Flight Manual for Gas Balloons of Type NL-STU
Issue 2.0
May 02, 2016
Page 2-6
2.9 Appendix
Before take-off and during ascent, the appendix must be completely opened.
WARNING:
Take-off and ascent with the appendix closed are not permitted, as the envelope
is otherwise subjected to an inadmissibly high overpressure.
2.10 Maximum rate of climb and descent
The rate of climb must not exceed 10 m/s.
WARNING:
In the case of an inflation level of less than 50 percent and a rate of climb of more
than 10 m/s, there is a risk of the parachute opening itself.
The maximum permissible rate of descent depends on the quantity of ballast available for
reestablishing equilibrium of the balloon.
NOTE:
The braking ballast required for reestablishing equilibrium of a 1000 m³ balloon is cal-
culated using the following rule of thumb: Rate of descent in m/s squared times the
drag coefficient of the balloon size.
Example: Balloon size 1000 m³, rate of descent 3 m/s, drag coefficient 4:
=> 3 x 3 x 4 = 36 kg of braking ballast.
Drag coefficient for all balloon sizes:
380 m³
510 m³
640 m³
840 m³
1000 m³
2,0
2,4
2,8
3,4
4,0
2.11 Operating the parachute as a maneuvering valve
When the parachute is being used in its function as a maneuvering valve, it must not be pulled
beyond the point at which the line starts to vibrate.
CAUTION:
The parachute must be opened slowly so that the vibration in the line can be
clearly felt.
WARNING:
If the parachute line is pulled beyond the vibration point, the parachute loses its
function as a maneuvering valve and only functions from this point onwards as a
quick deflation device!
