if the threat risk value of any of the grid cells intersecting the flight path exceeds the allowable threat risk per grid cell, identifying {HEAD ~ an intermediate point} from which to deviate the flight path based upon {TAIL ~ an analysis} of the cumulative threat risk values of the grid cells 
based upon
if the threat risk value of any of the grid cells intersecting the flight path exceeds the allowable threat risk per grid cell , identifying { HEAD ~ an intermediate point } from which to deviate the flight path based upon { TAIL ~ an analysis } of the cumulative threat risk values of the grid cells
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH