Transition altitude (TA)

Transition altitude is the altitude at or below which vertical position is expressed as altitude using QNH. Above the transition altitude during a climb, the altimeter is set to standard pressure, 1013.25 hPa, and position is expressed as a flight level.

German term

Übergangshöhe (Transition Altitude)

Abbr.

TA

The transition level is the lowest available flight level above the transition altitude; the space between them is the transition layer. In descent, change from standard pressure to QNH at the transition level. Transition altitude is published locally and is not the same in every country or at every aerodrome; the transition level depends on the applicable pressure conditions.

For general information only. Always use official sources, your aircraft's flight manual and current national rules for flight decisions.