B3-6 BALLOON INFLATION AND ASSEMBLY OF TRAIN 
a. Inflate the balloon to a nozzle lift of 1500 grams. 
b. Increase the inflation weight by 300 grams. 
c. Using a watch with a second hand, determine the time, in 
minutes and seconds, required to inflate the balloonthe extra 
300 grams referred to in (b). 
d. Mark the position ofthe exhaust valve of the helium regulator 
or manifold system when it is in position (c). 
e. Using the rate of flow determined in(c), compute the time re- 
quired to inflate the balloon to the required nozzle lift. Once 
the rate of flow has been determined, the value may be used 
until the regulator, tubing or nozzle is replaced, at which 
time a new determination should be made. The rate of flow 
method should be checked with inflation weights, using a bal- 
loon which does not touch the ceiling. The required inflation 
weights should be installed even though the flow rate is used. 
When the constant-rate inflation method is used, the cylinder should be 
replaced when the gas pressure drops to 100 psi, since the rate of flow 
then no longer remains constant. The partial cylinder of gas should be 
used at the beginning of the next inflation. If the ceiling of the inflation 
shelter is too low to determine the flow rate in accordance with the above 
instructions, the flow rate should be determinedina hangar or outdoors 
during a period with calm winds. The constant-rate inflation method must 
not be used unless the balloon is likely to touch the ceiling before the de- 
sired nozzle lift is reached. 
4. Tying the Neck. Tie the neck of the balloon with a 6-foot length of 
double cord as soon as inflation has been completed. Make one turn of 
the doubled cord around the neck of the balloon near the center (close to 
the top of the inflation nozzle). Adjust the doubled cord so that a free end 
of about 5 feet and another of about 1 foot in length result. Pull the cord 
as tightly as possible and tie with a square knot. Make another turn 
around the neck and tie again. Remove from the nozzle, fold the neck up- 
ward and again tie the neck just above the first knot. Be sure that all 
cord is below the area where the neck starts to flare out to join the en- 
velope of the balloon. 
3. The Inflated Balloon. The balloon should be left in the inflation 
shelter until preparations for the release have been completed. If the re- 
lease is not expected to occur within 15 minutes after the inflation is 
completed, the balloon should not be held down by weights attached to the 
1-1-69 FMH#3 
