First there appeared the idea of the multipurpose platform which allows the creation of aircrafts of many purposes and weight classes from ultra-light to sport plane, and also the four-seat plane. The possibility of getting different types comes only through changing the profile of loaded structural elements, power plant and equipment. Other parts, such as structural arrangement, geometry and ergonomics get small changes.
Based on these considerations there was made in the general 3D model of the aircraft, suitable for aerodynamic and strength calculations.
Then it was important to work out the ergonomics of the aircraft which will define the popularity of the plane equally with flight characteristics. The full-scale natural modeling of the cockpit in combination with construction elements of the fuselage shows the comfortability of boarding and dismount of the cabin crew, accessibility, shape and arrangement of the plane control. In this regard there was created the model of the cockpit which was checked on the arrangement of pilots, control levers, avionics and other equipment and types of the cabin decoration.
For the creation of the aircraft there was purchased the minimal necessary equipment including the sheet metal bending machine, three-shaft bender for the shaping of cover panels, pneumatic compressor, the 40-tonns hydraulic press and also the turning and milling machines for the quick mechanical operation. There were also purchased locksmith's benches and improvised stocks-tables. Their size was defined by the size of the wing.
The creation started from the fuselage. Its frame was constructed by riveting together 6063 square tubes with 2024 truss plates. The main shapes of the construction were made in the short period of time. However the frame will get its final shape long after when each bracket will be mounted for each aggregate.
Frames of wing, ailerons and tail consist of parts made of bent and stamped 2024 sheets.
Panels of fuselage cover, wing, tail and control surfaces are made of aluminum-composite three-layer panels thickness of 2 mm. They are clipped with the frame by glued-riveted connection. Panels are milled-out in the least stressed places to reduce the weight of the aircraft.
The wing struts consist of bent nose, tail and channel section spar. The spar has the steel doublers in points of attaching to the wing and fuselage. The aileron control rods run inside the wing struts. The top part of each strut connects with the wing and increases to the rear spar of the wing. The strut is also connected to this spar. The linear rod for aileron control runs inside this part.
The aircraft has a tailwheel-type landing gear. All the landing gears leg are of spring type. Each of front legs is bent of aluminum bands of 7075 alloy. Front gear legs are put into the nodes on the side of the fuselage are towards each other to the opposite side. Inside, racks have channels for braking the main wheels.
The spring of the tailwheel is a double bent sheet of spring steel.
The controls of the aircraft are fully paired and based on rigid rods. The manual control includes two control levers. These levers installed on the floor of the cabin on saddles with spherical plain bearings. Control levers are linked to each other by rectangular shaft. The wiring with two transitional rockers connects the back control lever with the elevator.
The central part of the shaft which connects control levers has the bracket with two flexible joints for the aileron control. They are connected with two rods. Tops of these rods are connected with transitional rockers on the fuselage.
Then the aileron controls run inside wing struts through rockers and rods.
The rudder pedals are of sledge type. Carriages with linear bearings move on steel. Each front pedal connected with the back one and also with the rocker and steel band. This steel band has slots for the adjustment of each pedal for pilot height.
The wiring from the rocker to the rudder pylon is two sequential rods connected through transitional rocker.
All the rods are made of 2024 tubes with riveted conic tips. Fluro unattended joint tips are installed there by thread connection. All the rockers and control pylons are miled of 2024 plate.
Both cabin doors open against the air flow. Each door installed on two hinges attached to the fuselage. Doors have the possibility of emergency discharge. The frame of the door is made of square 6063 tubes with the crossbeam. The top part of the frame is glazed with polycarbonate, while the bottom part covered with aluminum-composite panel.
Pilot seats are made of fiberglass and have special hollows for emergency spinal parachutes. Seats are fixed to fuselage with screws and can be removed.
The wing is attached to the fuselage by two nodes on front and rear spars and also by wing struts.
The windshield and top glass are made from a single sheet of a perimeter glued Lexan polycarbonate flush with the mating surfaces
Pilot seats are integrated to the power scheme of the fuselage. The backrest of the back seat is the part of bulkhead's side which divides the middle part of the fuselage and the tail unit beam. The front seat together with the linear tunnel, carcass of the dashboard and its case which are connected to legs on sides of the fuselage considerably increase the rigidity of the fuselage with cuts on the right side in torsion.
