{TAIL ~ A lighter than air balloon} is used to offset {HEAD ~ wind turbine weight}, and so to keep it afloat when the wind is not strong enough for flying the wind turbine 
{ TAIL ~ A lighter than air balloon } is used to offset { HEAD ~ wind turbine weight } , and so to keep it afloat when the wind is not strong enough for flying the wind turbine
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH