• By Insana Anika
• March 11, 2025March 12, 2025
• Aviation

The different pressure settings used in aviation altimetry: QFE, QNH, and Standard Pressure (1013.25 hPa).

✈ QFE (Field Elevation Pressure Setting)

• When set to QFE, the altimeter reads height above the airfield (AGL – Above Ground Level).
• Example: If an aircraft is 4,000 ft above an airfield with an elevation of 1,000 ft, the altimeter will indicate 4,000 ft height above that airfield.

✈ QNH (Mean Sea Level Pressure Setting)

• When set to QNH, the altimeter reads altitude above Mean Sea Level (MSL).
• Example: If the aircraft is flying at 5,000 ft MSL, the altimeter will indicate exactly that.

✈ Standard Pressure (1013.25 hPa)

• Used above the transition altitude, the altimeter setting is adjusted to the standard 1013.25 hPa.
• The altitude is expressed in Flight Levels (FL) rather than feet.
• Example: FL 55 (Flight Level 55) means approximately 5,500 ft above the standard pressure level.

Understanding these settings is crucial for safe aviation operations, ensuring proper separation and altitude awareness.