The chart showing the altitude and speed
April 26 2010
The chart showing the altitude and speed of the balloon using data recorded during the flight illustrates the problems encountered by the expedition.
N.B. in particular:
- the long flight at low altitude (some sixty consecutive hours at an altitude of less than 300 m, sometimes less than 100 m), requiring constant vigilance, which made it impossible to sleep for more than a few minutes.
- strong, turbulent winds: 21 consecutive hours of winds blowing at more than 50 km/hr (force 7), with 3 hours at around 90 km/hr (45 knots, force 9-0) when the balloon was at low altitude. The winds were accompanied by turbulence that caused the balloon to rise very high and then fall just as violently (the variometre blocked at 5-6 metres per second).
- rapid, major altitude variations, with about ten hours of flight time at an altitude of more than 5,000 m, at a pressure equal to half the atmospheric pressure on the ground and the need to use artificial oxygen.