Denti: Spot on.
gpn01: if all traffic was required was to have a Mode 3 or a Mode S transponder then they WOULD be visible thereby increasing visibility and enhancing Flight Safety....isn't that what we'd ALL like....an increase in flight safety?
(3) Mode-S doen't provide autonomous interoperability as it requires either TCAS to be also fitted or to be in contact with ATC (and not all gliders have radios). Trials have taken place in Europe with gliders using FLARM, which is a GPS-based collision avoidance system which gives you warning of all potential collision risks with other suitably equipped aircraft and overcomes the need for a controller to be monitoring traffic.
Only one of the aircraft involved needs to have TCAS fitted, it's clever enough to give Traffic Advisories and Resolution Alerts against all Mode 3 squwakers be they mode S equipped or not. The controller isn't even necessary in that.
(5) Does anybody have proof that having a transmitter constantly broadcasting within a few feet of you doesn't have any effect on your body ? The effect of long term exposure to magnetic/radio transmissions still isn't fully understood. And before anybody says "oh but we all use mobiles and they're ok", I'd suggest doing some proper research1
Straws....clutching at............?
Let's try the situation from a different perspective:
"What effect do you think a mid-air with a commercial aircraft flying in uncontrolled airspace, where it is well known that not all traffic cannot be seen, is going to have on commercial operations?"
Not all "commerial" aircraft are passenger carrying air transport operations. In my job (on both types that I fly) we have GOT to operate outside CAS at all levels in order to get the task done. We are a civilian company with an AOC and therefore technically a "commercial" operation.
Sorry glider guys, there are no arguments that will stand up against the Flight Safety issue. The only other option will be to increase the amount of CAS around airfields, lower the base level of en-route sectors and make it illegal for you to operate above a certain level.....without a Transponder i'd suggest 2000 feet would be a good altitude cap.