Yuliy Gerchikov wrote:

Now, if only all Hawkers were *coming* from a very well defined -- and known
in advance -- point in space (as pitcher's throw is defined by human body
mechanics), and *going* into a similarly well defined box in space, our job
would be easy.

No, it wouldn't be "easy" -- it also wouldn't be as difficult as has
been claimed. The problem may be that we have not separated the
process into its constituent parts: 1) find the traffic; 2) avoid the
traffic. Finding the traffic is the most difficult. Avoiding it depends
on finding it before it gets so close that you don't have time to avoid.

The only traffic you must be concerned with is that which is "going
into a similarly well defined box in space" -- your aircraft. Your
cockpit is the batters box, the plate is all of your aircraft which you
must protect, to continue the baseball analogy (probably overworked by now).

So how are we going to find the traffic in time to avoid it? In ALL
cases, by using our eyes. Whether we are initially alerted by some
electronic tool, a radio message, another crew member, or by our own
visual scan, we still must have acquired the traffic visually before we
can determine the proper response. The exception to this today is TCAS,
which is currently beyond our reach.

With the availability of inexpensive PCAS devices, the complaints about
the steep cost/benefit ratio of any proposed transponder mandate are
less convincing. If all aircraft carry operating mode-C transponders
_and_ PCAS/TCAS devices, then virtually all aircraft posing a potential
collision hazard will be identifiable to all other aircraft.


I assume you have already found out that you can hear a powered
aircraft from the cockpit of your glider.

Nope -- never been close enough, I guess. I doubt it, however, given that
(1) bizjets are amazingly quiet, (2) bizjets descending at flight idle are
quieter yet, and (3) the wind noise is very noticeable even in the best of
the modern gliders. So I would not rely on hearing.

For a guy who has never been close enough to hear another aircraft (or
is it only a bizjet?), you are very sensitive to the possibility of a
midair. Would that more people were. I wouldn't know about "modern
gliders", but from the cockpit of my 1-26, a type not noted for its
inherent silence, I can sometimes hear other gliders with whom I share a
thermal. Mentioning sound doesn't mean that I expect it to be a useful
collision avoidance device, however.

If we identify which phase of the traffic avoidance problem we are
addressing, we will probably find we have very few points of disagreement.


Jack