Airport Installations

AIR BAGS TRIAL Trials have been carried out by the RAF to evaluate the aircraft recovery system of Hovertrailers International Ltd. In a simulated accident, a Hastings, weighing 35 ton including ballast, was stranded on its belly on rough ground at the perimeter of the airfield. The aircraft was raised on air bags and, when the hover platforms were in position, was manoeuvred forwards, backwards, sideways, and turned on its axis on the rough ground to prove the versatility of the hover system. Afterwards, the aircraft was hovered across the airfield — a distance of about ¾ mile — at speeds of up to 10mph using a Sentinel vehicle as a towing unit. The manoeuvres were then repeated on level grassland and taxiways. For this aircraft a complex of three hover units was used. Twelve units, connected in threes to form four platforms, can recover a Boeing 747. The whole system is based on a module 10ft by 7ft 4in. and can be transported in a Boeing 707 freight aircraft. It comprises a combination of airbags and hoverplatforms. The airbags act as an interface medium between hoverplatform and aircraft. The hoverplatforms act as a suspension and transport system, and must be placed so that the loads exerted by the aircraft are in balance during movement. Each combination of airbag and platform takes a predetermined share of the total load. Therefore, the number of bags and platforms required is dependent on the weight of the aircraft, and their disposition depends on the aircraft CG.