Talk:Coandă-1910/Lsorin

The Coandă-1910 was the first jet-propelled aircraft, powered by a reactive propulsion unit consisting of a turbine driven from a conventional engine.

It was constructed by the Romanian inventor Henri Coandă working in France and exhibited at the Second International Aeronautical Exhibition in Paris around October 1910. The unconventional design was received with admiration and the opposite side with skepticism, as reflected in journals describing it as the attraction, "curiosite" or even "something of a freak" with special emphasis on the powerplant which was a questioned for the missing of the conventional propeller and its small size in comparison to its thrust. The plane was followed by several patents received in several countries regarding the powerplant and the airplane. Several tests did follow, which culminated according to later statements of Coanda with a short flight ending with a crash.

Post World War II, after the development turbojet, the first practical jet engines, Coanda declared that Coanda-1910 was in fact propelled, by the first jet engine with is described in today terms as termojet or motorjet, claim supported and debated since then.

Early developments leading to Coandă-1910
Coanda was interested in achieving reactive propelled flight already in 1905 in Bucharest, with tests with rockets from Army Arsenal attached to airplane models. At Spandau, Germany Coandă is testing successfully in secret a flying machine, with one traction propeller and two "gyroscopes", with Antoinette 50HP engine. According to later claims, Coandă has tested the machine at Cassel in front of Bernhard von Bülow. In that period he started to be interested in jet propulsion. According to Coandă the plane and a jet model provided with a 'turbo-propulseur' have been presented in December 1907 Berlin at the Sporthalle (indoor sports arena).

Coandă continues his studies at Liege, Belgium were he meets his future good friend Giovanni Battista Caproni. With the help of Gustave Eiffel and Paul Painleve is testing different wings configurations and air resistance on a platform build in front of a railway engine build by Eiffel. The results are used to build Coanda-Joachim glider with the help of a car manufacturer Joachim. In presence of his friend Giani Caproni the glider is flown at Spa-Malchamps,Belgium.

Construction, exhibition and tests in 1910
With the opening of the École nationale supérieure de l'aéronautique et de l'espace on 15 November 1909, Coandă moves to Paris on Rue de Ranelagh. In a little atelier, in the court yard of his house starts to build his sesquiplane and the unusual powerplant helped by his school friend Cammarotta-Adorno. He starts testing the thrust of the combined mechanism of the future powerplant, on a dynamometer in his workshop, which is described in detail in April 1910 La Technique Aéronautique magazine. During whole year Coanda applies several patents regarding the parts of airplane and the engine assembly. The plane is presented at 2e Exposition de la Locomotion Aérienne at Grand Palais in Paris. Placed on the second floor next to Hydravion, the first floatplane it was definitely one of the planes to raised a lot of questions.

The aircraft cell was a novelty for the time, on a steel frame and covered with molded plywood refinished with reddish-brown color, instead of the doped fabric generally used. The monocoque wings which featured the first thick airfoils, were held in place by tubular steel struts without any bracing from flying wires. A small horizontal stabilizer was placed under the rear fuselage which was terminated by a empennage arranged as a Saint-Andre cross, used for pitch and direction control. The four ruddervators terminating the tail were controlled with the help of two wheels placed on each side of the open double seat cockpit, system already featured on Antoinette VII airplane.

The most discussed feature of the airplane, as presented, was the powerplant. It featured an 50 hp Clerget in-line water cooled reciprocating engine placed in front section of the fuselage and used to turn the compressor, already patented earlier that year, through a 1:4 gearing mounted upside down. The compressor with a diameter of 50cm is placed in front of the cowling placed before the fuselage. The water radiators are placed inside the cowling on top of the fuselage. Waterlines together with the insulated exhaust pipes from the Clerget run trough the fuselage. The exhaust gases are injected in the distributor part of the turbine, to form what is it today know as a turbocharger. Prior to injection in the distributor the exhaust pipes are run around the cooling water lines in order to prevent the excessive fall in temperature before their utilization and around a "heat-exchanger" enclosing the air jet conduits. The "turbo-propulseur" as Coanda call it in the exhibition leaflet, was capable of generating of 220 kilograms-force (2,157 N; 485 lbf) of thrust. The powerplant was referred in the epoch press with different terms: a turbine without propellers, turbo-propulseur or a suction turbine. It is not clear, if for the exposed model, the compressor had provision for the introduction or combustion of fuel or not, as it was not stated in the earlier patent. Later several experts conclude that it would not be possible for the powerplant as described in the leaflet, to generate the listed trust, without extra injection and combustion of gas as the jets would leave the diffusers. Coanda later claimed that such a system existed, but no patent claim was made for it. The engine was noted in some magazines as being "of remarkably small proportions in relation to the size of the machine." and "claimed to give an enormous wind velocity", but that the intake area seemed too small to produce the stated thrust, and that "it also appears as if enormous power would be necessary to drive it", more than supplied by the Clerget.

After the exhibition the plane is moved to a Clément-Bayard workshop at Issy-les-Moulineaux were a series of trials on the engine and airplane are started. This work is reflected by addition to the powerplant related patents. According to later statements of Coanda in 50's, he did take-off and crashed the plane on 16'th of December only in presence of his mechanics.

Rebuttals
Several historians and highly regarded specialists have questioned the proofs used by Coandă and his supporters for demonstrating that Coandă-1910 was propelled by a jet-engine and that it really did take-off and crashed during test trials in December 1910.

