I believe with a SkyEcho (ADS-B IN/OUT) device £600 a tablet and SkyDemon you have a TCS device for as little as £1000 with all the benefits of skydemon. Then as long as everyone runs mode S we would all see each other and reduce these sad events happening. This is UK CAA Approved only. Even gliders could run this, has an internal batteries that runs for 6 hour.
SkyEcho ? uAvionix
It would appear from the tracks they where both on the same track and the 152 descended onto the helicopter so in each others blind spot very sad day.