the aircraft display unit is comprised of {HEAD ~ a head up display unit} configured to display {TAIL ~ the image} represented in the synthetic image data 
the aircraft display unit is comprised of { HEAD ~ a head up display unit } configured to display { TAIL ~ the image } represented in the synthetic image data
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH