Airplane VAI-41


Four-seater turboprop amhibian


VAI 41 01


VAI-41 is the four-seater multipurpose amphibian airplane equipped with advanced turboprop engine PBS TP100.

The airplane is intended for amateur and business flights, for tutoring, air surveillance, tourism, etc.

The proposed amphibian airplane can get usage in lands with a many of lakes and rivers, and also in sea coastal areas in quiet sea.

The main advantages of this project is the high performances with a amphibious propertys combination.

VAI-41 Can perform take-off and landing from a water bodies at roughness up to 0,6 m (2 ft), and also from conventional runways, unpaved airfields.

The amphibian can go out water on coast and contrariwise in the availability of artificial hydrodescent or a coastal slope with suitable conditions.

Besides, the amphibian airplane in case of emergency landing has a wider range of choice both overland landing fields, and water bodies.

In this project some engineering solutions which give the chance to get optimum relationship of the performances, and on a number of parametres to receive high values.

Highly-aspect wing with a highly effective wing section, the smooth surface of all airplane, optimum geometry of the fuselage and the tail unit, allow to have small aerodynamic drag at high lifting properties. The optimum distance from a wing to a water surface afloat ensures positive influence of wing-in-ground effect that diminishes take-off run.

The composite structure of the airframe allows to have rather small weight at high strength and the rigidity, therefore this airplane can carry high percent of an effective load.

The powerful and lightweight power unit allows to have a high cruising speed, a high rate of climb, short take-off run.



VAI-41 It is composed under the classical layout with the  high-wing position, the T-shaped tail unit, one turboprop engine with a pusher propeller, a tricycle retractable landing gear with a nose leg.

The cockpit and passengers ensures good ergonomics and comfort, the good review, convenience of boarding and deboarding, safety of escape on water and on the land. For an input and an exit from a cabin two canopy doors, on left and on starboard open.

On a fuselage surface there are small steps for facilitation of a entrance in a cabin.

For crew and passengers comfortable seats are established. Crew seats are regulated. The seat-back angle of inclination is 17 degrees, ensures the comprehensible review and convenience of landing.

The airplane is equipped by a standard package of instrumentation, and also GPS-navigation system.

The power unit is powerful small-size PBS TP100 turboprop with a pusher propeller, mounted on a pylon. The pylon has a strong and rigid construction for loadings perception from the engine. At choosen airplane layout this is optimal engine positioning.

The engine in a batch production also is operated on several types of airplanes and helicopters.

The turboprop power unit on a number of parametres has a number of advantages before piston, such as high specific power, small weight and the sizes, in fuel grade aviation kerosene is applied.

One of the principal advantages to a seaplane that a running propeller is shielded by a fuselage and by a wing from hit of water streams and splashes on taxiing, taking-off and run. Besides, such arrangement of a propeller diminishes noise level in a cabin and does not disturb to disembarkation-landing in the airplane. The pusher propeller intensively blows in a tail unit, improving controllability.

Airframe parts and units are made of composite materials with glassfibre using, and in especially loaded places is applied carbonfibre.

All metal parts and units, power unit, landing gear are made of corrosion-resistant materials or have safe anticorrosive cover.

The fuselage has a semimonocoquestructure.The fuselage bottom is single step. It has the special geometry, allowing to have comprehensible parametreshydrogliding and seaworthiness, perceptions of hydrodynamic loadings, and also the aerodynamic form, the review and convenience to crew and passengers. In the fuselage nose is placed the landing gear forward legwheel well, further there is a four-seater cabin, behind a cabin is situated a luggage compartment. Behind it there is a LG main legs compartment. 

 VAI 41 02


The fuselage is divided into four compartments and has the cavities filled with foam for confinement afloat in case of damage.

Airplane wing is single-spar, tapered shape. On the wing trailing edge are disposed highly effective single-slotted flaps and ailerons. In a wing firmware fuel tanks place. On wing tips are lateral stability floats. The majority of seaplanes and amphibians have a small roll afloat in view of features of layout. In first half of taking-off this roll is parried by an ailerons turn and the airplane receives a level attitude.

The tail unit has T-shaped layout, includes a fin, the stabilizer, an elevator, a rudder.

The T-shaped empennage has the big efficiency in comparison with deck in view of that from a wing and a fuselage the adverse effect of vortexes is diminished by the stabilizer, efficiency of a fin and a rudder thanks to positive influence of the stabilizer improves, besides, highly raised stabilizer and elevators are not exposed blows of waves and water streams. Thanks to close disposed pusher propeller blowing of control surfaces that improves controllability, especially at low speeds is increased.

Kiel is made one-piece with a fuselage. A construction of plumage and control surfaces spar with a rigid composite skin. All control surfaces are equipped by trim tabs.

The tricycle retractable landing gear with a forward leg simplifies airplane piloting on taxiing, take-off and landing, such layout also improves a forward view on the taxing.

LG-forward leg is self-oriented, leaf-spring type.

The main legs of lever type, have hydraulic shock-absorbers and differential braking. All legs of a landing gear are removed in the special wheels well disposed above a waterline in a nose and central part of a fuselage.

For an exception of damage of a tail part of a fuselage there is a small safety leg.

The flight control system is fully manual. Control is dual, in the cockpit there are mounted two control column. Conducting of an elevator and ailerons are rigid thrusts, rudder conducting is cord.


VAI 41 03




Take-off  weight 1280 kg 2825 lbs
Empty  650 kg 1430 lbs


Wing Span 11,9 m 25,8 ft
Aspect ratio 10,2
Sweepback  angle 00
Dihedral  angle +30
Wing Area 12,8 m2
Wing loading 102 kg/m2 21 lb/ft2
Airplane length 7,85 m 25,7 ft
Airplane height 2,4 m 7,85 ft
Cabin dimensions
height 1,15 m 3,77 ft
width 1,18 m 3,87 ft
length 2,25 m 7,38 ft
Luggage compartment
Volume 0,12 m3 4,3 m3

VAI 41 04

VAI-41  cockpit  contains  four  persons, the canopy doors open sideways for access


Total  capacity:      4 men
   passengers 3 men
   crew 1 man
Stoll  speed     105 km/h       57 kts
Cruise  speed 265 km/h      145 kts
Top  speed 310 km/h 170 kts
Range 1200 km 650 nm
Optimal  flight altitude 4500 m 14750 ft
    Runway 500 m 1600 ft


 Power Unit

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Power  unit
Manufacturer PBS (Czech republic)
Type TP100
Maximum  power 1 х 250 hp
Dry  weight 65 kg 145 lbs
Fuel    type Jet A, A1, B, ТС-1, Т2,  РТ