An outline of Von Karman's method of computing the potential flow of airships in yaw by means of partially constant dipolar superposition on the axis of the body is followed by several considerations for beginning and end of the superposition. Then this method is improved by postulating a continuous, in part linearly variable dipolar superposition on the axis. The second main part of the report brings the calculation of the potential flow by means of sources and sinks, arranged on the surface of the airship body.

Wind-tunnel tests are described, in which the angle of attack of a wing model was suddenly increased (producing the effect of a vertical gust) and the resulting forces were measured. It was found that the maximum lift coefficient increases in proportion to the rate of increase in the angle of attack. This fact is important for the determination of the gust stresses of airplanes with low wing loading. The results of the calculation of the corrective factor are given for a high-performance glider and a light sport plane of conventional type.

In the case of seaplanes, the lack of elastic shock absorbers, the presence of which might be quite dangerous, especially in taking off, makes it necessary to give some consideration to the phenomenon of landing. Special consideration must be given the process of taking off, since even moderately rough water may develop rather large stresses. The purpose of this communication is to show what has been accomplished in Italy and other countries and to draw a few useful conclusions.

This report concerns the making and evaluation of a towing test of a seaplane float system. Some of the topics considered are: 1) the influence of the wing cell and power plant on the take-off performance; 2) the determination of the resistance curve for the take-off free to trim; 3) the resistance curves with elevator control (at fixed trims); 4) take-off time and take-off run.