It is neither a glider nor a sailplane. Here you see future Experimental Flapping Wing Aircraft, EFWA, which will fly like a bird, flapping with its wings! No airscrew (and therefore no noise, except of muffled exhaust of relatively low-powered motor), highest efficiency and maneuverability, new discoveries and sensations of the flight with obedient non-fixed “live” wings. The start point of the new trend in aviation and aerodynamics. The new on principle class of aircraft, in addition to the existing ones – planes and copters. The first in the world.

EFWA will be created on a base of a usual motorless up-to-date high Q 2-seat glider (e. g. German DG-505 Elan, Grob G-103 Twin Acro II or similar). The creation is approximately on 70% an assembly of standard ready parts: basic glider, suitable motor of any destination, hydraulic system parts etc. Only wings and centerplane are to be altered. That is why the creating will be very cheap, by aviation measures. Nevertheless, it requires advanced technology and therefore can be made by experienced manufacturer only.

This aircraft (the name is to be invented too) is designed exclusively for demonstration of human flapping bird-like flight, which seemed an unattainable dream so long, as well as for acquisition of the patents, prizes etc. Indepent takeoff and taxiing provided.

In the future flapping wing aircraft can be used as a light, ecological friendly, noiseless and economical, “stealth” aircraft for many purposes (patrolling, reconnaissance etc.), as well as for sports, amateur flying and so on. The prospective is great: since men like to fly by planes and gliders, they surely will adopt future flapping wing aircraft.

The author of the EFWA project – Boris M. Doukarevitch – is the only owner of the unique “know how”, which comprises all the necessary information: the detail description of principles and of the exemplary construction, methods of tests, pilots training etc;. Do you want to know a bit more about this unique project? See below.

Surely you know the glider of Lilienthal, plane "Flyer" of Wright brothers, copter of Igor Sikorsky. Maybe, the future first-in-the-world flapping wing aircraft will be of your name?

• Question: What are you talking about? Aviation exists more than 100 years. Maybe some unknown fields left, but - "new possible TYPE of aircraft"! It is much more, real "terra incognita" and it is still unknown? whether it is possible in our advanced times?

Answer: I have to say YES. Let us make a simplest classification of the types of aircraft. Any aircraft needs lift and propelling force at the same time to fly. If an aircraft uses wings to obtain lift force and airscrew (jet) to obtain propelling one - what type is it? No doubt, it is PLANE. If the same airscrew (rotor) is used to produce both lift and propelling forces - what is it? Sure, COPTER. And if an aircraft uses the same wings to produce both lift and propelling forces LIKE A BIRD - what is it? It is FLAPPING WING AIRCRAFT (FWA), the last member of the "classic" aircraft family, still unborn "junior brother" of plane and copter. Manned motor FWA does not exist now and never existed (flown), trust me or verify. So the whole class (type) of aircraft is really absent now! The mankind already visited the Moon, but still cannot create an aircraft flying like a usual bird, which everybody can see at any courtyard. Such is an interesting paradox in our really advanced times.

• Who are you?

I am engineer, live in Moscow, Russia, my name Boris M. Doukarevitch. I designed a project of motor manned Experimental FWA, EFWA. Now I am looking for ways of embodiment.

• Let birds flap with their wings if they want. We will fly by fixed-wing gliders, planes, as well as copters, and it is quite enough. We built these aircraft and our labors must not be in vain. Besides, there is much work to be done.

Congratulations. Perhaps, you are a happy man (woman): you do just what you like to do and want nothing more. Continue and enjoy this happy life. I ought to notice only, that creation of the first-in-the-world EFWA - it is progress with use of all accumulated aviation experience. In the future will be no opposition and even competition between FWA and existing aircraft, because each member of this family of aircraft has its own destination, merits and demerits.

• Hmmm…. I remember something. Web-winged, pterosaur like, awkward-looking experimental aircraft or scale models… Were all attempts of FWA creation unsuccessful indeed? Why?

Yes - all attempts to create manned motor FWA were unsuccessful (I do not speak about man-powered ones, which were, and are, full absurd, "for the birds"). Why? In general, it was too early. Progress moves from simple to complex, so the mankind learned first to create fixed-wing aircraft, planes, since they are simpler than future flapping-wing ones. However, nowadays planes (and especially gliders-sailplanes, where you cannot rely upon life-giving power of motor) became utmost perfect. It is time to go further. Whether the mankind will ever helplessly watch only over birds?

