Flarm would also have almost certainly helped avoid this, but GA is apparently largely in ignorance of it or resolutely against fitting it, even though many GA pilots continually complain about gliders being a collision hazard, and UK gliders are getting Flarm in increasing numbers.
(Unlike PCAS, Flarm alerts when a collision is likely i.e. converging tracks, not just another unit in the vicinity which may not be a threat; and it shows the direction of the threat. It does not alert nearby but not converging track units.)
Same arguments as PCAS re wires etc., however – it would for most people be a portable piece of equipment, needing a battery supply or lead to a lighter socket or something.
As I have posted several times before, GA power/power collisions are more frequent than GA/CAT (civil air transport - thankfully none yet in the UK) or unrelated power/glider (only about 4 in the last 30 years).
Regarding wider use of FLARM, my personal opinion is that for the UK, use by gliders will increase slowly from a few per cent to a significant proportion, when the critical mass will be perceived as being large enough to encourage most glider pilots to use it. Unless something better comes along for powered GA, I think it quite possible that the same thing would happen, with the timing a few years later. I suspect that the middle phase, rapid increase in use once a critical mass is reached, will happen because those without will be shown how many more aircraft they can’t see that are in fact detectable. Just my opinion.
see
Flarm - Homepage
(No commercial relationship with Flarm, just a customer).
Chris N.