F. Flight Termination Gear
The rate of descent when controlled balloons are falling after exhausting all ballast is sometimes as slow as 50 feet per minute. This means that several hours might be required to fall through the lanes of aircraft traffic, increasing considerably the hazard to aircraft (admittedly very small). To minimize this possibility, units have been added to the flight train to cause a rapid descent after the balloon system has descended to some critical value, say 20,000 feet. One such destruction system, using a flight-termination switch, is shown in Figure 21. It consists of a pressure-activated switch, triggered on descent only, an explosive charge used to sever
[figure]
Figure 21. Flight termination equipment.
the main load line, a rip line attached to the balloon near the equator and a snub line which takes up the strain after the load has fallen a few feet.
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