Grigore Brişcu

Grigore Brişcu (1884, Bârlad - 1965, Bucharest) was a great Romanian engineer and inventor.

Having a real inclined towards engineering, he joined in 1903 the National School of Bridges and Roads in Bucharest and followed also some courses in Paris. At the same time he joined the Faculty of Law in Iaşi, where he earned a degree in legal sciences.

He published in "Car Magazine" no. 48 of December 15, 1909, p. 8 and no. 53 of 1910, p. 98 the study titled "Helicopters", which showed that the helicopters are "practical, economical, safe operation and will be used widely by the general public". He was the first engineer who in 1909 began experimenting with the cyclic variation of rotor blade pitch in order to ensure horizontal flight and stability and piloting helicopters. Even today, the automatic deviation device is still one of the most important helicopter systems.

Grigore Brişcu stands as one of the most important theorists of mechanical flight. He made an helicopter model he named "air-carriage" which had all the features of a helicopter-like flying-machine: horizontal, vertical and lateral movement and fixed-point landing. It was equipped with two coaxial propellers rotating in contrary directions, whose angle of incidence of the blades may vary during rotation, to gain ascension force and propulsion. The solution was experimented by French aviator Paul Cornu (1881-1963), who built a prototype with an Antoinett engine. The Brişcu rotary engine was patented by the Romanian Office for Inventions (patent no. 2323/2046 of 1912).

Grigore Brişcu's contributions to the study and development of mechanical flight earned him a place among the greatest Romanian inventors of the 20th century.

Gheorghe Botezatu

Gheorghe Botezatu, known as Dr. Georges A. de Bothezat (1893, Jassy, Romania - February 2, 1949, Dayton, USA), Romanian inventor, engineer and mathematician.


Gheorghe Botezatu was born in Iaşi, Romania 1883 or 1882. He studied in Iaşi, Petrograd and Sorbonne, Paris, and obtained here a PhD (Étude de la stabilité de l'aéroplane - 1911), first of its kind. He was an aeronautical engineer and mathematician, professor of the Petrograd Polytechnic Institute in the beginning of the WWI, worked for DEKA in Petrograd between 1916 and 1917 and next he stayed in Iaşi at the turn of 1918. In 1918 Botezatu wrote the letter and report "General Theory of the Screw" (air-screw i.e. propeller of an aircraft), after he wrote off to Subcommittee on Buildings, Laboratories and Equipments in Feb. 1919 and the US Army Air Corps awarded a contract in January 1921 to Dr. George de Bothezat and Ivan Jerome to develop a vertical flight machine.


The 1678 kg "X"-shaped structure supported a 8.1m diameter six-blade rotor at each end of the 9m arms. At the ends of the lateral arms, two small propellers with variable pitch were used for thrusting and yaw control. A small lifting rotor was also mounted above the 180HP Le Rhone radial engine (which it also cooled) at the junction of the frames, but was later removed as unnecessary. Each rotor had individual collective pitch control to produce differential thrust through vehicle inclination for translation. The aircraft weighed 1700 kg at take-off and made its first flight in October 1922. The engine was soon upgraded to a 220HP Bentley BR-2 rotary. About 100 flights were made by the end of 1923 at what would eventually be known as Wright Field near Dayton, Ohio, including one with three "passengers" hanging onto the airframe. Although the contract called for a 100m hover, the highest it ever reached was about 5m. After expending $200,000, de Bothezat demonstrated that his vehicle could be quite stable and that the practical helicopter was theoretically possible.


He studied Earth-Moon-Earth routes and made a large number of calculations on the likely trajectory variations. Subsequently, calculations of Botezatu were consulted in preparing the U.S. Apollo Space Research Program.

In 1936 Gheorghe Botezatu published a revolutionary book, Back to Newton: A Challenge to Einsteins Theory of Relativity - Critical Discussion of The Three Great Cognitive Issues: Infinity, Absolute Time, Absolute Motion, Including the Rigorous Proof of the Fallacy of Einstein's Theories of Relativity, in which de Bothezat explores even more fundamental issues as human cognition, rationalism versus realism, the meaning of number, infinity, continuity, and, of course, absolute time and motion. Only after eight chapters of rigorous discussion of these fundamental concepts does he turn his attention to the Special Theory of Relativity and the concept of ether. Waxing philosophical in the tradition of the Greeks and Poincaré, this book walks through the necessary steps to understand nature at a fundamental level. The discussion of how Einstein's ideas fail is almost a side benefit.