On Sun, 30 Jul 2006 08:28:06 -0500, "Jim Macklin"
wrote in
Mt2zg.84637$ZW3.19317@dukeread04::

You do clearing turns, shallow turns and you look for other
airplanes. Airplanes at your altitude look to be on the
horizon, airplanes above you are above the horizon and
airplanes below you are below the horizon and are harder to
see because of the ground. But you look for moving shadows
on the ground at low altitude. You run all you lights and
hope the other guy is also. You look out the windows. You
look for small dark spots that don't seem to move because
things on a collision course have zero relative motion.

But the human eye seems motion better than it does small
dark spots.

In areas of high traffic, there are often radio procedures
used to announce intentions. There are IR detectors that
can "see" the strobe lights on an airplane and they do have
systems that can detect the transponder of other aircraft.
And they are developing data-link systems that will put a
ground based radar display in the cockpit of those airplanes
and countries that can afford the cost.

Military flights, though exempt from FAR § 91.117's 250 knot maximum
speed restriction below 10,000', do not detect Mode C transponder
beacons (no TCAS).


[rec.aviation.military added]