Earlier this year, a friend of mine went to Nova Scotia to look at a Murphy Yukon that was for sale. Not just any old Yukon, but one like this one, only with a radial engine:
He decided to buy it and so after a few circuits, since he had never flown an amphib before, he set off on the 2500 nm trip home. After less than half and hour, the engine started mis-firing and eventually the engine quit. Luckily, in the middle of the large forest that he was flying over, was a three-lane highway, with no traffic.
He pulled off a dead-stick landing and was able to roll to a lay-by, out of the way of the traffic. Not bad for his fourth landing in an amphib!
Next day, he and the engineer went back, checked it out and decided the engine was running sufficiently well to chance flying back to the departure point. The Mounties blocked the traffic on the highway and they took off!
I can't imagine the cops in England being so cooperative.
The problem turned out to be an issue with the mags, that only surfaced after about 30 minutes.