decision height

An instrument approach or instrument approach procedure (IAP) is a type of air navigation that allows pilots to land an aircraft in reduced visibility (known as instrument meteorological conditions or IMC), or to reach visual conditions permitting a normal landing.Approaches are classified as either precision or nonprecision, depending on the accuracy and capabilities of the navigational aids (navaids) used. Precision approaches utilize both lateral (course) and vertical (glideslope) information. Nonprecision approaches provide lateral course information only.
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With respect to the operation of aircraft, means the height at which a decision must be made, during an Instrument Landing System (ILS) or Precision Approach Radar (PAR) instrument approach, to either continue the approach or to execute a missed approach. (14CFR1)

A height above the highest elevation in the touchdown zone, specified for a glide slope approach, at which a missed-approach procedure must be initiated if the required visual reference has not been established. See also decision altitude. 1/6/78

Hauteur au-dessus du point le plus élevé de la zone de posé, spécifiée pour une approche de précision, à laquelle une procédure d'approche manquée doit être amorcée si le contact visuel nécessaire n'a pas été établi. Voir aussi altitude de décision. 1/6/78

With respect to the operation of aircraft, means the height at which a decision must be made during an ILS, MLS, or PAR instrument approach to either continue the approach or to execute a missed approach.
(See ICAO term DECISION ALTITUDE/DECISION HEIGHT.)