Building my own homemade airplane - a biplane - has been my dream since childhood. However, I was able to implement it not so long ago, although I paved the way to the sky in military aviation, and then on a hang-glider. Then he built an airplane. But the lack of experience and knowledge in this matter also produced a corresponding result - the plane never took off.
The failure did not exactly discourage the desire to build aircraft, but it cooled the ardor thoroughly - a lot of time and effort had been spent. And what helped revive this desire was, in general, an incident when the opportunity arose to inexpensively purchase some parts from a decommissioned An-2 aircraft, better known among the people as the “Corn Man”.
And I only purchased ailerons with trim tabs and flaps. But from them it was already possible to make wings for a light biplane aircraft. Well, the wing is almost half the plane! Why did you decide to build a biplane? Yes, because the aileron area was not enough for a monoplane. But for a biplane it was quite enough, and the wings from the An-2 ailerons were even shortened a little.
Ailerons are located only on the lower wing. They are made from twin aileron trimmers of the same An-2 aircraft and are suspended on the wing on ordinary piano hinges. To increase the efficiency of aircraft control, wooden (pine) triangular slats 10 mm high are glued along the trailing edge of the ailerons and covered with strips of covering fabric.
The biplane aircraft was conceived as a training aircraft, and according to the classification it belongs to ultra-light devices (ultralights). By design, the homemade biplane is a single-seat, single-strut biplane with a tricycle landing gear with a steerable tail wheel.
I couldn’t find a prototype, so I decided to design and build according to classic scheme and, as motorists say, without additional options, that is, in the simplest version with an open cockpit. The upper wing of the “Grasshopper” is raised above the fuselage (like a parasol) and fixed slightly in front of the pilot’s cabin on a support made of duralumin pipes (from the An-2 aileron rods) in the shape of an inclined pyramid.
The wing is detachable and consists of two consoles, the joint between which is covered with a cover. The wing set is metal (duralumin), the covering is linen impregnated with enamel. The wing tips and root parts of the wing consoles are also covered with a thin duralumin sheet. The upper wing consoles are additionally supported by struts running from the attachment points of the inter-wing struts to the lower fuselage spars.
The air pressure receiver is fixed at a distance of 650 mm from the end of the left upper wing console. The lower wing consoles are also detachable and are attached to the lower fuselage spars (on the sides of the cabin). The gaps between the root part and the fuselage are covered with linen (impregnated with enamel) fairings, which are attached to the consoles with adhesive tapes - burdocks.
The installation angle of the upper wing is 2 degrees, the lower one is 0 degrees. The transverse V at the upper wing is 0, and at the lower one it is 2 degrees. The sweep angle of the upper wing is 4 degrees, and that of the lower wing is 5 degrees.
The lower and upper consoles of each wing are connected to each other by struts made, like the struts, from duralumin pipes from the control rods of the An-2 aircraft. The fuselage frame of a homemade biplane is a truss, welded from steel thin-walled (1.2 mm) pipes with an outer diameter of 18 mm.
Its basis is four spars: two upper and two lower. Along the sides, pairs of spars (one upper and one lower) are connected by an equal number and equally spaced posts and struts and form two symmetrical trusses.
Pairs of upper and lower spars are connected by cross members and jibs, but their number and location at the top and bottom often do not coincide. Where the location of the crossbars and posts coincide, they form frames. Form-forming arcs are welded on top of the front rectangular frames.
The remaining (rear) fuselage frames are triangular, isosceles. The frame is covered with unbleached calico, which is then impregnated with “enamel” homemade- celluloid dissolved in acetone. This coating has proven itself well among amateur aircraft designers.
The front part of the biplane fuselage (up to the cockpit) on the left side in flight is covered with panels of thin plastic. The panels are removable for easy ground access to controls in the cab and under the engine. The fuselage bottom is made of 1 mm thick duralumin sheet. Tail airplane - biplane - classic. All its elements are flat.
The frames of the fin, stabilizer, rudders and elevators are welded from thin-walled steel pipes with a diameter of 16 mm. The linen covering is sewn to the frame parts, and the seams are additionally taped with strips of the same calico fabric impregnated with enamel. The stabilizer consists of two halves that are attached to the keel.
To do this, an M10 pin is passed over the fuselage through the keel near the leading edge, and a tubular axis with a diameter of 14 mm is passed at the trailing edge. Ears with sector grooves are welded to the root rods of the stabilizer halves, which serve to install the horizontal tail at the required angle, depending on the mass of the pilot.
Each half is placed with an eye on a stud and secured with a nut, and the trailing edge tube is placed on the axle and pulled to the keel by a brace made of steel wire with a diameter of 4 mm. From the editor. To prevent spontaneous rotation of the stabilizer in flight, it is advisable to make several holes for a pin instead of a sector groove in the ears.
Now the biplane aircraft has a propeller-driven installation with an engine from the Ufa Motor Plant UMZ 440-02 (the plant equips the Lynx snowmobiles with such engines) with a planetary gearbox and a two-bladed propeller.
Engine with a volume of 431 cm3 and a power of 40 hp. with a speed of up to 6000 per minute, air-cooled, two-cylinder, two-stroke, with separate lubrication, runs on gasoline, starting with AI-76. Carburetor - K68R Air cooling system - although homemade, it is effective.
It is made in the same way as the Walter-Minor aircraft engines: with an air intake in the shape of a truncated cone and deflectors on the cylinders. Previously, the biplane aircraft had a modernized engine from the Whirlwind outboard motor with a power of only 30 hp. and V-belt transmission (gear ratio 2.5). But even with them the plane flew confidently.
But the homemade two-bladed monoblock (from pine plywood) pulling propeller with a diameter of 1400 mm and a pitch of 800 mm has not yet been changed, although I plan to replace it with a more suitable one. The planetary gearbox with a gear ratio of 2.22... the new engine came from some foreign car.
The engine muffler is made from a ten-liter foam fire extinguisher cylinder. The fuel tank with a capacity of 17 liters is from an old tank washing machine- it is made of stainless steel. Installed behind the dashboard. The hood is made of thin sheet duralumin.
It has grilles on the sides for the outlet of heated air and on the right there is also a hatch with a cover for exiting the cord with a handle - they start the engine. The propeller-engine installation on a homemade biplane is suspended on a simple motor mount in the form of two consoles with struts, the rear ends of which are fixed to the struts of the front frame-frame of the fuselage frame. The aircraft's electrical equipment is 12-volt.
The main landing gear legs are welded from sections of steel pipe with a diameter of 30 mm, and their struts are welded from pipes with a diameter of 22 mm. The shock absorber is a rubber cord wound around the front pipes of the struts and the trapezoid of the fuselage frame. The wheels of the main landing gear are non-braking with a diameter of 360 mm - from a mini-mokie, they have reinforced hubs. The rear support has a spring-type shock absorber and a steerable wheel with a diameter of 80 mm (from an aircraft stepladder).
Control of the ailerons and elevator is rigid, from the aircraft control stick through rods made of duralumin tubes; The rudder and tail wheel are cable driven, from the pedals. Construction of the aircraft was completed in 2004, and it was tested by pilot E.V. Yakovlev.
The biplane aircraft passed the technical commission. He made quite long flights in a circle near the airfield. A fuel supply of 17 liters is enough for about an hour and a half of flight, taking into account the aeronautical reserve. Very useful tips and consultations during the construction of the aircraft were given to me by two Evgenii: Sherstnev and Yakovlev, for which I am very grateful to them.
Homemade biplane “Grasshopper”: 1 - propeller (two-blade, monoblock, diameter 1400.1 = 800); 2- muffler; 3 - cockpit fairing; 4- hood; 5 - upper wing console strut (2 pcs.); 6- rack (2 pcs.); 7 - upper wing pylon; 8- transparent visor; 9 - fuselage; 10-keel; 11 - steering wheel; 12 - tail support; 13 - tail steering wheel; 14-main landing gear (2 pcs.); 15 - main wheel (2 pcs.); 16 - right console of the upper wing; 17-left upper wing console; 18 - right console of the lower wing; 19-left lower wing console; 20-air pressure receiver; 21 - lining for the joint of the upper wing consoles; 22 - stabilizer and keel brace (2 pcs.); 23 - engine hood with air intake; 24 - gas flap; 25 - stabilizer (2 pcs.); 26 - elevator (2 pcs.); 27-aileron (2 pcs.)
Steel welded frame of the biplane fuselage: 1 - upper spar (pipe with a diameter of 18x1, 2 pcs.); 2- lower spars (pipe with a diameter of 18x1, 2 pcs.); 3 - aircraft control stick support; 4 - spinal beam (2 pcs.); 5-quadrangular frame (pipe with a diameter of 18, 3 pcs.); 6- forming arc of the first and third frames (pipe with a diameter of 18x1, 2 pcs.); 7 - struts and braces (pipe with a diameter of 18x1, according to the drawing); 8- lugs and lugs for fastening and suspension structural elements(as needed); 9 - trapezoid for fastening the rubber cord shock absorber of the main landing gear (pipe with a diameter of 18x1); 10-triangle tail frames (18x1 diameter tube, 4 pcs.)
Angles of installation of the wing consoles (a - upper wing; b - lower wing): 1 - transverse V; 2-swept wings; 3 - installation angle
Motor frame of a homemade biplane: I - spar (steel pipe 30x30x2.2 pcs.); 2-spar extension (pipe with a diameter of 22.2 pcs.); 3 - cross member (steel sheet s4); 4 - silent blocks (4 pcs.); 5-lug for fastening the strut (steel sheet s4.2 pcs.); 6 - hood support bow (steel wire with a diameter of 8); 7 strut (pipe diameter 22, 2 pcs.)
The main landing gear of the biplane: 1 - wheel (360 in diameter, from a mini-mokie); 2- wheel hub; .3 - main stand (steel pipe with a diameter of 30); 4 - main strut (steel pipe with a diameter of 22); 5 - shock absorber (rubber band with a diameter of 12); 6 - travel limiter of the main rack (cable with a diameter of 3); 7 - shock absorber mounting trapezoid (fuselage truss element); 8- fuselage truss; 9 additional landing gear (steel coarse with a diameter of 22); 10- shock absorber grip (pipe with a diameter of 22); 11 - additional strut (steel pipe with a diameter of 22); 12 rack connection (steel pipe with a diameter of 22)
Instrument gloss (at the bottom you can clearly see the rudder and tail wheel control pedals on the trapezoid and the rubber shock absorber of the main landing gear): 1 - carburetor throttle control handle; 2 - horizontal speed indicator; 3 - variometer; 4 - instrument panel mounting screw (3 pcs.); 5—turn and slide indicator; 6-light engine failure alarm; 7 - ignition switch; 8-cylinder head temperature sensor; 9 - rudder control pedals
On the right side of the hood there is a long window air filter carburetor engines and engine starting device
The UM Z 440-02 engine from the Lynx snowmobile fit well into the contours of the fuselage and provided the aircraft with good flight performance
Drawings of a radio-controlled model of a biplane (seaplane) aircraft
Read also: DIY snowmobile: and
I attached the tail booms with glue to the ribs of the central section of the wing. I cut off the ailerons from the outer sections. I glued flexible strips of computer floppy film into the wing at the aileron suspension points. They will act as hinges (photo 8). The rear tail planes were also reinforced with carbon rods.
Before assembling the model, I first tried on the upper wing to the lower one and the tail parts.
I glued the tail booms to both wings (upper and lower). I combined the wings with the beams using 4 spacers. The tail unit was assembled separately using glue. Once the wings were glued together, I attached the tail to them.
