Tetrahedron

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.

Source: FAA Pilot/Controller Glossary (definition from the 2023 edition; current: Change 1 of 7 August 2025).

Reference: AIM.

See also

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Glossary last updated 2026-10-28.

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