No-one was thought to be badly injured but an eyewitness said the pilot was dragged away from the plane by his co-pilot shortly before the aircraft burst into flames.
Philip Makanna, from San Francisco, dragged the pilot to safety before returning to the burning wreckage to salvage his cameras.
Mr Makanna was the back-seat passenger in a World War II American training aircraft that crashed on take-off at the Imperial War Museum, at Duxford, in Cambridgeshire.
He climbed out of the smouldering plane and pulled the unconscious pilot, Clive Denney, from the cockpit.
Mr Makanna lay the pilot, from Essex, on the grass and as the plane burst into flames, rushed back for his cameras.
Both pilot and passenger escaped without being seriously hurt.
A spokesman for the Imperial War Museum said the aircraft was a two-seater World War II American trainer.
It was not scheduled to take part in the Flying Legends air show on Saturday and Sunday.
No-one was thought to be badly injured but an eyewitness said the pilot was dragged away from the plane by his co-pilot shortly before the aircraft burst into flames.
"It was quite dramatic. It seemed that the pilot couldn't get out and the man behind pulled him clear and then he limped away.
"Very shortly afterwards the plane burst into flames," the onlooker said.
The T6 Harvard crashed as journalists were gathering to interview veteran fliers, who will be guests of honour at the event.
The accident comes a month after three people were killed in two air crashes during a flying show at Biggin Hill in Kent.
But the museum spokesman said he was satisfied with the airshow's safety preparations.
"Safety is always our first priority and that will be the same this weekend.
Safety record
"We are not stepping up precautions in any way as a result of what happened at Biggin Hill because we don't feel that is necessary.
"Our safety record is very good at Duxford."
During the past five years one pilot has died after crashing during an air show at Duxford.
The venue stages an annual series of flying shows each summer and has planes flying on a daily basis.