About scale models with flapping wings - yes, they are well-known and really fly during more than 100 years. It is possible to buy such a model as a toy for children. Unfortunately, these models fly by itself, we still cannot control their flight (I mean - operation of their flapping wings), so it is of no value.

• OK, maybe FWA will really appear in the future. What it will look like? Web-winged like a bat or feathered like a bird?

Not at all. Is a modern glider web-winged or feathered? No. Like this, future EFWA will be very much similar (in motionless state) to a usual modern high-ratio glider, - see the figure above. An experienced eye only can catch the differences: oversized "ailerons", visible butts between wings and centerplane which indicate possible mobility of wings. You can see also inlets for cooling air, which allow to expect that there is a motor behind the pilot's cabin.

In state of motion: naturally, EFWA will flap (wave, swing) with its wings. Flapping frequency will be very low, in the range of 0 to ca. 1.5 Hz. All flight will be in silence, except of soft muffled exhaust of relatively low-powered motor. Not more noise than that of VIP Mersedes.

• Sounds good. However, I do not believe that such an evident, ordinary-looking vehicle - like a usual glider - was not invented and built before. What were the reasons? Can you explain in details?

Yes, of course. I learned many FWA projects. There are two main faults.

Firstly - most of designers paid no attention whether their projects are perfect from the point of view of usual, fixed-wing aerodynamics and experience. Moreover, the said designers did not strive to! It is mere ignorance: you cannot master algebra unless you know count. To make sure, see, for example, American patent 3.498.574 of Mar. 3, 1970, author A. Ernst. The construction looks very obsolete: bad structure, bad aerodynamic forms, bad control of attitude and low gliding ratio… Meantime, in 1970 planes and gliders were already quite perfect .

Secondly. The next flaw is much more serious. It is enough to watch for a flight of any great bird to notice how highly variable and extremely expedient wings movements are! Meantime, as far as I know, practically in all FWA projects flapping wings are connected immediately with the motor via reducing and performing gear. Some authors used rather complex paths of wing movements - like the figure "8" or other closed curve. The reason? "It is necessary to do so, according to my calculations". The result: an aircraft flaps with its wings with aggrieving monotony, like a windmill, and so is not able to takeoff and fly. Control over flapping wings must be not worse than that of live being - optimum, self-adjusting and complete.

I know only one patent of a motor FWA with relatively good control over flapping wings - it is the said American patent mentioned above! Unfortunately, there are other great flaws which depreciate all the project…

I will not examine here other typical flaws of existing FWA projects, since these flaws are relatively not so serious. Unfortunately, even small missed flaw is able to kill the whole design.

• And how did you overcome these flaws in your project? What is your main idea?

There are two main ideas.

Firstly. As you can see on the figure, the EFWA looks like an up-to-date glider: it has perfect aerodynamic forms. Moreover: it will be built on a base of a usual modern 2-seat motorless glider, e. g. German DG 505, Grob G-103 Twin Acro II or similar one. Transformation from a glider into the EFWA comprises rewinging, installation of new control system and a powerplant into the room of the second (rear) cabin instead of pilot's seat etc. It is very important to retain (at least, do not worsen too much) conventional properties, geometry and MTOW: the first EFWA must glide with fixed wings not worse (as much as it possible) than the basic glider. It is the half of the future success and a guarantee of pilot's safety, in addition. Watch for flight of a sea-gull and you comprehend: easy and perfect flapping flight is possible only if perfect gliding already mastered.

Secondly. Control over flapping wing - it is the main, most important problem. So the main idea lies here. It is utmost simple; however, to make it comprehensible, I have to mention the experience of brothers Wright

During creation of the first-in-the-world plane they had run against the analogous problem: how to control over flight (in that case - over attitude)? Nowadays all is clear for everybody, but a century ago two different approaches existed. The first one: plane must carry a pilot like train carries a passenger, i, e, with no interference of the latter, plane must fly by itself. The second: it is impossible to create plane which is able to fly by itself, that is why it is necessary to assume a risk and to entrust a pilot with direct control, in spite of the fact that nobody could guarantee that a man is able to control over flight, since no man has flown before. (Except by balloons, but there is another approach.) Wright brothers did it: they rejected "control machines" and entrusted a pilot with direct by-hand control. It was very natural, bold and only right solution, though, maybe, forced and instinctive one.

