On Sat, 29 Jul 2006 15:16:27 GMT, Jose wrote in
:

The operators probably have to eyeball the airspace over the
160 acres being photographed. [...]
They ought to be able to see full-scale aircraft entering the
airspace and command the UAV to descend or change
course to avoid the traffic.

How reliably can you eyeball 160 acres and see all aircraft in time to
descend or change course?

Sufficiently to avoid mid-airs.

I fly RC about four or five miles away from Niagara Falls
International Airport (IAG), which hosts a reserve air base
on the other side.

We get lots of planes of all sizes over or near our field.

I don't think it would hard to see and avoid full-scale traffic
approaching a 160-acre site.

How often have you not seen traffic called
out to you by ATC?

Not applicable. The few hours I've spent in a Cessna
172 as a passenger are surely not enough to answer
your question.

How long does it take for you to find traffic in the
pattern when you come in to a new airport to land? Do you find it all?

Same reply.

I'm speaking from hundreds of hours of watching RC planes
and local air traffic from the ground.

The operators will not
want to have mid-airs any more than other pilots.

If the operator has a midair, he gets a reprimand. If a pilot has a
midair, he dies.

The main burden of seeing and avoiding has to be on
the ground operator. The odds of a pilot seeing a UAV
of the size proposed for the aerial photography are miniscule--let
alone recognizing it as a threat and avoiding it.

Marty