transition altitude การใช้

This setting is equivalent to the air pressure at mean sea level ( transition altitude ).
Aircraft are not normally assigned to fly at the "'transition level'" as this would provide inadequate separation from traffic flying on QNH at the transition altitude.
Once above the transition altitude, the altimeter is set to the international standard atmosphere ( ISA ) pressure at MSL which is 1013.25 hPa or 29.92 inHg.
The "'transition altitude "'( TA ) is the altitude above sea level at which aircraft change from the use of local barometer derived altitudes to the use of flight levels.
However, in some countries, such as Norway for example, the transition level is determined by adding a buffer of minimum 1, 000 ft ( depending on QNH ) to the transition altitude.