heads and air-cooled cylinders. The engine is equipped with a reduction gear and two carburetors.


Both a fix-pitch and variable-pitch propellers can be used on the plane. The supplied propeller is selected and adjusted for a specific version of the engine and the intended use of the aircraft, so that ensures its maximum performance within the allowed RPM range in all operation modes.

Tow hook08_vlecne

Viper SD4 can be equipped with an optional tow hook for towing gliders with a take-off weight of up to 750 kg.