Altimeter

     Altimeter is the instrument which shows the aircraft’s altitude from sea level. The measuring method is based on proportional reduction of the air pressure in relation to altitude. Essentially, it’s a barometer which measures the pressure of the atmosphere in a mathematical calculation, based on the International Standard Atmosphere (ISA). The altitude is measured in feet. In every cycle of the instrument’s indicator, altitude changes by 1,000 feet.

     Most modern altimeters have a second indicator, measuring tens of thousands of feet. As the barometric pressure is different every time in a region, depending on the weather conditions, this instrument has a regulator in which the pilot enters the local barometric pressure adjusted to sea level (QNH), to have always correct altitude indications. This pressure is indicated on the instrument in a special area. In America , this pressure is measured in inches of mercury (inHg) and in Europe in hectopascals (hPa) or mBar.

For FlightSimmer.GR
 Giannis Evagelinos   

 see the video for more information