This altitude-control system operated well enough to produce a height-time curve (Figure 4) with one descent checked by ballast dropping. Too much weight was lost in this action, and the train rose until some of the balloons were burst. Subsequent descent was not checked.
[figure]
Figure 4
From this flight it appears that the inherent instability of freely extensible balloons is so great that no simple control will cause them to remain at one pressure level.
Tracking for the entire flight period was accomplished with a C-54 aircraft. Two theodolite stations were operated, one at the launching site and one at Wafford Lookout, a fire tower about 20 miles northeast of the release point.
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