Probably this: * https://www.cbc.ca/news/canada/british-columbia/pemberton-b-c-mid-air-crash-caused-by-blind-spot-tsb-1.2770887 https://www.cbc.ca/news/canada/

Probably this: * https://www.cbc.ca/news/canada/british-columbia/pemberton-b-c-mid-air-crash-caused-by-blind-spot-tsb-1.2770887 https://www.cbc.ca/news/canada/british-columbia/pemberton-b-... Whenever there is a collision involving light aircraft the question of anti-collision systems comes up. Unfortunately the powers that be have completely failed to come up with a workable standard for such aircraft. The glider people eventually just gave up on waiting and now use a proprietary system called FLARM which has fairly good adoption. There is more than one system of that type available for light powered aircraft with not very good adoption. Each system is entirely incompatible with each other, including the standardized ones used in heavy commercial aviation.