Apparently a Spitfire T9 just missed hitting a Cessna 340 in October 2021:
https://www.bbc.com/news/uk-england-...shire-61759596
Airprox report here:
https://www.airproxboard.org.uk/uplo...%202021220.pdf
The interesting bit of the article (for me) is this:
An Airprox Board report said neither aircraft was "equipped with any form of electronic conspicuity equipment".It added that both pilots were relying on their lookouts to detect aircraft.
Presenting this, otherwise correct, statement in this way implies that every aircraft should have FLARM or a different conspicuity tool on board. While I'm not against this, one of the challenges here is the wide variation in available bits of kit that do not all talk to each other. Some standardisation on this front might be useful.