VERBESSERUNG DER FLUGEINGENSCHAFTEN IM LANDEANFLUG DURCH KOPPLUNG VON SPOILER UND HOEHENRUDERAUSSCHLAG.

The effects of the coupling of spoiler and elevator deflection on the behavior of airplanes (pitch, flight-path angle, speed) are presented whereby an intended delay of the spoiler displacement is included in the investigations. The coupling yields a considerable increase of the quasi-steady load factor DELTA n/ DELTA alpha //s//t//a//t, and is equivalent to an increase of 1T/// theta //2 with regard to the time history of psi and gamma . These two quantities normally fixed by the configuration are considered decisive factors for the longitudinal flying qualities, together with the undamped short period ffrequency omega //n//a. By applying the coupling, it is possible to control the coordination of omega //n//a and DELTA n/ DELTA alpha vehicle//s//t//a//t by varying DELTA n/ DELTA alpha vertical //s//t//a//t and keep it in a favorable region, particularly when omega //n//a is increased by means of a stability augmentation system. Due to an increase of DELTA n/ DELTA alpha vertical //s//t//a//t flight path response characteristics can be improved. This is especially important for the landing approach. Corresponding to the direct effect on lift caused the spoiler deflection, the method has also the character of a direct lift control. Furthermore, it is possible to eliminate the problem of ″speed instability″ .