Shapes of both dashboards are trapezoid. Angles of side edges are of 45 degrees and they were chosen this way for their matching with horizon line during the horizontal flight and lists of 45 degrees.
Doors of the cabin open against the flight direction. This provides the comfortable boarding and out-boarding of the cabin crew. Each door has the emergency release mechanisms with its drive from each cabin.
After the long period of waiting we have finally received parts of the aircraft. The engine was the most awaited. Without the installation of the engine it was impossible to start the work with systems of the aircraft which are related to the engine. Now the plane stands on its legs, springs of which were made by „Grove” company under our drafts. The engine mount is ready and the engine installed with propeller.
The engine mount was made on specially prepared launching slipway. Its ring was also brought from the USA. The launching slipway undocked from knots of fixing of the engine mount on fuselage.
The tail leg which also came from abroad was combined with the spring. The current view of the aircraft shows how the fully assembled aircraft would look like. However there is the plenty of work left.
This is the way the doors open. We faced no problems with entrance and exit.
This is how the engine looks in relation to fuselage. The right centering plays significant role.
This is how the ready-assembled tail leg looks like. The tail gear flock is not mounted yet.
This is the engine control knob in the front cabin.
Here are the skid-type pedals with brake cylinders
Preliminary mount of side panels on the on-gear-standing aircraft. The final mount of panels on the left side is made after the mount of wiring of control, fuel lines and electric cords.
The aircraft on its gears with mounted panels of encasement and glazing. The preliminary common shape and view of aircraft can be seen. Consequently: the left side view — ¾ from the front side; the sideview; the view of ¾ from the back side.
Sideview of the right side. Here can be seen organs of aircraft and engine control.
Pilot cockpit view. Here are control parts and instrument panels.
Tail leg with mounted gear lock mechanism in the neutral position. The locked gear helps to keep the direction during the takeoff and landing. This is especially important with the presence of side wind. During the taxi the gear unlocks and becomes the free-oriented, providing necessary maneuverability.
The engine is wrapped with the cowl. For the creation of cowl there was used the „masque” of powerplant with similar engine. However, the air intake was elaborated. It foresees the installation of air filter. The „masque” is separable for easiness of use.
The side-view of the cowl. The cowl consists of top and bottom parts which are connected with top and bottom parts of the „masque”. It also consists of folding valves. Back parts of valves are made in form of „ears”. The air from the engine cooling system passes through these „ears”.
Back-right view of the cowl. Cooling system output ports can be seen precisely. The oil cooler can be seen in the right „ear”.
All assembled units were mounted on the aircraft for the preliminary weighting on December 18. Some of units were mounted temporarily as places for their final mount were not prepared. Thereby there was created the flight configuration of the aircraft nonmetering the fuel load. The aircraft was put on the flight line for defining of load of main gears and the tail wheel. The results of weighting by each separate gear give the ability to define the real centering of the aircraft in different flight configurations. The aircraft was weighted empty, with one pilot in front and back cabins and with both pilots.
The weight of the empty aircraft is 535 kilograms. Weight with one pilot equals 621 kilograms, with two pilots — 712 kilograms. The operation centering diapason allows using aircraft with any placement of the cabin crew including single pilot in both front and back cabins.
Three quarters right: the common view of the aircraft. There can be seen doors which open against the stream.
View from the right side shows the side view of the aircraft.
The left view was made from the high point and shows the top surface of the wing and top cockpit windows.
The back-right view allows seeing the placement of fuel tanks, lids closing fuel tanks compartments. They have the color of not uncovered aluminum for reducing of fuel heat by sunbeams.
The cowl view displays its construction: glass-fibre plastic front part and the metallic back part with folding leaflets.
The tail wheel view shows shape and construction of the spring, rotating part and the wheel. It also shows the locking mechanism with Bowden control of the wheel.
The tail unit has the folding manhole on the left side for the access to hinge plate bolts of the tail unit.
The supply tank, fuel pump and filter are place on the back of the cabin. The fuselage has special manholes for access, mounts and unmounts of units and for regular service.
The vertical and horizontal control is based on hard rods. These rods have intermediate cross beams. The left side of the fuselage has the folding manhole for service of these cross beams.
To be continued. The building of the aircraft is in process…