There’s an amphibious aeroplane parked on a high-altitude lake in Kenya. It flew in ok, but was unable to get out as the air was too thin. The natives used it for domestic purposes such as shelter etc. I don’t know if any of it remains but it was probably in the 1950s.
A good friend of mine worked for an oil company there and related what he saw. The craft made multiple attempts to take off but each time ran out of “runway”.