| 释义 |
critical altitude
critical altitudeThe altitude beyond which an aircraft or airbreathing guided missile ceases to perform satisfactorily. See also altitude.critical altitude
critical altitude[′krid·ə·kəl ′al·tə‚tüd] (aerospace engineering) The maximum altitude at which a supercharger can maintain a pressure in the intake manifold of an engine equal to that existing during normal operation at rated power and speed at sea level without the supercharger. (ordnance) The maximum altitude at which the propulsion system of a missile performs satisfactorily. critical altitudei. A specified altitude or height in the precision approach at which a missed approach must be initiated if the required visual reference to continue the approach has not been established. Decision altitude is with reference to mean sea level, while decision height is with reference to the threshold elevation. The visual reference means that section of the visual aids or of the approach area that should have been in view for a sufficient time for the pilot to have made an assessment of the aircraft's position and change of position in relation to the desired flight path.
ii. The altitude beyond which an aircraft reciprocating engine cannot maintain normal-rated power, or in some contexts, beyond which it cannot maintain military-rated power. |