C.Jerzy Polish Aircraft 1893-1939 (Putnam)
Bronislawski System Aircraft
In the years 1910-11 Boleslaw Bronislawski, a Polish doctor of science working in France, invented a new method of control for aircraft, called the Bronislawski stabilizing system, which was claimed not to infringe any Wright patents and to offer substantial advantages over the conventional concept. Concentrating mainly on the development and perfection of his novel control system, Bronislawski decided to test it first on existing aircraft rather than on a machine of his own design and selected Henri Farman biplanes for this purpose.
His first machine was a modification of the Farman lifting-tail biplane with front elevator. The aircraft was adapted to incorporate the early version of the Bronislawski stabilizing system, which consisted of five stabilizing planes on each side, and was successfully tested at Juvisy near Paris around the middle of 1911, the trials being conducted by the designer's brother, who helped generally to perfect the system. This aeroplane represented only the interim experimental medium intended to try out the overall feasibility of the idea and confirm findings of the theoretical research, its wings retaining the original ailerons as the secondary means of lateral control.
Bronislawski's second aircraft was a conversion of the Farman Racing Type of 1911 with a 50 hp Gnome seven-cylinder rotary engine and embodied the revised and improved Bronislawski stabilizing system, which incorporated only two stabilizing planes on each side. In view of the encouraging results with the earlier type, the later machine completely dispensed with ailerons, relying entirely on the new method of control. This Gnome-powered model, completed in the autumn of 1911, was displayed at the 1911 Exposition Aeronautique in Paris, featuring fabric covering over the extensions of the top wing, which were originally left uncovered. The machine was extensively tested in 1912 and in the autumn of that year was re-engined with the novel 65-70 hp Burlat eight-cylinder rotary air-cooled engine.
The Bronislawski stabilizing system could be used not only on biplanes but on aircraft of all types and configurations, and in 1912 a special company was formed for the promotion and production of aeroplanes with Bronislawski controls. However, the sponsors of the venture apparently failed to convince prospective customers of the advantages of the new system, and the interesting idea eventually vanished into obscurity.
As exemplified by the second aircraft, the Bronislawski stabilizing system consisted of a pair of cambered planes, each 1.5 m (4 ft 11 1/2 in) long and 0.45 m (1 ft 6 in) deep, which were set at a positive angle of incidence and rigidly mounted on a rotating vertical steel-tube mast supported from the front and rear spars of the top and bottom wings by skeleton extension pieces of oval steel tubing. One of these units was situated at the end of each outer wing bay.
In normal flight these supplementary planes were arranged in end-on aspect to the relative air flows, but as soon as the machine was tilted out of the horizontal in a lateral sense, these planes were rotated about their vertical axes by means of wires passing from the pilot's control lever to a drum attached to the bases of their respective masts. By their rotation, the planes became incident to the relative wing and thus lifted or depressed according to whether their incidence was positive or negative. Both sets of planes at either end of the main supporting surfaces worked in conjunction, thus forming a righting couple. One of the most important features of the system was that in the action of restoring balance the position of the centre of resistance of the machine as a whole was not altered, so that there was no need to bring the rudder into action.
Bronislawski stabilizing planes combined the functions of ailerons and elevator. The system was claimed to be very easy to operate and to make flying much simpler, the movements of the control lever being adapted to the instinctive reactions of the pilot's body to maintain balance.
L.Opdyke French Aeroplanes Before the Great War (Schiffer)
Deleted by request of (c)Schiffer Publishing
Flight, December 30, 1911.
PARIS AERO SHOW.
ON this stand was exhibited a Henry Farman biplane fitted with the new Bronislawski method of balancing. This system consists of a pair of cambered planes set at a positive angle of incidence and rigidly mounted to a vertical mast, which is supported from the main planes by a skeleton of steel tubing. One of these units is situated at each end of the cellule. In normal flight these supplementary planes are arranged in end-on aspect to the relative wind, but as soon as the machine is tilted out of the horizontal in a lateral sense these planes are rotated about their vertical axes by means of wires passing from the pilot's controlling lever to a drum attached to the bases of their respective masts. By their rotation, the planes become incident to the relative wind and thus lift or depress according to whether their incidence is positive or negative. Both systems of planes at either end of the main supporting surfaces work in conjunction, thus forming a righting couple. As one of the most important features of this system, the inventors claim that in the action of restoring balance the position of the centre of resistance of the machine as a whole is not altered, so that there is no necessity to bring the vertical rudder into action, and on this score they claim that the Wright patents are not infringed.