text: THIS CHAPTER IMPLEMENTS QSTAG 585 AND STANAGs 3281 AND 3619.
  Chapter 4
  Helicopter Landing Zones
  Helicopter landing zones contain one or more helicopter landing sites. Each landing
  site has a control center and, in most cases, a manned or unmanned release point
  (STANAG 3619). Each landing site might have one or more specific landing points
  for individual aircraft to touch down.
  SECTION I. SELECTION OF LANDING SITES
  The ground unit commander coordinates with the supporting aviation unit to select helicopter landing zones
  that can support the ground tactical plan.
  CONSIDERATIONS
  4-1. Tactical considerations are those that pertain to the actual mission of the supported ground unit.
  These considerations are the responsibility of the ground unit commander and staff. The pathfinder must
  understand the ground tactical plan to best support the ground unit and facilitate mission accomplishment.
  TACTICAL CONSIDERATIONS
  4-2. These include—
  y An estimate of the situation based on METT-TC.
  y The location of the objective in relation to the tentative HLZ.
  y The size and type of unit being supported.
  TECHNICAL CONSIDERATIONS
  4-3. These pertain to the technical aspect of the operation of a day or night HLZ. These are the
  responsibility of the pathfinder. The minimum landing space requirements and minimum distance between
  helicopters on the ground depend on many factors. If the aviation unit SOP fails to spell out these
  requirements, the aviation unit commander works with the pathfinder leader. The final decision about
  minimum landing requirements rests with the aviation unit commander. In selecting helicopter-landing
  sites from maps, aerial photographs, and actual ground or aerial reconnaissance, the pathfinder considers
  the following factors (Figure 4-1, page 4-2):
  NUMBER AND TYPE(S) OF HELICOPTERS
  4-4. To land a large number of helicopters at the same time, the commander can provide another
  landing site(s) nearby or he can have the helicopters land at the same site, but in successive lifts. A larger
  site might also be required for cargo aircraft with external loads as compared to several utility aircraft. The
  required size of the site is determined by the size and number of aircraft that will be required to land at a
  given time. A landing point, or touchdown point (TDP), is the specific point on the ground for a specific
  aircraft. The size of the landing point is determined by the aviation unit commander and is based on—
  y Pilot or unit proficiency.
  y Size and type of aircraft.
  y Atmospheric conditions.