The science and art of soaring has been exciting and inspiring its eager proponents and participants since the activity gained prominence in the early 1920’s. Since that period there have been remarkable advances in the design, construction and performance of gliders (also known as sailplanes) and in the understanding of the air currents which carry and maintain them aloft.
From the sports humble origins where gliders manufactured from wood and fabric were launched from hilltops and then proceeded downwards at an angle of descent marginally better than the slope of the hill; the modern sailplane has evolved to the point where glide angles in excess of 1: 60 or more have now been realised. That means for every meter loss in altitude the glider moves forward a remarkable 60 meters. With such capabilities, sailplanes have now flown in excess of 3,000 Km and risen to heights of just over 50,000 feet in the hands of experienced pilots using just the power of natural air currents alone. An environmentally friendly activity by any measure
The modern sailplane is generally constructed of composite materials which may include carbon fibre, glass fibre and kevlar. This gives them exceptional strength and durability. They are equipped with a range of sophisticated instruments and systems which assists pilots to control and navigate safely and to get the best performance out of their aircraft from the atmospheric conditions which may prevail at any one time.
Whilst soaring represents a pastime that is easily and readily accessible to all ages, the design of production manufactured gliders, predominately from East and West European manufacturers, have followed the long-accepted orthodoxy of three axis control. These control inputs require a combination of hand, and foot coordination.
Implicit in this is the need to have the physical capacity to utilise these two primary functions with the full range of movement that they require. Whilst various attempts have been made to modify gliders to cater for people with limited or no movement in their legs, the results have been mixed, carried out on a somewhat ad hoc basis, and in a relatively few number of cases. Whilst acknowledging the pioneering work carried out in this regard by a number of sailplane manufacturers, and individuals, the efforts and success of the Schleicher factory of Poppenhausen Germany, are noteworthy. With an ingenuity typical of their well-deserved and long established name in the design and manufacture of sailplanes, their engineers were fortunate enough to be able to integrate a simple, safe, and effective alternative to using foot / rudder inputs for yaw control into the control circuit.
Utilising a device designed by J. Fisher, an aircraft engineer from the UK, and being used to great effect at the special needs gliding facility at Portmoak in Scotland, this mechanism once installed permitted the hand operation of the rudder. Thereafter trainees and pilots with limited or no movement in their legs could now enjoy the freedom and the range of control necessary to fully experience the joy of soaring flight.