On 6/9/2012 11:50 AM, db_sonic wrote:


Vaughn

Could good "old" PCAS help in this situation assuming both gliders
have transponders and are being interrogated.
And for that matter the one at AirSailing (hopefully we will find out
if they had this equipment). It too is far from perfect but the alert
it gives never fails to get my attention and elevates scan to the top
priority of my pilot load(or equal with flying the plane).

This situation may be the worst possible: the high glider is behind the
low glider, and neither can see the other. Possibly, the upper glider's
fuselage blocks the Flarm signals in both directions. PCAS might provide
a notification that the other glider was present (if at least one glider
had a transponder and the other the PCAS), as the glider positioning
would not interfere with transponder signals.

Still, a PCAS system would not warn you that a collision was imminent,
as it can not detect what appeared to happen: a quick pull up, perhaps
triggered by hitting some lift. How often do we do that, without
checking behind and above first? I do it a lot as I travel along under a
cloud street, and I know others also do it.

Maybe we need a mirror positioned to easily see that blind spot.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)