Re. the above, I e-mailed the Airprox board in September about incident 2017036. The jist of what I said follows,
"The last comment re. the C42 using a traffic service "by some members" is not only impractical but normally refused (due workload) by Farn. East, plus the C525 wasn't using that frequency! Also as an instructor ,a traffic service is impossible because of constant interruptions and inability to maintain a constant heading and altitude.
I am appalled that a 240kt jet can be released to Class G and then run at high speed through one of the busiest training areas in the south east. It's worth pointing out that for GA "below", to infringe controlled airspace above is considered a grave error and there are a perfectly sensible STARs to follow into most of the airfields taking jet traffic. In Class G it's very much "see and be seen" and given most traffic is GA, any electronic assistance, such as TCAS/ATC etc is only a bonus"
I can't find the Airprox board reply but they failed to answer any of the above points and I had the impression that there shouldn't be a problem if we use the correct ATC, giving traffic service or higher and we equip the aircraft with an array of collision avoidance electronics. I also pointed out that I was an experienced FI/FE and without the C42 FI and a lot of luck we would have had another midair collision.