Flight Manual for Gas Balloons of Type NL-STU
Issue 2.0
May 10, 2019
Page 4-14
4.10.1 Checking the ropes
During flight, permanent care must be taken to ensure that the lines that are fastened to the
basket or load ring, such as the parachute line, appendix pull-close line and emergency opening
line, have sufficient slack, that the appendix anchor lines are not under tension, and that every-
thing is easily accessible at all times.
4.10.2 Venting the lifting gas
If the parachute is used as a maneuvering valve (flight valve), the parachute line may only be
pulled down
slowly
until the parachute becomes
leaky
. The escape of gas is indicated to the
pilot by a clearly audible hissing sound. Lifting gas should be vented by briefly and repeatedly
opening and closing the parachute until the balloon responds.
WARNING:
The way in which the parachute functions as a maneuvering valve differs signifi-
cantly from the flap valve of a traditional gas balloon. For this reason, adequate
instruction in the proper use of the parachute is required.
Vibration in the line indicates the maximum permissible degree of opening for venting gas dur-
ing maneuvering.
WARNING:
Pulling hard on the parachute line for a long time results in the need for a large
quantity of braking ballast. The parachute must always be
pulled slowly
so that
the vibration in the line can build up.
This vibration in the line is the only safe indication to the pilot of the transition
between the maneuvering effect of the parachute and the quick deflation effect.
In the case of quick deflation, the balloon loses approx. 300 to 500 N of lifting ca-
pacity power per second, which corresponds to a weight of approx. 2 to 3 ballast
bags.
4.10.3 Observing the variometer
Observe the variometer to evaluate the behavior of the balloon during ascent and descent.
4.10.4 Dropping ballast
In order to cause the balloon to ascend, fine-grained ballast must be dropped from the sand
container or directly from the sand bag.
NOTE:
In addition to sand, several kilograms of water ballast can also be carried. This water
is poured out if it is necessary to drop ballast over sensitive areas. The water is stored
in canisters with a large opening for pouring and is secured and stowed in a similar way
to sand bags.
The water ballast has to be protected against freezing.
