NACA-TN-1203

Abstract

INTRODUCTION <br>Analysis of accident data published by the Civil Aeronautics Administration have shown that stalls, with or without subsequent spins, are responsible for most of the fatalities and injuries in light-airplane accidents. In connection with flying-qualities tests of five light airplanes during 1939 and 1940, it was noted that certain stability and control characteristics of the light airplanes' might be modified to increase the safety of these airplanes, particularly with reference to stalling and spinning. <br>In 1940 and 1941 an investigation was made on a typical light airplane of a number of modifications intended to increase the safety of the airplane. The report on this invention was not completed at that time because of the urgency of the war work which the NACA was beginning to do. It is now being published as a part of the NACA Personal Aircraft Research Program in order to acquaint the manufacturers of personal aircraft with work the NACA has done in this field. One of the primary objects of the investigation was to reduce the difference between the up-elevator angles required to stall in the power-on and power-off conditions and then to limit the up-elevator deflection below that required to stall. It was hoped that under these conditions the airplane would continue in installed flight with the stick full back and the power on. To hold the changes to a minimum, to make them simple enough to be readily incorporated in airplanes now in service, and not basically to alter the appearance of the airplane were also objectives of the investigation.