Martin X. Moleski, SJ wrote:
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.


This issue is not aircraft that the operator can see. A UAV may
operate beyond line of sight of the operator. I think the Transport
Canada document mentions something about the operators satisfying TC as
to out-of-sight procedures.



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.

In actual fact, in clear weather is is not that difficult to spot RC
aircraft from a "real" Cessna, either... so long as the RC aircraft is
below. I have wandered over an RC field at 1000 AGL without realizing
it... and was amazed that there were aircraft "so far" below me, until
I realized they were RC.

It might be a little more difficult to spot them at the same altitude.


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.

I don't know if Farmers are going to line up to get an aerial view of
160 acre plots. They can walk that. Especially if they have to go the
the middle of it anyway, to set up the flight. This technology might
be useful for those farms of several thousand acres... miles across.
Where the operators will not necessarily have their aircraft in sight.

But the point remains.... I am not yet convinced that they will be able
to fly these below 2200 feet without complying with the Transport
Canada's UAV requirements, whatever those may be.