Video report by Matthew Taylor.
Rescuers in the Lake District are warning drone pilots to fly sensibly after they had to avoid a collision between a drone and a rescue helicopter.
The Cockermouth Mountain Rescue team say it was a 'scary moment' which could have ended in disaster.
The casualty, with a serious medical condition, was going to be winched off the mountain side when a drone was seen by one of the rescuers.
The fear was that if they drone got too near the helicopter it could have damaged its blades or even got sucked into a helicopter's air intake.
It's one of several incidents emergency services have been dealing with recently.
Richard Greenwood, from Cockermouth Mountain Rescue, said: "The drone was at quite an altitude. It was off to the side of the helicopter, and what we were concerned about was that if they turned into the valley where the drone was then that could have been a problem.But they were able to continue and pretty quickly, we were able to confirm that the drone was behind and above them."
The Civil Aviation Authority deals with drone flying and they say the rules are quite clear for people wanting to fly them.
Jonathan Nicholson said: "They are sharing the airspace with other users and they have the responsibility to be safe and do the right thing. But in reality it's much easier for a drone user to see, spot and avoid something like a helicopter than it is the helicopter pilot.
"The responsibility is on the drone operator to do the right thing, especially if it is an emergency service helicopter."
Meanwhile, there has been another incident of inconsiderate parking blocking emergency services.
Rescuers couldn't get to a capsized canoe to help two people in the water as Wastwater. Fortunately they managed to get get out unharmed.