Answer: updraft

AnswerCrossword Clue
UPDRAFTGlider's booster
UPDRAFTCondor's booster
UPDRAFTWhat keeps a glider aloft.
UPDRAFTAir current.
UPDRAFTHang glider's aid
UPDRAFTKite aid
UPDRAFTAir current heading skyward
UPDRAFTIt gives hang gliders a lift
updraftan upward movement of gas (as air)
updraftan upward movement of air