Józef Borzęcki was absorbed in the idea of building a simple, amateur glider for everyone. It was created under the influence of information about the pre-war Polish glider Bąk, designed by Adam Kocjan. His interest in aviation matters grew. He collected aerial books and magazines. He visited libraries and private collections. Despite many classes at work and family responsibilities, he devoted every spare moment to design work on his dream glider. Independently acquired the knowledge necessary to carry out the construction project.
During 1952–1961 Józef Borzęcki designed and built a motor glider called Stratus. He even built his own dyno to choose the right engine. He made this engine himself, based on a Czech circular saw engine. He designed and made the propeller himself, then he began making parts and assembling the airframe. He made all parts, from the smallest ones (e.g. he tapped several thousand rivets!) By himself. The construction of the powered sailplane was carried out in extremely difficult conditions – an apartment and a garage served as a workshop. The designer believed that all parts should be made perfectly, because flight safety depends on them. At the same time, he strived for its construction to be characterized by simplicity of operation and reliability of operation.
It was initially powered by an engine from a Czech chainsaw and wings from Żuraw (crane) glider. It initially featured classic flight control system with a control stick and rudder pedals, subsequently replaced by a “coupled” control system, designed by Borzęcki, in which the stick was used to control the aircraft in all axes (pitch, roll and yaw). It was aimed at facilitating flight training and increasing comfort in non-professional conditions.
The construction of the powered sailplane was completed in 1960 and J. Borzęcki began the first tests. During an attempt to take off, during Easter 1962, the wing was seriously damaged. Failures broke the constructor’s stubbornness. He no longer wanted to repair the glider, but he returned to work on it. He used in it (later used in all its constructions) so-called coupled control, i.e. only with a joystick that deflects the rudders and provides longitudinal and transverse control. Control of this kind, which he developed and developed completely independently, took him two years of hard work. Coupled control system of J. Borzecki’s idea had a number of advantages, especially significant in the case of little experience of amateur pilot. He again began the tests, which showed the correct flight properties of the powered sailplane. Over the next few months, he often performed test flights, which slowly turned into flying for pleasure. During 1961–66 the Stratus was flown illegally and in secrecy.
In July 1966, the designer invited the pilot of the flight and the editor of the newspaper Polish Word – editor Andrzej Macko to perform a test flight. He made several test flights, issuing a very favorable opinion about him. Articles by A. Macko published in Kulisach and the Polish Word about Józef Borzęcki’s motor glider started a nationwide discussion on amateur aviation in Poland.
In May 1967, an extensive article on amateur aviation was published in Winged Poland, a lot of space was devoted to the glider “Stratus”. In the press and everywhere where there were people interested in aviation, from aeroclubs to the Department of Aviation, there was a discussion about the future of amateur aviation in Poland.
In late 1960s the constructor undertook a rebuilding process. After this rebuilding the motor glider became the Altostratus.
