{HEAD ~ A drop vehicle} is positioned in {TAIL ~ the tube} or tower above the projectile so as to impact on the projectile when released and subjected to gravitational force 
{ HEAD ~ A drop vehicle } is positioned in { TAIL ~ the tube } or tower above the projectile so as to impact on the projectile when released and subjected to gravitational force
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH