The subject of glider launching by hot air balloon came up in another NG. I remember hearing that hang glider pilots have launched (dropped) from hot air balloons, but what about heavier aircraft?
What is the maximum weight a typical balloon can lift? Could a glider with a gross weight of as much as 1000 lb be carried aloft? And can a balloon suddenly lose most of its payload without climbing so fast that it gets damaged? What are the structural/dynamic issues involved?
Thanks in advance - - Bob O
The Thunder & Colt flight manual provides launch (drop?) procedures for hang gliders.
An example of balloon lift ratings - a 105,000 Cu. Ft. balloon can lift as much as 2400 pounds. The lift is reduced by factors such as altitude and temperature. The balloon system itself weighs between 600 and 700 pounds fueled. Add 400 pounds for a pilot and a passenger, and it still has about 1300 pounds lift.
One of the manufacturers was flight testing a large envelope using a 2500 pound Toyota as ballast, until his local FSDO called him and demanded he stop, as the system was not rated for glider towing. Maybe he should not have asked them, 'Do you know what the glide ratio of a Toyota is?'
Alan's right. In addition, dropping parachutists is much the same, in that the proper procedure is to gain proper altitude, then start a slight decent before dropping them over the side. The weight lost gives an immedite rebound in the other direction. The most I've ever dropped at once was eight, and it was a 600 per minute decent, then a 1,200 per minute climb in a Colt 160A.