The control servos were mounted traditionally. I cut a hole in the foam for the servo drive and glued rectangles from pieces of a ruler measuring approximately 7x15 mm, having previously drilled 01 mm holes in them for screws. After waiting for the glue to dry, I fastened the servo machine with the screws that were included in its kit (photo 10).
I cut out the blanks for the hinges of the drive rockers using a utility knife from a ruler. Between the 5x10 mm rectangles I inserted a 5x5 mm square and glued this bag together with Moment superglue. I rounded the upper part of the workpiece on the sandpaper, and then drilled a hole in it (photo 11). I glued the finished loop to the aileron (photo 12).
A rod made of a carbon strip with a cross-section of 3×1 mm, connecting the ailerons of both wings, was fixed in a loop with a piece of rod (made of the same carbon) (photo 13). Then I started adjusting the size of the rods, since the lower and upper wings have different transverse angles. Two rudders were also connected (photo 14).
Since carbon fiber cracks and is difficult to drill, the idea came to make the rods from an ordinary Soviet wooden ruler, and make the axles from a paper clip.
The model would have turned out to be a little heavier, but given the high power supply of the model, such an increase in weight would be justified.
Two rudders are also connected by a similar rod (photo 15). The struts between the wings and the hinge rods that connect the ailerons are clearly visible in the side view of the model.
The lower part of the fuselage was coated with yacht varnish and the entire assembly was left to dry for a day.
Making thrust for a biplane seaplane
The tips for the carbon rods were bent from 01 mm steel wire (such wire can be bought in Moscow at the E-Fly store. Of course, they can also be made from a paper clip.
I bent the wire with pliers (photo 16). trying to keep the step height about 5 mm. I bit off the tip with side cutters (photo 17). The tip was screwed to the carbon rod (01.5 mm rod) with thread (photo 18). The joint was impregnated with Titan glue.
First, I installed the rod on the “hog” of the steering wheel plane, then I put the servo rocker on it and then secured it to the drive axis.
Installing an engine on a model airplane
The foundation for the engine was a piece of ruler. To attach the model's engine flange to it, I spent a long time looking for microscrews, but then decided to glue it with cyacrine glue (photo 19, 20). I tried to tear off the flange after attaching it, but it didn’t work.
The frame with a pre-mounted 2730 engine looks pretty good.
I put the power unit in its place. Photo 21 shows the location of the servos; they control the rudder and elevator.
Making floats
Since it was decided to assemble a seaplane, it was necessary to make floats for it. By the way, they can also serve as skis for taking off and landing the model in winter.
I chose the width of the floats to be 30 mm, and the height to be 40 mm. I collected them in one sitting. I glued the patterns together into a box. But with the size, it seems, I missed the mark. Subsequently, it turned out that the biplane did not want to take off from the fresh, loose snow.
The float skis needed to be made wider and longer. The bent float runner had to be glued under the load. Painted the floats acrylic paint. Then I covered them with two layers of domestically produced Bor yacht varnish.
I was hoping to simply glue the floats to the tail booms located below, but it seemed that such a fastening would be unreliable. I had to glue another rib under each float. Now each of them rests in two places: one on the tail boom, and the other on a rib from a single ceiling (photo 22).
The Korona receiver, which has 4 channels in the 35 MHz range, is installed in the fuselage.
I ran the antenna under the tail, initially placing it under the wing and running along the tail beam. (photo 23).
The fuselage was initially designed to accommodate a battery with a capacity of 8,610 mAh. But it’s good that it turned out to be wider, and larger batteries of 750 mAh and 1000 mAh fit into it (photo 24). In practice, they didn’t even need to be secured additionally.
Control weighing showed that the flight weight of the model (with a battery with a capacity of 750 mAh and a voltage of 11.4 V) was equal to 340 g.
The model's flight took place on Saturday, in mid-March. The ice on the pond turned out to be strong and had not yet begun to melt, although the temperature was already above zero - +2 C. What was most worrying was that the breeze was three meters per second. Therefore, in order to carry out a vertical takeoff, it was necessary to guess the moment when the wind subsides.
A couple of times before the start the model was overwhelmed by gusts.
I was afraid to lift the seaplane myself. Mainly because I wanted to objectively evaluate how it flies and whether it is generally suitable for flight. An experienced pilot was needed who could determine the flight qualities of the model.
The tests were carried out by experienced modeler and pilot Konstantin Ivanishchev (photo 26). First, he launched from his hand, then from a well-trodden path, and only then - vertically.
After conducting several flight tests on a 750 mAh battery, we changed it to a more capacious (1000 mAh) and heavier one. The alignment has improved somewhat because its center has moved to the front edge of the wing.
Tests continued until the accident: the float was torn and the nose was torn off.
As in large aviation, the “human factor” played a fatal role.
Damage to the seaplane was still minor. They were eliminated in a matter of minutes.
In order for the reader to receive an objective conclusion on the flight results, I will give the tester’s assessment.
Impressions from this radio-controlled model
Yuri's radio-controlled models are always very unusual. Even the appearance of his new model turned out to be unlike any other.
The hydroplane biplane turned out to be simply wonderful: it flew confidently.
After I got used to its response to the controls, I began to try takeoff and landing on snow.
Despite the looseness of the snow, all the floats of the runners confidently held this radio-controlled aircraft model on it. Vertical take-off also turned out to be possible, which allows the model to be launched from any site.
In the air, the hydroplane is stable, the large angle of the transverse “V” of its planes ensures controllability only with the help of elevators and rudder.
The motor of the biplane model even has excessive power. In principle, you can “fly” perfectly at a third of its power. If you increase it to two-thirds, the screw begins to flutter, which can be corrected by installing another type of screw - for example DD.
The model is so stable in flight and obedient to the rudders that it can be a “desk” for beginning aircraft modellers.
