Two prototype aircraft hybrids between an airplane and a helicopter were presented yesterday at the aviation festival organized in the village of Bohot, near Pleven town. The two aircraft have been designed by engineers from Varna and Pravets.  If the tests prove successful, serial production of the aircraft will be launched. Its basic price will be about 40,000 levs (approx. 20,000 euro). The flying machines take off like an airplane, but they can also hover in the air like a helicopter.