Technology towards the youth, in July 1975.

ANDREW SCREWS, engineer

The clouds on jet KIDS

Remember the colorfully decorated boxes full of round and rectangular plates, rods, axles, screws and nuts, with intrigues that given so many hours and days of our childhood?

"Design of all types and purposes and still fond of the boys, although the shelves full of gleaming varnish, but, alas, finished, and therefore uninteresting toys. The passion to break avtomobilchiki clockwork, to see how they work, and the preference that future technicians and engineers give a set of "machinery parts" - that the two sides of a simple psychological phenomenon that explains the interest is quite adults of all ages and professions to "home" aviation. Is not it interesting you can build harmonious, elegantly tailored airplane of carefully labeled pieces, equipped with its carefully-equipped engine, instruments, radio equipment, and finally soar, sensing not only the joy of flight, but also the legitimate pride of the aircraft? Designers for adults - semi-finished kits ultralight aircraft BD-5 "Micro", released on the Western market American aircraft designer James Bede - a successful psychological discovery of this talented engineer. Clearly triggered another circumstance: the price set no more than the cost of the car, while a proprietary light-engine Cessna costs to the private owner of ten p equals more expensive.

No matter how tempted by Bede in the ability to make private pilot buy "Micro", one of only a little psychology. Nice and very "good", the construction itself microplane, which has amazing flight performance.

"Since the press had the first information about the DB-5, - said the popular magazine" Flyugrevyu (Germany) - all aviation sports world is divided into two camps: some think Jim Bede, a charlatan, and the other a genius. " The main thing that strikes supporters and opponents of trouble - the rate at which flies its sleek airplane that looks like a "real" vsamdelishnaya machine.Since the 70-horsepower air-cooled two-stroke engine "Micro" accelerates to 373 km / h. And while the rapid monoplane flying weight of just 322 kg, it is equipped with private spacious cabin, retractable three-wheeled landing gear, flaps, full set of flight and navigation equipment.Ridiculously small, fuel consumption - 26.5 liters per hour of flight at cruising speed of 368.5 km / h. Aerodynamics, thanks to which DB-5 got so amazing speed and efficiency, not the first time amazing professionals and amateurs. In 1910 the pilot and designer Edward Nieuport aircraft then struck the world with their airplanes with the faint 20-hp motor. Has a top speed over 80 km / h, streamlined, "licked" "Nieuport" became a favorite of air races in Reims. After twenty years - is the next sensation. A passenger plane "Orion" firm Lockheed was the fastest combat aircraft of its time. In the late 30's - early 40's aerodynamic perfection famous bombers SB (USSR) and the "Mosquito" (England) has allowed these machines to fly faster than the enemy fighters.

Like any precision instrument, aerodynamics is omnipotent only in the hands of a master. Caring for agility aircraft, "licking" his design, not long to forget about the technological machine. Every student of aeronautical university knows that the best aerodynamic properties has a wing in the form of an elongated ellipse. It is also the most uncomfortable in the manufacture, and therefore expensive. The simple truth is: the smaller the wing, the less it feels the resistance of air. But, fly, you need to sit down and lower the landing speed, the better aircraft. So where is the "golden mean" - the optimum wing area, enabling fast flight and soft landing?

"Micro" did not emerge immediately and not suddenly. In 1967, Bede has built single-engine plane for a single non-stop flight (no topping!) Around the globe. Two years later the designer set three world records for flight duration: the car stayed on the air for more than 70 hours before the problem started in the electrical system. Externally, BD-2 - the so-called plane - looked like a glider with a wing of large aspect ratio. Flight experiments have shown: excellent aerodynamics allow the car with a 20-horsepower engine to keep quite a decent speed of 250 km / h. DB-2 was built in a classic case: pull the propeller, the engine in the nose of the aircraft. DB-5 looks different - the screw is installed on the tail and the motor hidden in the fuselage behind the cockpit.

Trace, even approximately, the course designer thought be planning a new car.

Thus, DB-5 - an ultra-light sport aircraft designed for professional pilots and pilots-lovers of any skill level. And those and others interested in the high-flying property, but it is important to give fans an excellent overview and make the machine easy to operate. However, even an experienced pilot would prefer such an aircraft "blind". And what prevents the review? Battened down during landing nose and the engine in front cabin. Solution, it would seem, is simple: to "cleanse" the nose of the engine, move the cabin for a seat, "engine" located behind the pilot, in short, swap them. Alas, the sum after this change of terms does not remain constant!

As for the engine, then he's all right - it's in the middle of the fuselage near the center of gravity.Much worse with a propeller. Imagine: the propeller rotational axis which coincides with the output shaft of the engine, stuck to the tail of the car and think for, in what must become stilts chassis to the blades not touch the ground. Make a correction to the scoring of the nose (and, hence, lowering the tail) during takeoff and landing. Clearly, if one can make such tsaplepodobnye "feet", then they will weigh more than the plane itself!                             

So what's really going on heavier gear or leave it in place? Need brilliantly coped with this task.With the courage inherent in most uninitiated novice than discerning engineer, he puts the screws are much higher than the engine and connects to an ordinary V-belt drive! Pulleys and a belt - they were afraid even during the infancy of aviation, preferring chains and gears.

To summarize. The engine is located in an ideal location for the alignment. Pusher propeller working in better conditions than the pull - does not waste power on useless blasting fuselage.Since the propeller is raised above the longitudinal axis of the aircraft, there is no need in high gear. Its easy to do three-wheeled, with the nose strut. Due 6lagopriyatnoy alignment (all the most massive machines - near the center of gravity) can do little control surfaces with a short arm from the center of gravity of the aircraft. The fuselage is shortened, the pilot does not need to make strenuous efforts to control levers. Compact case is more severe and durable. In general, the saving in weight, and hence in the cost of construction machines.

Successful scheme gives a lot of other advantages. Low light chassis easily removed by hand. On conventional aircraft weight retractable landing gear actuators reaches 3 - 5% of the flying weight machine. "Landing" "Micro", a low position of its center of gravity have reduced gauge chassis and remove the rack is not in the wing and the fuselage. Freed butt of the wing fuel tanks were.Ease of operation made it possible to shorten the lever and place it not in the center of the cabin, and the sidebar on the right hand of the pilot.

At the request of the purchaser provided "Micro" with wings of different extensions - BD-5A with a wing of normal length (speed version) and the BD-5B with a long, like a glider wing (cost option). Miscellaneous and engines. The range - three models of the West German engine "Hirt" capacity of 40, 55 and 70 hp

For lovers of special thrill in store Bede another novelty - the BD-5 "Jet" with a jet engine. The rate of this unique machine length 3.65 m is about 450 km / h. 

Proposing a "designer" for adults, James Bede and his firm complied with the rules of fair play: build an airplane should be feasible in the slightest degree experienced samodelschikam and occupy no more than 500 hours. Each billet carefully marked, equipped with detailed drawings at 1:1, and extensive guidance on handling and assembly. Brochures containing of operational leadership with accurate references to the necessary tools are made clearly and carefully.

As simple and relatively cheap exploitation of the collected aircraft. Taking into account depreciation, cost of maintenance, preventive maintenance, fuel, flight "Micro" for a short distance (San Francisco - Las Vegas) took 2.3 hours, costs $ 8 to 40 for the liner Boeing-747, 31 - for light-engine Cessna, 34 - for a bus, 51 - for car and 16 - for a motorcycle.

Long flight (to Los Angeles - Chicago) costs $ 36 against 201 for the car and 126 for the Boeing 747 ...

By early 1973 the company "Bede Corporation received more than 4 thousand orders for semi-finished kits BD-5 - a program which would be the envy many venerable aircraft construction enterprises.

