Plain English Meaning

QNE is the fixed pressure setting (29.92) every pilot dials into the altimeter once they climb high enough. Above that altitude, everyone uses the same setting so all aircraft are measuring height from the same starting point, even if the real outside pressure is different.

Full Definition

QNE is the standard barometric pressure setting of 29.92 inches of mercury (1013.2 hPa) entered into the altimeter when operating at or above the transition altitude or in airspace where flight levels are used. With QNE set, every aircraft references the same pressure datum, so altimeter readings are expressed as flight levels rather than true height above sea level. In the United States, QNE is required at and above 18,000 feet .