A helicopter pilot dragged his semi-conscious passenger to shore after crashing in crocodile-infested mudflats near Darwin last night, then buried the man in sand up to his neck to protect him from hypothermia.

The two men were camping at a remote spot near Dundee Beach, about 50 kilometres south-west of Darwin, over the weekend when they decided to take a flight in their helicopter about 6pm yesterday.

Helicopter crash ... a passenger lies buried in the sand as emergency services come to his rescue. Credit:NRMA CareFlight

After spotting a crocodile from the sky the pair got into trouble when their helicopter crashed as they were trying to get a closer look.

"They decided to go for a flight in a single engine two-seater Robinson - the sort of thing used for cattle mustering," said NRMA CareFlight director Ian Badham.