Originally Posted by
ChickenHouse
ADS-B In/Out could serve perfectly, if not better, than Flarm, BUT physics comes right at the corner. The US already had to introduce UAT to free available bandwidth from 1090ES and if we really would all go for an ADS-B 1090ES solution, the gibberish of all that stations will congest the air. Flarm did overcome some of the restrictions by reducing power, so making the area covered "fit for purpose of the gliders". Now with the new PowerFlarm the advantage gets less ... Same trouble as with radios, as long as we all had 3 to 5 Watts of power, we could reach the next airport and traffic control, now we blow our stumbling with 16 Watts from final in Birmingham to the Orkneys.
Take your point about ADS-B in/out do not think this would be much of a problem as long as the system used mainly warns of imminent collision, which is thankfully very rare. That is why I much prefer some sort of audible warning of a potential collision rather than the virtual radar display being promoted by many. You really do not need to know about all the aircraft near you- only about the ones that are likely to hit you!
PowerFLARM does this with ADS-B and other FLARM/PowerFLARM transmitters but only indicates the close presence of Transponder equipped aircraft (if transponder switched on!). Not sure about PilotAware.
So ADS-B in/out would be much better but is still pretty expensive (and not widely adopted by light aircraft).
In the meantime, I think PowerFLARM is the best solution (or possibly PilotAware), despite the cost. What price do you put on reducing the risk of a probably fatal mid-air collision?
PS Any system that detects ADS-B is better than nothing because nearly all airliners have it. Can you imagine the consequences for GA in the UK if a light aircraft, microlight, gyro, helicopter or glider were to pile into an airliner?