In one embodiment, {TAIL ~ reference data} could be provided by {HEAD ~ the taxi navigation database} 142 
In one embodiment , { TAIL ~ reference data } could be provided by { HEAD ~ the taxi navigation database } 142
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH