18.
When the system again descends to 25,000, the pen arm comes into contact with the commutator contact and an electrical circuit is closed through a squib in the load line. The load line is cut and the load on the system falls six to eight feet before being caught by a supplementary load line. During this fall a rip line pulls a hole one foot long in the side of the balloon and the system descends using the partially inflated balloon to hold the rate of descent to approximately 1200 ft/minute. This system has been used successfully in over 100 flights.
A drawing of the rip assembly is shown as Fig. 13. The cannon and squib to cut the load line are shown as Fig. 14.
[figure]
Fig. 13
Balloon Rip Assembly