безпілотний вільний аеростат (некерована повітряна куля)
free balloon
unmanned balloon
accident-free flying / mishap-free flying
mishap-free flying / accident-free flying
study group on unmanned free balloons
barrage balloon
balloon bed
balloon observation
balloon tire
balloon wing
balloon-launched aeroballistic
ballonet balloon
balloon
balloon envelope
observation balloon
balloon probe
balloon sounding
captive balloon
constant-level balloon
dirigible balloon
pilot balloon
radiosonde balloon
target balloon
captive balloon-borne communication
radar decoy balloon
air balloon
balloon-borne radiosonde
radar target balloon
radiosonde balloon (rabal / RABAL)
radiosonde balloon release
radiosonde balloon wind data
balloon barrage