The Roswell Report: Fact vs. Fiction in the New Mexico Desert

Figure 15. Theoretical height-time curve. (4) Rate-of-Descent Switch It may at times be desirable to control a balloon merely by a switch activated at any given rate of descent. This could be accomplished merely by "reversing" the rate-of-ascent switch. This type of control would prove to be quite difficult, however, for a constant level flight. One flight, No. 97, was made using a type of rate-of-descent switch as shown in Figure 16. In Figure 16. Rate-of-descent switch.