Now, 100 years after Wrights, the problem of control (in the case - over flapping wings) arose again. The history repeats! Now it is impossible again to create a "wise" and perfect "flapping robot" due, at least, to absence of the trustworthy and proven theory of flapping wing work. And again, as mentioned above, practically all FWA designers are still trying to create such a "flapping robot". But this way does not lead to success. That is why I see only one real and reliable way of solving the problem: to entrust a pilot with manual, direct, immediate control over flapping wings! (In fact, it is repetition of brothers Wright experience on the higher level.) Let him operate flapping wings as well as ailerons, rudder and elevator! A man-pilot is a very perfect creature and does not yield to any flying being; in process of safe training he will certainly find (determine, feel, elaborate) the way of flapping which gives maximum effect under the concrete given conditions.

But! It is easy to operate rudder and elevator of a light glider, and what about handling of long, heavy flapping wings? They transfer power which is necessary for flight, at least up to several HPs, which is certainly exceeds abilities of any man. The solution is evident - it is necessary to use well-known hydraulic boosters which reduce efforts on the joysticks but retain feedback etc. A hydraulic pump driven with a motor supplies the energy for the said boosters (and therefore for wings and for flight as a whole), while the control depends exclusively on a pilot.

The similar way of control is used in the American patent mentioned above. It fits mainly for the first concept experimental aircraft, which is the subject now.

• The future FWA will be too complex and expensive…. Hydraulics, motor in the limited inner room of a usual glider.. Is this work feasible for homebuiders or small manufacturing company?

Surely, future motor FWA will be more complex than its predecessor - motorless glider. This is inevitable payment for freedom, for the possibility of independent takeoff and active flight, as well as for establishing of the new class of aircraft. However, it is not so awful and expensive.

Let me remind once again that the very first EFWA will be created on a base of a usual glider; in fact, it will be a kind of glider conversion or remake. That is why creation will be approximately on 70% not more than mere assembly of standard ready-made parts: basic glider, suitable motor of any destination, ready-made hydraulic system parts from fighter or bomber etc. Wings and centerplane only are to be altered. About hydraulics - is it so awful while any usual car has it? The manufacturing will be many times cheaper than building from zero level, I daresay - will be very cheap, by aviation measures.

Please note also, that EFWA will be exclusively experimental, concept vehicle, belonging to no one of existing aircraft class! So it will be utmost "wild" machine, with no certifications, documentation, standard tests and so forth. All this greatly facilitates manufacturing and reduces the expenses too. It is necessary to make only one (1) flying sample, designed only for investigations and for limited number of simple demo flights with no overloads etc. - like the first plane of Wright brothers at the happy childhood of aviation! So, though the manufacturing requires high technology, it can be fulfilled by a little company experienced in building of up-to-date (motor)gliders or even by qualified homebuilders. In fact, brothers Wright were talented and bold Homebuilders too! And it was quite enough.

You will see only one real wonder: a great white "glider" suddenly started to flap slowly with its wings and climb! By the way, I am not sure whether an independent takeoff will be provided from the very start. "Flyer" of brothers Wright had no independent takeoff either! Nevertheless, the devices for such a takeoff are known and can be included into the structure of the EFWA from the very beginning, if needed.

• Well, what will be further?

Prospective is very great, though a bit vague now. No wonder: who dares to predict the future of the child who is yet be born? However, I foresee the following:

• FWA will be first-in-the-world almost noiseless motor aircraft. The problem of excessive noise is very disturbing for aviation. This is the first chance to get rid of noise.
• FWA will be utmost useful and irreplaceable "test bench" for practical investigation of flapping flight and of operation of flapping wings. It will give utmost valuable data which is impossible to obtain by any other way - neither by observations over flying beings nor by scale or any other possible modeling. Using these data as a basis, scientists will be able to start creation of the new aerodynamic theory of non-fixed wing. Existing fixed-wing aerodynamics will enter into this new general theory as a simple particular case, for zero wing flapping frequency.
• according to theory of great Russian scientist N. E. Zhukovsky, FWA will be utmost economical aircraft, since flapping wings throw off maximum mass of air at minimum velocity by comparison with a rotor or airscrew.
• FWA will present greatest interest for leisure and sport. Fillings and expressions of FWA pilot, who completely masters over flapping wings, will be much more deep, various and bright than these of plane or glider one, who is occupied with support and control of aircraft attitude only. (It means, by the way, that FWA immediately may become an profitable consumer article. The first flying sample may cost big money afterwards as a unique museum exhibit.) Perhaps, possession of flapping wings will greatly enhance maneuverability, as well as takeoff and landing parameters. Maybe, new kinds of air competitions will appear - for best beauty and perfection of flight, a kind of air slalom…

