Gwynge wrote:Four in the last 20 years it seems:
https://en.wikipedia.org/wiki/List_of_mid-air_collisions_and_incidents_in_the_United_Kingdom#2010s
I guess by the time you get to the 6th or 7th cause you're into the not-very-likely territory, the 8th cause being finding a black and white cat stuck under the pedals.
People seem to get very excited by the possibility but there's still more chance of being run over by a man in his 40s driving a red landrover on the way to the airfield )
Unfortunately that list is not complete nor comprehensive. I suspect there are more GA collisions than listed.
From BGA statistics there have been 9 glider:glider mid-air collisions in the 13 years since FLARM was introduced in the UK, only one of which occurred between gliders that were both carrying FLARM (the company did a thorough investigation but couldn't reach a definitive conclusion).
There were no glider-glider collisions in 2015, 2016, 2017 - the first clear run of more than two years in BGA records, though this could be a statistical fluke. There were 5 collisions between gliders and tugs or tow-ropes in the last 13 years (all where Flarm was not installed in both aircraft).
In addition I am aware of two (fatal) glider:powered aircraft collisions in the last few years, only one of which is listed on the wikipedia list.
Note that of the 19 collisions since 1998, 7 fatalities resulted. The rest either resulted in a successful bail-out or landed with damage.
Statistically MAC is relatively rare, thankfully. From 10 years with Flarm I can't say it has saved me from a collision, but I can say that every 20-30hrs or so of flying it prevents a "s****! that was close" moment.
Of course the nature of gliding is that we get a lot closer to each other. I want to stay much clearer of non-glider traffic and I would feel much more comfortable if I could avoid a few "that's a bit too close" moments with things with engines as well.
The BGA publishes detailed annual accident analysis (see below for an example), which has some historical trends:
https://members.gliding.co.uk/wp-content/uploads/sites/3/2018/03/Accident-review-2017-v2.pdf