The World championship on the aerobatics, taken place in 1976 in Kiev, has come to the end with a convincing victory of the Soviet pilots acting by plane Jak-50. They showed high-speed pilotage, with the big radiuses, completely using the resolved flight zone in the size 800x1000x900 metres. And foreign sportsmen carried out figures on small speeds with small radiuses, in the limited space - "round a tail" as pilots spoke. Such not high-speed style has been recognised then more progressive. In this connection in our country have started working out of the new sports-flight plane which would meet time requirements. Necessary characteristics could be received, having lowered specific loading on a wing and having applied more bearing, so thicker, a wing profile. For Як-55 - such name was received by the new plane - specific loading on a wing has been defined in 50 kg/m2 (at Як-50 - 60 kg/m2) the new profile of a wing with relative thickness of 18 % against 9-14 % at predecessors is developed.