"Kyle Boatright" writes:
We flew commercial back to Atlanta yesterday from California after a
weeklong trip to San Francisco, Napa, and Yosemite. On the way home, I had
a window seat and was surprised on a couple of occasions at how close 1,000'
of vertical separation appears when you're looking out the window from seat
13A. When another airliner passes 1,000' right under you on a reciprocal
heading with a closing speed of over 1,000 mph, it looks CLOSE.

I got the chance to sit up front in a plane in the flight levels a few
weeks ago, and it looks really close from the front window too. :-)
Especially dramatic is when you have two planes, one 1000' above you,
and another 1000' below you, passing at almost exactly the same time.
It feels like you are threading a needle between the other two
planes...

Chris