Flying from Denver to Chicago this week, I noticed that the American Airlines flight was informing us about our altitude – in first decimal place of a foot!!! To put it in perspective, 0.3 feet is about 3.5 inches – think about the width of your palm.

What was the great need to put that level of precision? Certainly, that level of precision cannot be accurate. A airplane measures its altitude, if I understand correctly, by the pressure difference of the outside where it is and the ground pressure.

Admittedly, it is a little more complicated than that – it has to understand what the local pressure at ground level of various points on earth are – regardless, it is a fairly inexact process. This is not your Sonar or Lidar technology at work.

Not to mention that to maintain that height constantly, the airplane would have to bounce around a lot depending on what is there in the ground below – you know a ditch here and a curb there…

I was thinking of asking American Airlines about it but was afraid they might ask me to “Depress” some button to get the accurate altitude 🙂 🙂