critical altitude


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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 altitude

i. 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.
References in periodicals archive ?
The height at which sprites spark to life also roughly agrees with what theorists like Pasko estimate to be the critical altitude for breakdown.
Besides calculating the critical altitude at which a breakdown-driven sprite should emerge, the theorists have predicted the shape of the radio pulse that the breakdown should generate and the color it should appear.
This includes critical altitude information for compliance to new mandatory reduced altitude separation standards (RVSM, Reduced Vertical Separation Minimum), airspeed and altitude as well as engine and fuel data measurements.