MAIN DATA DB-5B (70 hp)

Length ................................................. ................................. 4.06 m

Scope ................................................. ................................. 6,53 m

Wing Area ................................................ ..................... 4.4 m

Screw diameter ................................................ ...................... 1.12 m

Weight empty machine ............................................... ............ 174.6 kg

Takeoff Weight ................................................ ...................... 322 kg

Fuel tank capacity ............................................... .. 79.5 l

Maximum speed (sea level) ... ... ... ... ... ... .. 373.3 km / h

Cruising speed (2300 m) ... ... ... ....... ... .. 368.5 km / h

Rate of climb (sea level) ... ... ... ... ... .... ... .... 6,85 m / s

Fuel consumption (at 75% cruise power) .......... 26.5 l / h

Range (at 65% capacity) ........................................ 957 km

Takeoff / landing run ............................................... ............ more than 300 m

With scab Stalling ............................................... ............. 88.5 km / h

(With flaps fully released)

MAIN DATA DB-5 Jet

Engine ................................................. ........ TRS-18 , 1 * 91 kgs 

Length ................................................. ................................ 3.78 m

Scope ................................................. ............................... 5.18 m

Weight empty machine ............................................... ............ 193 kg

Takeoff Weight ................................................ ...................... 413 kg

Fuel tank capacity ............................................... .. 208 l

Maximum speed (sea level) ... ... ... ... ... ... .445 km / h

Stall speed ................................................ ........... 122 km / h

Takeoff run ................................................ ....................... 335 m

Path length ................................................ ...................... 244 m

Practical ceiling ................................................ ......... 8,235 m

Range (at 65% capacity) ........................................ 885 km

excerpt from the book "The plane with their hands"

VP Kondratyev, LF Yasnopolsky

... And then it appeared DB-5 - a small single-seater with two-cylinder two-stroke engine.

The plane had a short fuselage with cockpit glider type in which the pilot was placed in a half upright position. Pusher was a tail and connected to the motor with an elongated shaft and belt transmission. Subsequently developed a version of Bede and from jet engine with a thrust of about 90 kg. The aircraft was manufactured as a set of pieces, from which anyone could build an airplane. As assessed by the Americans themselves, this is the secret of the success of the machine. The fact that the American rules aircraft, manufactured in the form of billets, was not subject to certification, that is a comprehensive flight test. Every amateur who built the plane from the set, he performed his tests on a very simplified program and received a "certificate" - permission to fly as a pilot car. In this case, the plane was bad or good, except for the fan, built and operated the machine, no one knew.

The second contributing factor to the success of DB-5, - skillful, subtle and clever advertising.Unusual patterns and appearance of the aircraft allows it to advertise and how is the easiest, and as the most convenient, and as the most stable, and as the easiest to manage. Thanks to advertising machine even interested in the U.S. Air Force, will be using BD-5 jet options as a standard training aircraft. Since the aircraft was in flight-testing institute the U.S. Air Force, where he was first studied in detail in flight. Here and found out that he is not very stable and not so well managed, and simply dangerous, even for professionals. The test results were published, and the firm went bankrupt Bede.

The main reason for failure, apparently, lies in the complexity of piloting small aircraft, as we have said. In order for the reader to evaluate miniature DB-5, we present some of his data: the wingspan of different variants from 5.18 to 6.53 meters, takeoff weight of 250 to 450 kg, engine power from 32 to 70 liters. with.

Later Jim Bede has built several airplanes, including aerobatic DB-8, which will be discussed later. Success of these aircraft did not have long abandoned aircraft constructor, to establishing a pilot car. However, recently there have been reports that Bede is building a new one, this time jet, supersonic aircraft amateur ( BD -10).

Concluding the story of DB-5, it should be noted advantages pusher propeller. If a pusher propeller located behind a smooth streamlined fuselage and nacelles, both DB-5, and before the screw is not formed a strong zone of flow separation, as in "Don Quixote" or "Elf", the loss of traction may be small. On the other hand, if the propeller is not blowing the fuselage and wing of a turbulent, swirl, wind resistance of the aircraft high speed parameter can be lower. Therefore, the aircraft type DB-5 with a pusher propeller behind a smooth fuselage may have a higher top speed, a few playing in the takeoff and landing characteristics and rate of climb. According to approximate estimates on the aircraft type DB-5 win in the maximum speed can reach 5-10% and 15-20% of the loss of landing data.