Alternately, the aircraft fuel system control circuit may be upgradable to {TAIL ~ an optional aircraft fuel system control circuit} including {HEAD ~ a partially or fully populated jettison control circuit} 
Alternately , the aircraft fuel system control circuit may be upgradable to { TAIL ~ an optional aircraft fuel system control circuit } including { HEAD ~ a partially or fully populated jettison control circuit }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD