B3-4 BALLOON INFLATION AND ASSEMBLY OF TRAIN 
b. The performance obtained in the preceding flights may be con- 
sidered in selecting a free-lift value to be used. 
c. When precipitation, icing, or terrain turbulence is occurring 
or expected, an effort will be made to provide sufficient free 
lift to insure that the balloon will not descend or float. An in- 
creased free lift of 100 grams is normally sufficient to com- 
pensate for an increase in the weight of the train resulting 
from light precipitation. Under light or moderate icing condi- 
tions, moderate to heavy precipitation, or terrainturbulence, 
an increase in the free lift of from 200 to 300 grams will usu- 
ally be sufficient. Under severe icing conditions, anincrease of 
up to 500 grams may be required. 
d. Whenever an observation is to be made during periods of 
strong winds aloft that will cause loss of wind data owing to 
limiting angles at nontransponder stations, or the loss of 
meteorological data at transponder stations the balloon should 
be inflated to obtain the highest possible ascensional rate. 
However, increasing the lift beyond 300 grams in excess of 
the values given will often decrease the ascension rate for the 
sounding from the surface to the level of maximum wind. 
e. Attach the weights required to give the desired nozzle lift to 
the inflation nozzle, making allowance for part of the hose that 
will be supported by the balloon as well as the nozzle itself, 
hose clamps, cut-off valves, etc. (usually 200 to 400 grams). 
3. Inflation of Balloons. After the weights have been placed on the 
inflation nozzle, inflation should be started as soonas the balloon is re- 
moved from the conditioner except when drying is required. When the 
electric balloon conditioner is used, any air should be forced out of the 
balloon before attaching the neck to the inflation nozzle. If the balloon is 
not conditioned, the inflation nozzle should be inserted into the neck be- 
fore removing it from the plastic bag. Ineither case, the balloon should 
be handled as little as possible. 
3.1 Inflating With Hydrogen or Natural Gas. If the balloon is to be 
filled with hydrogen or natural gas, posted safety instructions and safety 
instructions issued by the separate services will be followed and protec- 
tive gear worn at all times during the inflation and tieing off of the bal- 
loon. If a partially full or completely filled balloon is discovered to be 
leaking, open one of the inflation doors, take the balloon outdoors and let 
the hydrogen or natural gas escape from the balloon. This may be done 
by rolling the balloon from the top to the neck. Reject the balloon and 
begin inflating a second balloon. 
I> (6s) FMH#3 
