Investigation into the steering ability problems of compact hovercrafts

The present paper investigates the requirements and the turning ability problems of the hovercrafts characterized by compact dimensions (with small width, powerful engine and big propellers). These vehicles require a very accurate control system, to combine the command of turning or trim with the possibility of reversing the thrust. In this article we briefly describe compact hovercrafts and focus on the various systems projected to improve their turning ability. We give an account of the steps which led to achieve our technical solutions and show the various systems of passive control surfaces adopted: to verify the different assessed implementations, several on-field tests have been performed on two vehicles, the Hover4 and the Multipurpose Air Cushion Platform (MACP). Finally we illustrate the ultimate chosen version of the system, in particular we outline the positive effects of the adoption of an unusual axis of rotation used to solve the problems created by the vertical rudders, whose centre is higher than the barycentre of the vehicle.