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