Do-it-yourself radio-controlled seaplane - detailed photo of production
Radio-controlled model equipment
Homemade aircraft, drawings of machines and their brief descriptions built by amateur designers
PHOENIX M-5
A model that is equipped with two Vikhr-25 engines modified for air cooling. The design of the handle and the control circuit of the machine have no analogues in the world. Famous test pilots did not hide their delight, and even recommended its use on military fighters.
The take-off weight of the vehicle is two hundred and fifty-five kilograms, and the wing surface area is five point six square meters.
VOLKSPLAN
The model was designed by an American amateur designer, with a pulling screw, which consists of the following components:
Shaft (1), made of duralumin pipe
fuselage spar (2), the material from which is made – pine
casing (3), made of plywood three millimeters thick
wing spars (4)
arc (5)
tank (6), which holds thirty liters of fuel
frame (7), made of plywood thirty millimeters thick
automobile engine (8), the power of which is sixty horsepower
hood (9), made of fiberglass
spring (10)
technological holes for installing wings (11)
fender braces (12)
its racks (13)
his braces (14)
bolt for installing the strut (15)
Specifications:
Take-off weight is three hundred and forty kilograms
wing area is nine point twenty nine square meters
speed - one hundred seventy kilometers per hour
This model passed certification tests and was found fit for use; moreover, it was possible to perform aerobatic maneuvers and even a “corkscrew” on it.
AGRO-02
Created by Tver designers. The main material used in its manufacture is plywood, canvas, pine and the domestic RMZ-640 engine. The take-off weight of which was two hundred thirty-five kilograms and the wing area was six point three square meters.
KhAI-40
Designed by students of the Kharkov Aviation Institute. The model has a beam fuselage.
SINGLE SEAT AIRCRAFT BIPLANES
SINGLE BEAM PLANES
You have decided to build an airplane. And immediately you are faced with the first problem - what should it be like? Single or double? Most often this depends on the power of the existing engine, availability necessary materials and tools, as well as the size of the “hangar” for building and storing the aircraft. And in most cases, the designer has to opt for a single-seat training aircraft.
According to statistics, this class of aircraft is the most widespread and popular among amateur designers. For such machines, a variety of designs, types of structures and engines are used. Equally common are biplanes, monoplanes with low and high wings, single and twin engines, with pulling and pushing propellers, etc.
The proposed series of articles contains an analysis of the advantages and disadvantages of the main aerodynamic designs of aircraft and their design solutions, which will allow readers to independently evaluate the strengths and weak sides various amateur designs, will help you choose the best one and the most suitable for construction.
WITH AN AIRCRAFT - ONE ON ONE
One of the most common amateur schemes single-seat aircraft is a strut-braced monoplane with a high wing and a pulling propeller. It should be noted that this scheme appeared in the 1920s and has remained virtually unchanged throughout its existence, becoming one of the most studied, tested and constructively developed. The characteristic features of an aircraft of this type are a wooden two-spar wing, a welded steel truss fuselage, fabric covering, a pyramidal landing gear and a closed cockpit with a car-type door.
In the 1920s - 1930s, a variation of this scheme became widespread - a parasol type aircraft (from the French parasol - sun umbrella), which was a high-wing aircraft with a wing mounted on struts and struts above the fuselage. “Parasols” are still found in amateur aircraft construction today, but they are, as a rule, structurally complex, less aerodynamically advanced and less convenient to operate than classic high-wing aircraft. In addition, such devices (especially small sizes) access to the cabin is very difficult and, as a result, the difficulty of leaving it in an emergency.
Single-seat high-wing aircraft:
Engine - LK-2 with a power of 30 hp. designs by L. Komarov, wing area - 7.8 m2, wing profile - ClarkU, take-off weight - 220 kg (pilot - 85 kg, power plant - 32.2 kg, fuselage - 27 kg, landing gear with skis - 10.5 kg , horizontal tail - 5.75 kg, wing with struts - 33 kg), maximum speed - 130 km/h, flight range with a fuel supply of 10 l - 180-200 km
Engine - “Zundapp” with a power of 50 hp, wing area - 9.43 m2, take-off weight - 380 kg, empty weight - 260 kg, maximum speed -150 km/h, rate of climb at the ground - 2.6 m/s , flight duration -8 hours, stall speed - 70 km/h
The advantages of high-wing aircraft include the simplicity of piloting techniques, especially if the specific wing load does not exceed 30 - 40 kg/m2. High-wing aircraft are distinguished by good stability, excellent takeoff and landing characteristics, they allow rear alignment of up to 35-40% of the average aerodynamic chord (MAC). From the cockpit of such a device, the pilot is provided with optimal downward visibility. In short, for those who are building their first plane, and who are also planning to learn how to fly it on their own, better scheme can't imagine.
In our country, amateur aircraft designers have repeatedly turned to the braced high-wing aircraft design. Thus, at one time, a whole squadron of “parasol” aircraft appeared: “Baby” from Chelyabinsk, created by former pilot L. Komarov, “Leningradets” from St. Petersburg, built by a group of aircraft modelers led by V. Tatsiturnov, a high-wing aircraft designed by machine operator V. .Frolov from the village of Donino near Moscow.
We should tell you more about the last device. Having studied well the most simple diagram braced high-wing aircraft, the designer carefully planned his work. The wing was made of pine and plywood, the fuselage was welded from steel pipes and these elements of the aircraft were covered with fabric using classical aviation technology. I chose large wheels for the landing gear so that I could fly from unprepared ground areas. The power unit is based on a 32-horsepower MT-8 engine, equipped with a gearbox and a propeller large diameter. Aircraft take-off weight - 270 kg, flight centering - 30% GR, specific wing load - 28 kg/m2, wingspan - 8000 mm, propeller thrust in place - 85 kgf, maximum speed - 130 km/h, landing - 50 km /h.
Test pilot V. Zabolotsky, who flew over this device, was delighted with its capabilities. According to the pilot, even a child can control it. The aircraft was operated by V. Frolov for more than ten years and participated in several SLA rallies.
The test pilots were no less delighted by the PMK-3 aircraft, created in the town of Zhukovsky near Moscow by a group of amateur aircraft designers under the leadership of N. Prokopets. The vehicle had a unique forward fuselage, a very low landing gear and was designed according to the design of a strut-braced high-wing aircraft with a closed cockpit; a door was provided on the left side of the fuselage. The wing is slightly beveled back to ensure the necessary alignment. The design of the aircraft is all wood, covered with canvas. The wing is single-spar, with pine flanges, a set of ribs and the wing forehead are covered with plywood.
Wing area - 10.4 m2, wing profile - R-W, take-off weight - 200 kg, fuel reserve - 13 l, flight balance - 27% MAR, static propeller thrust - 60 kgf, stall speed - 40 km/h, maximum speed - 100 km/h, flight range - 100 km
The fuselage is based on three spars, and therefore the fuselage had a triangular cross-section. The plumage and control system of the PMK-3 aircraft are made like that of the famous training glider B. Oshkinis BRO-11 M. The basis of the power plant is a 30-horsepower outboard outboard motor"Whirlwind" with liquid cooling; at the same time, the radiator protruded slightly from the right side of the fuselage.
An interesting type of amateur-built high-wing braced aircraft was Don Quixote, developed in Poland by J. Yanovsky. WITH light hand enthusiast of amateur aircraft construction, famous glider test pilot and journalist G.S. Malinovsky, who published the drawings of “Don Quixote” in the magazine “Modelist-Konstruktor”, this, in general, not entirely successful scheme became very widespread in our country - at SLA rallies there were sometimes more than four dozen similar devices. Professional aircraft designers, however, believe that amateur aviators were attracted to this scheme primarily by its unusual nature. appearance aircraft, but it was precisely in it that some “pitfalls” were hidden.
Characteristic feature“Don Quixote” had a forward-facing cockpit, which provided excellent visibility and comfortable seating for the pilot. However, on an extremely light aircraft weighing up to 300 kg, the alignment changed significantly in the case when, instead of an 80-kg pilot, a more slender one, weighing 60 kg, sat in the cockpit - the device suddenly turned from overly stable to completely unstable. This situation should have been avoided even when designing the car - it was only necessary to install the pilot’s seat at its center of gravity.
Airplanes with a pusher propeller, designed according to the Don Quixote airplane design:
Engine power - 25 hp, wing area - 7.5 m2, empty weight - 150 kg, take-off weight - 270 kg, maximum speed - 130 km/h, rate of climb at the ground - 2.5 m/s, ceiling - 3000 m, flight range - 250 km. Machine design - all wood
Engine power - 30 hp, wingspan -7 m, wing area - 7 m2, empty weight - 105 kg, take-off weight - 235 kg, maximum speed - 160 km/h, rate of climb - 3 m/s, flight duration - 3 hours
Construction - fiberglass, engine power - 35 hp, wingspan - 8 m, wing area - 8 m2, wing profile - Clark YH, take-off weight - 246 kg, empty weight - 143 kg, flight balance - 20% MAC, maximum speed - 130 km/h
Another feature of Don Quixote is the landing gear with a tail wheel. As is known, such a scheme, in principle, does not ensure the directional stability of a light aircraft when moving along the airfield. The fact is that the movements of the aircraft, with a decrease in its mass and moments of inertia, become fast, sharp, short-period, and the pilot has to focus all his attention on maintaining the direction of the takeoff or run.
The A-12 aircraft from the Aeroprakt club (Samara), which was one of the copies of Don Quixote, had exactly the same congenital defect as the firstborn of this galaxy, however, the designers, after testing the machine by professional pilots V. Makagonov and M Molchanyuk quickly found an error in the design. By replacing the tail wheel on the A-12 with a nose wheel, they completely eliminated one of the main disadvantages of the Polish-design aircraft.
Another significant drawback of Don Quixote is the use of a pusher propeller, obscured in flight by the cockpit and wing. At the same time, the efficiency of the propeller dropped sharply, and the wing, not blown by the air flow from the propeller, did not provide the calculated lifting force. As a result, takeoff and landing speeds increased, which led to a longer takeoff and run, and also reduced the rate of climb. With a low thrust-to-weight ratio, the plane might not get off the ground at all. This is exactly what happened at one of the SLA rallies with the Elf plane, built according to the Don Quixote scheme by students and employees of the MAI.
Of course, building aircraft with a pushing propeller is not at all prohibited, but the need and feasibility of creating an aircraft with such a power plant in each specific case should be carefully assessed, since this will inevitably lead to losses in thrust and lift of the wing.
It should be noted that designers who creatively approached the use of a power plant with a pusher propeller managed to overcome the disadvantages of such a scheme and create very interesting options. In particular, several successful devices based on the “Don Quixote” scheme were built by P. Atyomov, a machine operator from the city of Dneprodzerzhinsk.
Wing area - 8 m2, take-off weight - 215 kg, maximum speed - 150 km/h, stall speed - 60 km/h, rate of climb at the ground - 1.5 m/s, operating load range - from +6 to -4
1 - metal wing sock; 2 - tubular wing spar; 3 - flap; 4 - tubular spars of the aileron and flap; 5 - aileron; 6 - engine control handle; 7 - Entrance door cockpit (right); 8 - engine; 9 - aileron control rod; 10 - strut in the plane of the wing; 11 - riveted duralumin fuselage beam; 12 - tubular spars; 13 - speed indicator; 14 - ignition switch; 15 - altimeter; 16 - variometer; 17 - slip indicator; 18 - cylinder head temperature indicator; 19 - flap control handle; 20 - dorsal parachute
A well-flying airplane with a pushing propeller was created by a team of amateur aircraft designers from the “Flight” club of the Samara Aviation Plant under the leadership of P. Apmurzin - this machine was called “Crystal”. Test pilot V. Gorbunov, who flew it, did not skimp on his high praise - according to his reviews, the car had good stability, was light and easy to control. The Samarians managed to ensure high efficiency of the flaps, which were deflected by 20° during takeoff and by 60° during landing. True, the rate of climb of this aircraft was only 1.5 m/s due to the shading of the pushing propeller by the wide cockpit. However, this parameter turned out to be quite sufficient for an amateur design - and this despite the fact that its take-off was somewhat difficult.
The attractive appearance of the "Crystal" is combined with the excellent production performance of the all-metal monoplane. The airframe fuselage is a duralumin beam riveted from 1-mm D16T sheets. The beam's load-bearing set also included several walls and frames curved from sheet duralumin.
It should be noted that in amateur designs it is quite possible to use plywood instead of metal, pine bars, plastics and other available materials.
In the bend of the fuselage beam, in its forward part, there was a cabin, covered with a large transparent faceted canopy and a light fairing made of D16T sheet 0.5 mm thick.
The braced wing is an original single-spar design with a spar made of 90x1.5 mm duralumin pipe, which absorbs the loads from bending and torsion of the wing. A set of ribs made of 0.5 mm D16T, stamped into rubber, was secured to the spar with rivets. The wing strut is made of duralumin tube 50x1 and is ennobled with a fairing made of D16T. In principle, duralumin spars and struts can be replaced with wooden, box-section ones.
The wing was equipped with ailerons and flaps with mechanical manual drive. Wing profile - R-III. The aileron and flap had spars made of duralumin pipes with a diameter of 30x1 mm. The wing forehead is made of 0.5 mm sheet D16T. The wing surfaces were covered with canvas.
The plumage is cantilever. The fin, stabilizer, rudder and elevator are also single-spar, with spars made of D16T pipes with a diameter of 50x1.5 mm. The plumage was covered with linen. The aileron control wiring had rigid rods and rockers, the wiring to the rudders was cable.
The landing gear is tricycle, with a steerable nose wheel. The landing gear on the aircraft was depreciated due to the elasticity of pneumatic wheels with dimensions of 255x110 mm.
The basis of the aircraft's power plant is a 35-horsepower two-cylinder engine RMZ-640 from the Buran snowmobile. The propeller is of wooden construction.
When comparing pulling and pushing propellers, you need to keep in mind that for devices with low power power plant, the first is more efficient, which was once superbly demonstrated by the French aircraft designer, an employee of the Aerospatial company, Michel Colomban, the creator of the small and very elegant “Cri-Cri” (cricket) aircraft.
It would not be superfluous to recall that the creation of small-sized aircraft with engines of minimal power has always attracted both amateurs and professionals. Thus, the designer of large aircraft O.K. Antonov, who had already built the flying giant An-22 “Antey” with a take-off weight of 225 tons, in his book “Ten Times First” spoke about his long-time dream - a small plane with a 16 hp engine. Unfortunately, Oleg Konstantinovich did not have time to create such a device...
Designing a compact aircraft is not as simple a task as it might seem at first glance. Many conceived it as an ultra-light vehicle with extremely low wing load. The result was ultra-light vehicles capable of flying only in the complete absence of wind.
Later, designers came up with the idea of using wings for such devices. small area and with a large specific load, which made it possible to significantly reduce the size of the vehicle and increase its aerodynamic quality.
Twin-engine low-wing aircraft:
B - plane "Pasya" by Edward Magransky (Poland) - good example creative development of the “Cri-Cri” scheme:
Power plant - two KFM-107E engines with a total power of 50 hp, wing area - 3.5 m2, wing aspect ratio - 14.4, empty weight - 180 kg; take-off weight - 310 kg; maximum speed - 260 km/h; stall speed - 105 km/h; flight range - 1000 km
1 - receiving air pressure from the speed indicator; 2 - duralumin propeller (maximum rotation speed - 1000 rpm); 3 - Rowena engine (cylinder displacement 137 cm3, power 8 hp, weight 6.5 kg); 4 - resonant exhaust pipe; 5 - membrane carburetor; 6 - fuel intakes - flexible hoses with weights at the ends (one per engine); 7 - gas sector (left side); 8 - handle for the trimmer effect mechanism (resetting the elevator spring loader); 9 - resettable part of the lantern; 10 - unsupported rocker in the rudder control cable wiring; 11 - hard wiring for stabilizer control; 12 - cable wiring of the rudder drive; 13 - all-moving horizontal tail; 14 - rudder rocker; 15 - keel spar; 16 - chassis with damping in compressed position; 17 - main landing gear spring; 18 - fuel tank drain pipe; 19 - aileron-flap hovering control handle (left side); 20 - fuel tank with a capacity of 32 l; 21 - cable wiring for controlling the nose landing gear; 22 - adjustable pedals; 23 - pedal loader (rubber shock absorber); 24-rubber shock absorber for the right landing gear; 25 - engine installation frame (steel V-shaped pipe); 26 - bow strut control rocker; 27 - wing spar; 28 - hovering aileron (deflection angles from -15° to +8°, hovering - +30°; 29 - foam frame; 30 - wing skin; 31 - hanging aileron mounting bracket; 32 - foam ribs; 33 - stabilizer tip (balsa ); 34 - stabilizer spar; 35 - aileron toe (skin - duralumin, filler - foam)
Flying on your own plane is not a cheap pleasure. Few people can afford to buy a factory light-engine aircraft with their own money. As for used factory aircraft, they also require a number of additional investments from their new owners: despite previous technical revisions, the new owner inevitably faces other people's problems. Fortunately, there is a solution to this problem. Home-built aircraft that have an EEBC certificate in the experimental category have become increasingly popular at gatherings of aviation enthusiasts.
Apart from the additional time spent on construction, amateur-built aircraft RV, Sonexes, Velocity and many others received well-deserved high marks for a low cost with excellent flight qualities that are not inferior to their factory counterparts. But, as often happens, there is back side homemade: For every completed hobby project, there are several that are abandoned. So, in order for the project to become successful, it is necessary to do right steps, have certain knowledge and be able to apply it.
Step 1. Selecting an aircraft model
Perhaps the goal of the project is the main factor influencing the success of the entire event before construction begins.
The beginning of an airplane project can be ranked in importance with a marriage proposal, the conclusion of an important deal, and even the choice of a pet. As in all previous cases, here you need to think through all the details before making a final decision.
Most of those who don't reach the finish line burn out over trifles. The grace of the Falco aircraft, the aerial acrobatics of the Pitts 12 and the mischievous flight of the Glastar: all can whet the interest of the future builder to make a decision based only on appearance. The simplicity of this solution can be deceiving. The essence of the right decision is not in external attributes, but in the purpose of construction.
For the right decision it requires completely honest and sincere self-examination. Of course, many people dream of flying like Viktor Chmal or Svetlana Kapanina, but is this true or not? Each person has his own personality and his own style of piloting, and it is impossible to live by someone else's experience. You can build an airplane for air tourism and long cross-country flights, but then discover that you would rather have a country picnic on a green lawn with friends 60 kilometers from the flying club. It is important to resolve all your doubts and sincerely think through the dream of having a “home plane”. After all, the main thing is to improve your life and do more of what you really like.
Once you decide on your dream, choosing a plane will not be difficult. After selecting the aircraft model, it will be time to conduct an examination. A quick glance at the 15th summer issue of Modelist - Constructor magazine will have a slightly sobering effect - perhaps because most of the aircraft models offered there have already gone out of fashion. The world of home cockpit builders has its own niche in the market, but even with a strong motivation, doing business in such a territory will not be an easy task from the economic side, because the market is very individualized, and trends replace each other, like swimsuit fashion. Before you start building, you should preparatory work: Analyze the aircraft design in detail, call people who have already worked on the project and look at the list of accidents. Starting work on an outdated project, in which parts and components are difficult to obtain, is, in principle, an expensive and costly undertaking.
Step 2: Planning your time
There are hardly a few people who have handled a project that requires as much attention, effort and time as building an airplane from scratch. This activity is not for amateurs. It requires constant and measured effort over a long period of time.
To ensure that there are fewer delays along the way and that progress on the project does not stand still, you can break down all the work into many small tasks. Working on each task will not seem so difficult, and success will come gradually as you complete each task. On average, a builder will need 15 to 20 hours per week to complete a project simple plane in a reasonable time.
For keen builders, most aeronautical projects take between two and four years to complete. On average, building an aircraft can take five or even ten years. This is why experienced aircraft builders will never set an exact date for the first flight, despite the constant questioning glances of friends. As an excuse, you can say “it’s not worth it” or “as soon as possible.”
There is no place for idealists here
Not all builders realize the importance of proper time management. Aircraft building is not a social endeavor, and in fact it can get pretty damn lonely while working. Sociable people may find this activity more difficult than one might imagine. Therefore, everyone who devotes himself to this work should find pleasure in working alone.
The next plane to be built without any gaps in the holes will be the first of all time. Robert Piercing, in his cult novel Zen and the Art of Motorcycle Maintenance, talks about mistakes when drilling holes. These mistakes can discourage a builder from working on a project for a long time. Such mistakes often accompany aviation projects, and if the builder does not have the personal qualities that would push him to cope with such difficulties, the project may be abandoned.
Perfectionists who strive for perfection in everything should look for another occupation. If all airplanes had to perfectly comply with the laws of aerodynamics, hardly anyone would dare to take off. Perfectionism is often mistaken for craft, but they are very different things. It doesn’t matter how good a thing is: you can always improve something, make it brighter and better. The goal is not to make the best airplane - the goal is to make a practical airplane so that the builder would not be ashamed of it and would not be afraid to fly it.
Step 3. Workshop equipment
Next important point- construction site. Not everyone can afford to have a workshop like the Cessna hangars. Size, in fact, does not play a decisive role in this case.
Light aircraft are built in basements, trailers, sea containers, village barns, as well as in adobe huts. In most cases, a two-car garage is sufficient. A single garage may also suffice if you have a dedicated storage area for winged units.
Most people believe that the best place for the construction of the aircraft is located in the hangar of the city airport. In reality, hangars are the least suitable for aviation projects. Most often, hangars are much warmer in the summer and colder in the winter than outside. They are poorly lit everywhere and are rarely near your home.
Regardless of where the aircraft is assembled, you should think about amenities. Investing in comfort, in some semblance of climate control, good lighting and desktop comfortable height, rubber mats on concrete floor- will more than pay for themselves.
Here's how Martin and Claudia Sutter describe their experience building an RV-6 in their living room: “In Texas, where there are always extreme temperature changes, air conditioning in the hangar would have cost us more than building the airplane itself. We thought about working in a garage, but as it turned out, our cars couldn't stand being exposed to the open sun for long. Therefore, breakfast in the bar, housing in the bedroom, and construction in the living room - this is how our work was organized. Amenities included domestic air conditioning, heating and large sliding doors that allowed the plane to be rolled out. The most important thing was that everything was always at hand"
Step 4. Where can I get money for the plane?
Second only to time is the issue of money. How much will it cost to build an airplane? There is no one-size-fits-all answer here: on average, such projects cost between $50,000 and $65,000, and real cost can be either lower or significantly higher. The construction of an aircraft is like a phased repayment of a loan; it is important to correctly assess the entire volume of required resources, both financial and time, before the start of the active investment phase.
Allocation of project costs begins with determining the tasks that the aircraft will solve. Modern aircraft manufacturers are ready to install everything you could possibly want on their products. Home aircraft builders, in turn, know exactly what they want. If the aircraft will not fly by instruments, then there is no need to install instrument flight equipment on it. There is no need to fly at night - why install runway lights for $1000. A constant pitch propeller costs three times less than a constant speed propeller, and in most cases is not much inferior to a constant speed propeller in terms of flight efficiency.
The right question is where to get the money? Rich Aunt Praskovya will not leave a will in time to finance the construction, so you will have to postpone your trip to the south, or increase your income.
Van's Air Force website owner Doug Reeves suggests the first approach. His book, "Ten Steps to Getting a Jet," includes putting off buying a new car, quitting cable TV, eating light, healthy meals of vegetables and fruits, and giving up unlimited phone plans in favor of economy plans. Overall, Doug estimates that adopting and following these steps allowed him to save about $570 each month. He faithfully put this amount into his piggy bank every month and now flies an RV-6.
Bob Collins, an RV builder, took a different route (not everyone who builds an airplane builds an RV). His job as an editor for public radio supported him and his family, but it wasn't enough to buy a plane. In general, he became “the oldest newspaper delivery man.” Seven days a week, from two to six in the afternoon, he delivered the local press. This activity, combined with his regular work, family life and airplane plans didn't leave him much time to sleep, but in the end he became the proud owner of an RV-7A.
Step 5. Where to get smart?
“I’ve never riveted, welded, or painted anything, and in general I’m not a master of gold,” an inexperienced builder may object. Am I even capable of building something as complex as an airplane?
In reality, it's not that difficult. Home-built airplanes are ordinary mechanical devices. Mechanical control units, simple and easy-to-understand electrics, almost no hydraulics - you can study and assemble everything yourself. A standard aircraft engine, for example, consists of four hoses, three cables and two wires. Well, if your knowledge is not enough, you can always find out the missing gaps from textbooks and manuals.
The aircraft construction technique is simple and obvious. Riveting can be mastered in one day, welding will require more time, but it is fun and almost free. IN Everyday life a lot of things are made from wood, wood processing techniques and tools have been brought to perfection, and everything can be mastered via the Internet and Youtube.
If when studying new information If a structured presentation of the material suits you best, you can take lessons in aircraft manufacturing. Similar events are held by kit kit manufacturers and some private builders.
Comprehensive support needed
If the dream of flying your own plane does not leave you, and enthusiasm fills you to the very top, then support from like-minded pilots will help speed up work on the project.
- The first step is to enlist the support of your family. Working hours in the workshop can be long and tiring, including for the rest of your family. Spousal and family support in such cases is simply necessary. Any aircraft projects that interfere with the relationship are doomed: “He spends all his time on this damn plane. She nags me all the time about my project,” whether it’s worth starting a project in this state of affairs. Mitch Locke adheres to a simple tactic: “Before I start building a new airplane, I go to my wife and ask her for a list of all the benefits that she wants her life to be better while I spend less time on her.” And it works: Mitch built seven airplanes on his own. At the same time, there are many projects that are carried out by family teams: parents with children, spouses. When shared teamwork brings people together, building an airplane becomes an additional opportunity to spend time with loved ones.
- Support outside the family circle is also important.
When choosing a decision in favor of a particular project, it is also important to take into account the service support and experience of previous builders. Is it possible to change the thickness of the ribs without compromising the safety of the structure? Will the aircraft model company be able to answer this question? How quickly will the answers come? Is there a forum for aircraft builders that can help newbies?
Tips on how to speed up work on a project - help from professionals and kits
One of the reasons for the growth in the number of home aircraft builders is the emergence of KIT kits. Most aircraft in the past were built from scratch. The builders purchased a set of drawings for the aircraft of their choice (or designed it themselves at their own peril and risk), and then ordered materials for the manufacture of parts and assemblies.
Here are some tips for those who decide to go this route:
- You can use virtual design programs, such as X-Plane: Aircraft designer David Rose uses this program to design his models, supplementing it with the Airplane PDQ package (total cost: $198). The cost of the package is low, and the capabilities are at the level industrial systems for $30,000.
- The structure can be designed: To do this, you can study Martin Hollman’s book “Modern Aircraft Design” or K. S. Gorbenko’s “We Build Airplanes Ourselves.”
If you are not ready to make a plane with clean slate, then it makes sense to think about buying a KIT set. The kit manufacturer can provide accurate and ready-to-assemble aircraft parts with significant savings in resources and materials compared to building from scratch. Assembly instructions, as opposed to engineering drawings, can save you countless hours of thinking about how parts fit together. This time saving will lead to the fact that you will be able to assemble more complex and high-tech aircraft. Today's KIT kits cover an astonishingly wide range of models, from wood and fabric models like the Piper Cub to composite models with prices comparable to the Citation.
Here is a list of kit manufacturers that aircraft manufacturers may find useful:
KIT – sets of Piper Cub PA-18 and its replicas
SKB "Vulkan-Avia"
CJSC Interavia
KIT – RV airplane kits
KIT – airplane sets C.C.C.P.
Your plane.ru
KIT – Ultra Pup airplane sets
KIT - CH-701 aircraft sets, as well as Zenit, Zodiac and Bearhawk
Avia-Comp Company
In order to legalize flights on a home-built aircraft, you will have to go through the procedure of obtaining a certificate of a single aircraft (EEVS, more details).
Construction may not be for everyone. If you love working with your hands and your head, know who to turn to for support, have enough money to buy a pickup truck, and have space to store it, you should be able to make your own airplane. Of course, this activity is not for everyone, but those who do it consider this experience one of the most exciting and joyful moments in their lives.
useful links
Websites dedicated to aircraft construction:
- www.stroimsamolet.ru
- www.reaa.ru
- www.avia-master.ru
- vk.com/club4449615 - VKontakte group with a lot of useful information
- www.avialibrary.com - library of aircraft designers
