How High is a Plane Flying Over the Anaheim Hills?

Very general questions for pilots who fly into SNA (Orange County, CA) – I’m trying to find out how high the planes flying over my house in Anaheim Hills would be from my vantage point. The Anaheim Hills are about 800 feet high, so if your altimeter says you’re at 2800 feet altitude, are you 2000 feet above me, or are you 2800 feet above me? In other words, are you getting readings of how high you are above any given mountain area, or how high above sea level you are?

Sorry, I’m not a pilot and know nothing about this.

The normal (barometric) altimeter gives height above sea level, so when the terrain is 800 ft above sea level the plane would be 2000 ft above terrain when the altimeter is reading 2800 ft.

Some aircraft also have a radio altimeter that provides height above terrain, which would read 2000 ft in the same situation.

High enough to NOT hit your house. That’s how high! :slight_smile: