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