text: Drop Zones
  6-110. At night, replace the panels with lights. Make the code letter at least four lights high by three
  lights wide, with 5 meters between each light. To limit ground observation, you may place the code letter,
  flank, and far light in holes as follows:
  y Place the code letter and far light in directional holes.
  y Place the flank light in a bidirectional hole (toward RP and direction of aircraft approach).
  y If the RP falls off the DZ, hide the markings, or if the DZSTL cannot see the aircraft, he can
  change the parachute drop to a jumpmaster-directed release operation using the wind streamer
  vector count (Figure 6-13).
  Figure 6-13. Wind streamer vector count.
  y If the RP falls off the DZ and the DZSTL cannot, due to the tactical situation, position himself
  at the RP, then he can conduct an offset release (late, left, or right). To do this, he determines
  how many seconds the aircraft must fly past him before initiating the release. He gives the
  aircraft steering corrections to fly over the RP, just as in a standard VIRS. However, when the
  aircraft has flown a set distance past the control center, the Pathfinder commands the pilot to
  "turn drop heading" or “execute.” In Figure 6-14, the drop speed is 70 KIAS. The RP falls
  about 80 meters off the DZ, and the old and new control centers are 118 meters apart.
  Multiplying 70 KIAS by .51 equals 36 meters per second of flight. The 3 second offset places
  the RP about 118 meters from the control center or code letter. The DZSTL, code letter, and
  control center are positioned on the DZ at a distance from the RP that is rounded off to the
  nearest second.
  Note: These same procedures may be used when the tactical situation prevents the pathfinder
  from positioning himself on the release point, but he must remain in a concealed location and
  call the VIRS drop offset from his position.