text: Helicopter Landing Zones
  Multiple Landing Sites
  4-86. Depending on the mission requirements, climatic conditions, and the expected times of the
  landings, the pathfinder leader might decide to use multiple landing sites.
  Night Approaches
  4-87. Aircraft making night approaches to snow sites need a visual reference point on the ground such as
  runway or tactical landing lights. These lights help the pilot judge the angle of descent and rate of closure.
  He plans the approach to land short of the touchdown point. This ensures that he does not overshoot the
  point and have to decelerate rapidly in the snow cloud produced by his own aircraft. Approaching short
  allows the pilot to maintain airspeed after leveling off, and to keep the aircraft in front of the snow cloud
  until touchdown.
  Adjustment of Inverted "Y"
  4-88. If he coordinates with the flight commander before the landing, the pathfinder can adjust his
  inverted "Y" forward 10 meters in front of his designated Number 1 touchdown point. This way, the
  landing site party takes advantage of all usable areas on the site.
  SIGNALMAN
  4-89. The pathfinder leader positions any extra personnel to act as signalmen for aircraft approaching
  other touchdown points. While aircraft approach and land, he makes sure that signalmen remain in safe
  areas. Other signalmen should also control the loading of personnel on the aircraft, as instructed by the
  crew chief or the crew. The technique for landing on snow with a slingload resembles other types of
  approach, but the pilot hovers at a higher altitude because of the load (A, Figure 4-21). He has a hard time
  judging the height of the slingload (the height above the ground) as it nears the snow surface. He relies on
  a signalman to keep him informed. To avoid building up a snow cloud, the pilot puts the load on the
  ground as fast as he can (B, Figure 4-21).
  SLINGLOAD OPERATIONS
  4-90. The CH-47 requires a sling length of at least 50 feet. Other aircraft allow a shorter sling. Normally
  an aircraft hovers during hookup and liftoff with a slingload. Doing this above snow produces a snow
  cloud (B, Figure 4-21). The pilot must expect this and plan for it. In fact, when operating over
  snow-covered terrain, the pilot can use the most common technique—hovering the helicopter over the load
  while the ground crew attaches the sling to the hook—or not.
  4-91. The pilot can land to the left of the load, but close enough for hookup personnel to attach the
  sling to it.
  4-92. When ready for liftoff, the pilot starts a slow, vertical ascent, with enough lateral movement to
  position the aircraft over the load (C, Figure 4-21). He keeps ascending until the load clears the ground,
  and then he checks hover power, starts accelerating, and continues to climb.
  WARNING
  Rotor wash increases the risk of frostbite. Make sure you and
  anyone else on the ground dresses for the conditions and keeps
  or uses a face mask and goggles.