Tetrahedron

{
  "id": "MLC-T-AVN-000993",
  "term": "Tetrahedron",
  "field": "Aviation and air traffic control",
  "definition": "A device normally located on uncontrolled airports and used as a landing direction indicator. The small end of a tetrahedron points in the direction of landing. At controlled airports, the tetrahedron, if installed, should be disregarded because tower instructions supersede the indicator.",
  "see_also": [
    "Segmented circle"
  ],
  "references": [
    "AIM",
    "FAA Pilot/Controller Glossary"
  ],
  "url": "https://mlchart.com/terminology/aviation/tetrahedron/"
}