text: Insertion and Extraction Methods
  Obstacles
  5-85. For planning purposes, use an obstacle clearance ratio of 10 to 1 on the approach and departure
  ends of the PZ and LZ. That is, a helicopter approaching or departing directly above a 10-foot tall tree
  needs 100 feet of horizontal clearance. Mark obstacles within the PZ and LZ only if the enemy cannot see
  the markings. At night, mark them with red lights, but turn them on only when the PZ or LZ is in use. In
  the daytime, use red panels instead of lights.
  Approach and Departure
  5-86. Analyze the terrain surrounding a possible PZ or LZ for air traffic patterns. In a tactical situation,
  avoid repeatedly approaching the PZ or LZ over the same ground. Choose approaches that are free of
  obstacles. Pilots should land into the wind, but away from the sun. Ideally, they approach and depart along
  the axis of the LZ, over the lowest obstacle, and into the wind.
  Load Size
  5-87. When a helicopter is loaded to near maximum lift capacity, it needs more distance to lift off and
  land. It cannot ascend or descend vertically. The nearer the load to maximum, the larger the PZ and LZ
  must be to accommodate a flight.
  Operations
  5-88. Before the aircraft arrives, the PZ control party secures the PZ. Both the PZ control party and the
  Soldiers and equipment are positioned in the LRS team PZ or ORP. When occupying the team PZ or ORP,
  the team leader should (Figure 5-13) —
  • Maintain all-round security of the PZ or ORP.
  • Maintain communications (ground-to-air).
  • Brief the marking team for the exact aircraft landing point, and check their equipment.
  • Establish priority of loading for each Soldier.
  • If time permits a detailed plan, use a coordination checklist.