A deltaplane, or by the passionate simply called “wing” or hang-glider, but more precisely ‘Rogallo Wing’ (the name derives from its inventor) is today an instrument designed for the ‘free flight’ such as hang-gliding and paragliding (more precisely for the ‘recreational or sport flight’) and enables an activity which stands exactly between the “recreational or sports flight”. The deltaplane is the only aircraft that is generally steered through the mere shift of weight by the pilot, with only very few exceptions of deltaplanes with aerodynamic commands. Due to its low acquisition, use and maintenance costs, the deltaplane has been the instrument that opened the doors to many flight enthusiasts who otherwise would have not been able to experience such a fascinating adventure.
After the appearance of the paraglider – which is even less complicated and bulky – the number of amateur hang-gliders, or deltaplane pilots has significantly declined, resulting for the activity to become a competitive discipline, favoured by the higher performances of the deltaplane itself. The deltaplane has a structure made out of tubes, cables, canvas, bolts and nuts, specifically designed and arranged to enable the vehicle and the pilot to fly in very specific weather conditions, while guaranteeing a high mechanical reliability. A deltaplane is essentially a pair of half-wings kept open and horizontal by two “counter-tethers”, one upper and one lower. The upper counter-tether is sustained by the tower (or master) whereas the lower one is sustained (during the flight) by the trapeze and inside there is space for the pilot. The main structural particularity of the deltaplane is the twist which has a considerable importance in guaranteeing the stability of the flight.
The twist – which is measured in angular grades – is the difference between the inclinations of the wing rope in the central section compared to the wing rope at the extremities. The second peculiarity is represented by the tunnel, in other words the ‘convexity’ which is formed during the flight, when the sail is sustained by the wings and in the central part by the keel. The first deltaplanes, equipped with very ‘loose’ sails, made use of the wide tunnel to guarantee the stability of the flight. The modern aircrafts are stiffened by elastics and strengthened by sticks and show a very reduced - or even non existing - tunnel.
HISTORY OF THE DELTAPLANE
The first man who soared into the air with the forerunner of the deltaplane was Otto Lilienthal in the second half of the 18th century. During more than 2000 launches from the hills or from house roofs, he was able to bring to perfection his hang-gliders. But it was not until 1951 when Francis Melvin Rogallo, a Californian aeronautic engineer, patented a ‘flying wing’ that was named after him; this wing was then attentively valuated by NASA, as it united the characteristics of lightness of a parachute and manoeuvrability, which are typical features of other aeroplanes. This wing, however, never soared into the air outside governmental influences. In the sixties, the Australian water skiing instructor Moyes built the first samples of the Rogallo wing that he dragged on the water surface by a speedboat and succeeded in lifting the skier who was hooked to it into the air.
The first ‘purchasable’ deltaplanes appeared in the 1970’s, designed by Moyes and Bennet, but the accidents, which often turned out to be fatal, demonstrated some structural deficiencies of extreme importance; the most important one was due to the fact that the deltaplane is directed by the shift in weight of the pilot, and a deltaplane in perpendicular fall can no longer be controlled. Then a decade of structural evolution followed, together with a relative ‘explosion’ of the phenomenon. Then, around the middle of the 80’s, the deltaplane (or hang-glider) appeared, which offered the possibility to everybody to fly in the most simple way and flying with the deltaplane has become a mainly competitive activity (the aerodynamic performances are even higher compared to the paraglider), whereas the number of ‘amateur’ deltaplane pilots has definitely become smaller.
DELTAPLANE REGULATIONS
The complete list of regulations defining in Italy the ‘Volo da Diporto o Sportivo’ (Recreational or Sports Flight) can be found on the web site of the ‘Federazione Italiana di Volo Libero’ (see external links below). It is enough to underline that the deltaplane is not considered an aircraft (LAW No. 106 dated 25th march 1985), but a device for the Recreational or Sports Flight, as long as it falls into the limits – which are classified in a large range as defined by the Decree dates 19th Nov. 1991, precisely: a single-seater structure, without engine, with a weight not exceeding 80 km; and a two-seater structure, without engine, with a weight not exceeding 100 kg (the above stated weight indications do not include possible safety belts and straps, parachutes, board instruments).
To be able to pilot a deltaplane, you need to present a qualifying certification, acknowledged by the ‘Aereo Club d’Italia’ and issued by one of more than 100 officially recognised schools. The procedures are definitely much easier and shorter compared to the ones when you apply for a flight license for aircrafts (a matter of weeks and a cost of euros in the hundreds, compared to at least one year of training and a cost of euros in the thousands). All regulations concerning hang-gliding are very much simplified, with respect to the ones governing the flight of aircrafts.
