TRANSITION ALTITUDE Meaning and
Definition
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Transition altitude is a term used in aviation to define a specific altitude at which aircraft shift their altimeter settings from a locally determined reference value to a standardized international reference value. It is the altitude at which aircraft climb through during takeoff from an airport or descend through during landing. This transition is typically made to ensure uniformity and consistency in altitude measurements for aircraft operating in different regions and countries.
The transition altitude is determined by aviation authorities and is usually set at a level above the highest ground or obstacle in the vicinity of the airport, ensuring a safe altitude for aircraft operations. Pilots initiate the transition by changing their altimeter setting from the local QNH (altimeter pressure setting adjusted for atmospheric conditions) to the standard QNE (standard atmospheric pressure setting of 1013.25 hectopascals or 29.92 inches of mercury).
Transition altitudes vary across different locations, depending on factors such as terrain, air traffic control requirements, and local regulations. The transition altitude is important for pilots as it marks the point where vertical altitude separation is based on a standardized pressure setting, facilitating safe and accurate altitude reporting and aircraft separation. Flying above this altitude necessitates using flight levels, while flying below it requires altitude measurements.
In summary, the transition altitude is the specific altitude where aircraft switch their altimeter settings from local reference to a standardized international reference, ensuring uniformity in altitude measurements and facilitating safe aircraft operations.
Etymology of TRANSITION ALTITUDE
The term "transition altitude" comes from the etymology of two words: "transition" and "altitude".
The word "transition" originated from the Latin word "transitio", which means "to go across" or "to change". It entered the English language around the 14th century and initially referred to the process of changing or passing from one state or condition to another.
The word "altitude" has its roots in the Latin word "altitudo", which means "height" or "elevation". It is derived from the Latin word "altus", meaning "high". "Altitude" entered the English language in the mid-16th century and is used to describe the vertical distance or height above a fixed reference point, such as sea level.
