1. This group contains the spherical envelope, two ballonets, two batten assemblies and t h phere rotation system. The envelope wi 11 be constructed from a polyurethane coated eight-ply polyester fabric weighing approximately 12 ounces per square yard, resulting i n a weight of 1850 kg. This estimate includes the weight of four twenty-inch diameter gas valves. The b a l l o n e t s are hemispherical envelopes located at the axles with a total volume of 14 percent of the vehicle gross volume. This results i n a pressure altitude of 1500111 for the aircraft. The ballonets w i l l be constructed from a three-ply polyester fabric weighing approximately 4 ozlyd 2. The ballonets, pressure relief valves and blowers w i l l weigh approximately 180 kg. The batten assemblies are similar i n design t o the nose battens used on conventional airships. I n particular, the batten assemblies are 25 percent of the diameter of the hull and are composed of tapered graphitelglass epoxy tubes. The total weight of the batten assemblies, which include the end axles, i s 450 kg. The sphere i s required to rotate at 7 rpm i n order t o achieve a spin rate of one at a cruise speed of 90 kph This would require a ten horsepower hydraulic winch gearbox, pump, piping and fluid weighing approximately 200 kg i n total. Ai rfrarne Structures Group
2. The various components which constitute this group are contained i n Table 2. With the exception o f cargo-handling equipment they are similar i n mass d i s t r i b u t i o n t o those systems found on conventional transport aircraft. Thus their mas estimates were based on data from Torenbeek. 8 This LTA 20-1 configuration i s designed to carry slung payloads. Thus a l l it requires i s a cable, a quick release cargo hook, and a hard point located on the bottom of the ringwing. This equipment should weigh approximately 200 kg.