STUDY OF FLEXIBLE JET EXTENSIONS FOR AIR CUSHION VEHICLES, PHASE III.
BELL AEROSYSTEMS CO BUFFALO N Y
The performance of commercially available materials in flexible trunks for air cushion vehicles was evaluated. An advanced design concept was developed for a flexible trunk to provide loadings in testing similar to those experienced in operation with inflated bag-type trunks. A specification setting the limiting values for critical properties of flexible trunk material was written. Four new materials supplied by vendors in response to the specification were laboratory tested for tear strength, tensile strength, elongation, abrasion resistance, and other related properties. Performance of the new materials, which consisted of nylon coated with hypalon, neoprene, poly vinyl chloride, and polyurethane, respectively, were compared with the performance of nylon coated with U. S. Rubber 105-4-108, which had been tested previously in full-scale operation. Model flexible trunks were fabricated from selected materials and tested on the Bell rotating arm facility to evaluate performance, wear characteristics, and comparable life expectancy.