The data of flight polar was extracted thanks to the series of test flights of the AC-4C, onboard № 045, executed by Chad Moore (USA).

According to recommendation proposed by Dick Johnson, on the glider AC-4C had been established fairings in a place of fastening of a wing and fuselage. Such type of fairings are established practically on all gliders of the “AC” series.

Chad Moore published results of the tests in article: “Performance Testing of the Russia AC-4c Retractable”, printed in the American magazine “Soaring”, September, 2002.