Engine
Around the 1950's when the jet engine proved to be the best solution for high altitude, high velocities, much better weight/thrust ratio with a much more simple construction, it became clearly the right choice for many application in aeronautics. The industry changed focus from the previous solutions (reciprocal engines, rocket engines etc) to jet engines and in depth studies where started into the topic. As well Coanda was already a respected scientist dealing with high speed fluid and the physics of fluid jets. This raised the attention on Coandă's current and previous work. Special attention was started to be given to the Coandă-1910's powerplant. For instance January 1952, a letter by J. Billings arises the awareness of Coandă-1910 to the Flight magazine readers. Several years later, basically two groups of scientists are formed with regards of the engine classification:
 * the engine was merely a ducted fan
 * the engine was a primitive type of jet engine

Ducted fan
In March 1952, Flight published a reply to earlier J. Billings question. In that letter John W. Lane explains that a study if the English Patent of the "turbine" reminded him of the Campini's arrangement, "but whereas Campini added a combustible medium to the compressed fluid and ignited the mixture in a combustion chamber, Coanda utilized the reciprocating engine exhaust gases by conducting them from a semi-spherical collection chamber...". He later points out the Coanda "missed inventing the aircraft gas-turbine by not thinking to inject a fuel into the discharge airflow from his "propeller" and burning the mixture in a combustion chamber prior to its ejection" and tries to give a "concise description" of Coandă's invention. Later Charles Harvard Gibbs-Smith, aviation historian at the Science Museum in London, joined the discussions in Flight pointing out that T.R.Servian is wrong in his earlier letter and needs find more references in his 1960 first book about the early aviators. Gibbs-Smith describes the powerplant as "a 50-h.p.Clerget engine driving a 'turbo-propulseur' in the form of a large but simple ducted air fan. This fan was fitted right across the machine's nose and the cowling covered the nose and part of the engine: the resulting 'jet' of plain air was to propel the aeroplane."

Early jet engine
When at the end of 1950's, Coandă started to be asked more about the details of his Coandă-1910 and especially the thrust information of his powerplant, he declared that after the Paris Aero Salon he did several modifications to the engine and tests which ended with a short take-off and crash of the plane. In one of such test he added two asbestos plates inside the cowling to be used as well as deflectors of the flames generated in the burners away from the wooden fuselage. One such later additions to the powerplant was the 3 December 1910 claim for patent.

Later claims
Years later, after the development of the jet engine, Coanda started making claims to the effect that his 1910 aircraft was actually a motorjet and that he had actually flown it himself.

By the date (either Dec 10 or Dec 16 in various stories) given by Coanda for his claimed test-flight of this aircraft, it had been sold it to a Mr. Weyman - some time before October 29, 1910. The Aeronautical Journal wrote "There is a wholly new description of the inner workings of the machine that does not occur in any of the accounts given above and which defies all the patent specifications." Coanda told various contradictory stories about his claimed 1910 flight, and produced a set of altered drawings which he falsely asserted were proof of his claims : "The differences between this version of Coanda's story and his earlier are marked and hardly need to be pointed out; though the obvious ones are; the planned verses the completely unintentional and accidental flight; the immediate flight verses the busy taxying about the field; Coanda being thrown from the plane after it stalled verses Coanda pitched forward after landing, and so on. Apart from his personal recollections, Henri Coanda also bestowed upon the museum some drawings and illustrations of his turbo-propulseur. The drawings, purporting to show internal of the machine, are unfortunately modern. That is to say, they were obviously executed in the 1960s, not in 1910 or 1911; worse, the fuel injection outlet tubes into the aft end of the turbine seems to be an even later addition to the original drawings. In brief, the drawings by themselves do not constitute evidence in Coanda's claim."

The original patent and story of the aircraft are presented at Le Bourget Air and Space Museum,. G. Harry Stine, a rocket scientist, a prolific author of science fiction, aviation and science history books and "the father of american model rocketry", who worked with Coanda and studied his inventions for years stated in his book The hopeful future, that "there were several jet-propelled aircraft in existence at an early time-the Coanda-1910 jet and the 1938 Caproni-Campini Nr.1, the pure jet aircraft flight was made in Germany in 1938".

Some of Coanda's supporters admit that his plane was shown at the Paris air show in 1910 as a ducted fan craft, but claim that when testing showed that it was incapable of flight he modified it into a motorjet and flew it on December 16, 1910 (or in some versions December 10). Coanda was still filing Patents on a turbopropulseur in May 1911, and still making no claims about fuel injection, or combustion. However, most of the aeronautics and astronautics scientific community agree that the Coanda-1910 was the world's first jet aircraft. At the Seventeenth History Symposium of the International Academy of Astronautics, Budapest, Hungary, 1983, it was said that Coanda-1910 was the first reactive aircraft, and at the twenty-fourth Symposium of the International Academy of Astronautics, Dresden, Germany, 1990, it was again stated that Coanda-1910 was the first jet aircraft.

Coanda linked the 1910 aircraft with the discovery of the important aerodymanic effect that bears his name. Coanda claimed he was able to observe that the burning gases from the engine hugged the sides of the aircraft very closely and this is what seemed to cause the fire he mentioned in his story. These claims were not made until sometime later.

Coandă did further development on his turbo-propulseur. During World War II he was given a contract by the Germans to develop a propulsion system for ambulance snow sleds for military use.