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  2. Pressure altitude - Wikipedia

    en.wikipedia.org/wiki/Pressure_altitude

    It indicates altitude obtained when an altimeter is set to an agreed baseline pressure under certain circumstances in which the aircraft’s altimeter would be unable to give a useful altitude readout. Examples would be landing at a high altitude or near sea level under conditions of exceptionally high air pressure.

  3. International Standard Atmosphere - Wikipedia

    en.wikipedia.org/wiki/International_Standard...

    Density and viscosity are recalculated at the resultant temperature and pressure using the ideal gas equation of state. Hot day, Cold day, Tropical, and Polar temperature profiles with altitude have been defined for use as performance references, such as United States Department of Defense MIL-STD-210C, and its successor MIL-HDBK-310. [6]

  4. Barometric formula - Wikipedia

    en.wikipedia.org/wiki/Barometric_formula

    Pressure as a function of the height above the sea level. There are two equations for computing pressure as a function of height. The first equation is applicable to the atmospheric layers in which the temperature is assumed to vary with altitude at a non null lapse rate of : = [,, ()] ′, The second equation is applicable to the atmospheric layers in which the temperature is assumed not to ...

  5. Atmospheric temperature - Wikipedia

    en.wikipedia.org/wiki/Atmospheric_temperature

    Comparison of the 1962 US Standard Atmosphere graph of geometric altitude against air density, pressure, the speed of sound and temperature with approximate altitudes of various objects. [1] Atmospheric temperature is a measure of temperature at different levels of the Earth's atmosphere.

  6. Atmospheric pressure - Wikipedia

    en.wikipedia.org/wiki/Atmospheric_pressure

    One can calculate the atmospheric pressure at a given altitude. [9] Temperature and humidity also affect the atmospheric pressure. Pressure is proportional to temperature and inversely related to humidity, and both of these are necessary to compute an accurate figure. The graph on the right above was developed for a temperature of 15 °C and a ...

  7. Density altitude - Wikipedia

    en.wikipedia.org/wiki/Density_altitude

    The density altitude is the altitude relative to standard atmospheric conditions at which the air density would be equal to the indicated air density at the place of observation. In other words, the density altitude is the air density given as a height above mean sea level .

  8. Altitude - Wikipedia

    en.wikipedia.org/wiki/Altitude

    Pressure altitude is the elevation above a standard datum air-pressure plane (typically, 1013.25 millibars or 29.92" Hg). Pressure altitude is used to indicate "flight level" which is the standard for altitude reporting in the U.S. in Class A airspace (above roughly 18,000 feet).

  9. Lapse rate - Wikipedia

    en.wikipedia.org/wiki/Lapse_rate

    It varies with the temperature and pressure of the parcel and is often in the range 3.6 to 9.2 °C/km (2 to 5 °F/1000 ft), as obtained from the International Civil Aviation Organization (ICAO). The environmental lapse rate is the decrease in temperature of air with altitude for a specific time and place (see below). It can be highly variable ...