Once the engine had fallen from the wing, he said, the only flames were coming from a broken fuel line, the wind pushing the flames towards the rear of the aircraft, "like a blowtorch." They were no danger while the plane was in the air, but once it landed they spread to the fuselage - and the 707 came to a halt on the far side of Heathrow from the waiting fire appliances.
By the time Mrs Duncan fled the plane the oxygen bottles stored beneath the passenger compartment began to explode, the floor collapsing and the stewardess and four passengers falling into the fire.
All that was needed, Mr Ellis added, was for the crew to pull the handle that would have cut the fuel supply to the broken line, and so starved the flames. The plane itself had not been on fire until it came to a halt on the ground.
The flight engineer had "got it in the neck" for not taking that action, he said, adding that no one should have died.
"If the proper procedure had been followed Captain Taylor would have completed a three-engine landing, as all pilots were trained to do, and everyone would have survived," he added.
"It was a remarkable piece of flying buy a hell of a disaster that should not have happened."