text: Helicopter Landing Zones
  INTERCEPT HEADINGS
  4-49. The heading from the RP (or from the CCP if the pathfinders do not use an RP) to the landing site
  coincides as closely as possible with the landing direction to keep the helicopter from having to turn
  sharply. The larger the formation, the more important this becomes. If a pilot cannot approach the landing
  site straight on, pathfinders will set up an intercept heading (Figure 4-15). They choose an intercept point
  far enough from touchdown to allow helicopters in formation a final approach of at least 1 to 2 miles.
  Flight leaders might need visual steering commands, time and distance information, terrain features, and
  electronic or visual navigation aids to help them determine the intercept point and the landing direction at
  the landing site.
  Figure 4-15. Intercept heading technique.
  SECTION IV. LANDING ZONE OPERATIONS
  Helicopters approach the LZ along a designated flight route. They normally travel in serials containing four or
  five helicopters, but they sometimes travel as platoon-sized lifts. One serial might contain a flight for each
  helicopter site. Flights of medium or heavy transport helicopters (CH-47) carrying artillery or other bulk cargo
  often arrive at LZs one or two helicopters at a time (Figure 4-16). Later flights follow at the smallest time
  intervals. These intervals depend on the number of helicopters in each flight, the configuration and conditions
  of the landing site, and the nature of the cargo to be loaded or unloaded. During planning, the aviation unit
  commander determines the time between successive flights. Once an operation starts, pathfinders at the site
  recommend any changes needed to ensure helicopter safety or expedite operations. Night operations often
  require more time and distance between formations.
  COMMUNICATIONS CHECKPOINT
  4-50. As each helicopter serial reaches the CCP on the flight route, the flight leader contacts the
  appropriate helicopter landing site control center.
  4-51. The CC then gives the flight leader the heading from the CCP to the landing site, the landing
  direction, and other relevant and important information, as follows:
  y Enemy situation.
  y Friendly fires.