What does QFE indicate regarding an altimeter's reading?

The correct interpretation of QFE is that it indicates the vertical distance above a specific datum, typically the airfield elevation in aviation settings. When an altimeter is set to QFE, it measures the altitude above the reference point (which is often the runway level), allowing pilots to determine how high they are above that specific level.

In practical terms, when the altimeter is set to QFE, it reads zero at the reference point used in the setting—meaning if a pilot is at the airfield, it shows zero altitude. As the aircraft ascends, the altimeter will provide the height above that particular surface level, which is particularly useful for operations in the vicinity of the airfield or during landing approaches.

The other options do not accurately represent what QFE signifies. Altitude above mean sea level pertains more closely to QNH settings, while standard atmospheric pressure level refers to a reference value used for atmospheric pressure but doesn’t specify altitude relative to a specific location. Pressure condition at cruising altitude is not defined by QFE, as QFE is specifically tied to the ground level and not to the atmospheric conditions at higher altitudes.