A bit later, some years after, FWA will be more or less mastered, and I foresee new possibilities for:

• Automation and computerization of flapping wing control, which will liberate a pilot from routine monotonous work - a kind of flapping-flight autopilot.
• New methods of control, e. g. with use of biocurrents instead of joy-sticks.
• Creation of hybrid flying vehicles. Such an aircraft will have both propeller (for long-term uniform fixed-wing flight) and flapping wings for maneuvers, improvement of takeoff and landing, for noise reduction etc., with turned off or removed propeller.) This will be wonderful universal light aircraft - a plane, glider and FWA at once!

However, it is the very beginning of the long way of the new aircraft type.

• OK, all this is very interesting, but what do you want? Should you are so clever, why do not you build your EFWA yourself? You disturb busy men instead - what for?

A good question. Of course, any inventor ought to keep his mouth shut until he showed to respected public something real, i. e. material. Unfortunately, I do bother busy men - why? Because the situation changed in comparison with Wright brothers times. They built the first fixed-wing plane really from zero level and bothered nobody. However, creation of the first EFWA must start from level of a perfect glider, which wants advanced, high technology. A great volume of aviation experience accumulated here, obtained by hard labors. So, if you want to create the EFWA, you must "stand on shoulders of giants" (a phrase of Sir Isaac Newton), - i. e. men experienced in manufacturing of up-to-date high-ratio gliders-sailplanes, or to be such a giant indeed. I am sorry to confess that I am not such a giant. That is why I am looking for, figuratively speaking, "the second brother Wright", a connoisseur of gliders. Otherwise the good idea may be lost, which is not good.

• Well, you are right: nobody in the world had created successful FWA, - unfortunately, including me! So, though I am an experienced aviation engineer, how can I judge, whether your project is good or bad, feasible or not, is it expedient to spend time and money on? Give me a lead, a compass!

A good question too. As stated above, future EFWA will be "the junior brother" of existing planes and gliders, the member of the same family. It means that in the EFWA project all the existing principles of aviation design must be observed! (Exept one obsolete and false principle: "Wings of an aircraft must remain fixed forever".) So try to find in my project any violation of principles you know very well, try "to smell a rat". Should you find no contradiction to the existing aviation experience, you must consider the project as being viable and feasible. This is a kind of the "presumption of innocence".

• It is too risky adventure, too unusual one.

It is a statement, not a question, but - a very sober thought. You know best about your own affairs! You are free person! Nobody in the world can make you - like as nobody made brothers Wright quit profitable and accustomed business (repair of bikes) and start creation of unbelievable, unseen before winged vehicle. First-in-the-world innovation - it is utmost special business; fortunately, extremely rare one. Since your innovation has no analogs and nobody knows about it, nobody wants it. No experienced experts exist, and nobody will advise, support and approve you. On the contrary, the whole world will oppose you! On the other side, the fame of discoverer is utmost valuable, should it is of interest for you… So think twice before you decide to start creation of the EFWA.

• What does your project look like? Is it more than a mere idea?

Surely yes. However, there is the particularity.

As it was stated above many times, the first EFWA must be built on a base of a usual glider. The model and structure of the glider can vary, - which one is available. That is why my project can be only exemplary one, "know how", if you will. Nevertheless, the project comprises all necessary information about the structure, testing, training of pilots, stages of implementation and so on. It enables to start creation immediately.

• Who can build the first EFWA - in cooperation with you?

I guess, it may be a small aviation manufacturing company, experienced in building of modern (motor)gliders, or even a group of qualified homebuilders. The main, most important term - ambition, longing to be famous, to seize own position in aviation. Large, advanced, well-known companies as a rule are very conservative, awkward and supercilious, so I doubt that cooperation with them is possible.

• Is it of interest for a manufacturer to embody someone else - your - project?

For manufacturer it will not be "someone else" project, since this manufacturer will be considered as the author of the future patent, enjoying all rights. It is fair play, since a great amount of creative work is to be done. I surely will not be an only author of the real flying sample.

• How can I get more info about the project? All this wants pondering.

Contact me with no hesitation.

Asked and answered - Boris M. Doukarevitch, Eng.

Address: To be called for B. M. Doukarevitch, Main Post Office, Moscow Center, 101000, Russia.

Phone: (7 095) 421 0044

Email: doukarevitchb@mail.ru , bmdouk@chat.ru

Feb 2002, Moscow.