{TAIL ~ Airplanes} have transponders which receive and transmit {HEAD ~ signals} to communicate information regarding the flight of the airplane 
{ TAIL ~ Airplanes } have transponders which receive and transmit { HEAD ~ signals } to communicate information regarding the flight of the airplane
TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH