Landed in lax
So I just took a flight that literally just landed at lax. And it had one of those information screens showing our location on a map. This included speed and altitude.
Should I be concerned that when we touched down, the screen said we were at 100 feet?
It depends on how they measured it.
There are two ways for a plane to read their altitude:
* Directly with some kind of fancy radar.
* Estimating, by measuring the outside air pressure and comparing it with a reference value. The higher up you go, the less air pressure there is.
This latter method is what is commonly used for flights: the plane is not exactly at 33000 feet cruising, but “is flying at the height where the outside pressure is value X.”.
The cockpit instruments switch from estimating to the direct measurements at a certain height (that is, when it is landing or taking off)
It sounds like your in-flight info screen didn’t make that switch.
Comment by Scott — January 10, 2008 @ 4:42 pm
Hi Will! Happy New Year. :)
Kinda freaky that the screen wasn’t accurate… good thing it wasn’t what the pilot was relying on.
Comment by suzanne — January 15, 2008 @ 12:10 pm