Category
page 1Altitudes in aviation
height above mean sea level
elevation of a location in reference to a historic mean sea level taken as a vertical datum
flight level
aircraft's altitude at standard air pressure, expressed in hundreds of feet
Armstrong limit
altitude above which water boils at human body temperature, making it absolutely impossible for humans to survive unpressurized; approx. 18–19 km above sea level
ceiling
maximum density altitude an aircraft is specified to reach
reduced vertical separation minima
height reduction of aircraft in flight
density altitude
altitude relative to the standard atmosphere conditions
height above ground level
height measured with respect to the underlying ground surface
Lowest safe altitude
Minimum en route altitude
the recommended minimum altitude for a segment of an airway