OzSync:
The offical FAI world record for an electric model is 4539m/14,892ft (set by Gian Aghem in 1995)
The offical FAI world record for an IC model is 8205m/26,919ft (set by Maynard Hill in 1970)
Seems many of todays RC models have cameras installed, similar to drones? Check Youtube, dozens of film clips from RC models - this seems to be one?
Potentially drones and RC models could be a safety problem but haven't been so far.