I never met Bud Meade. I made contact with him first for research for Heavier Than Air, wanting to know what it was like to fly in machines more substantial than the models I made when I was a child.

Bud was a ball-turret gunner on a B-17 in World War Two. Bud was going to come to the opening of the exhibition as the guest of honour, but he died on the 19th of August 2002 at the age of 78. So I won't meet him now.

What was it like? What would he have told you? Bud was 18 when he joined the American Air Force, and as the youngest and slightest of the crew to which he was eventually assigned. He 'rode ball'; none of the others were willing to do so. In May of 1943 Bud's B-17 took off as one of 400 planes whose intended target was the U-Boat pens of Wilhemshaven.

It took almost three minutes for Bud to work his way into the ball turret; it always did; it took at least as long to extricate himself at the end of a sortie. The space was confined, formfitting; once you were in you were in for good, that's how it felt, and once you were in there were communications, an air supply, and the electrically heated suit to plug in too. Then he was ready.

Outside the aircraft, but inside too; his view of the ground was uninterrupted. Bud was able to watch the bombs as they fell away, or the graceful curves of his tracers as he squeezed the triggers and the violent airbursts as they flew through flak. Bud did not like flack, it made him nervous, but he told me that he felt protected in his alloy and perspex blister against anything but a direct hit - but then Bud, at the time, was eighteen, indestructible.

The defenses for the U-boat pens were heavy; within minutes of commencing its final approach, Bud's B-17 had lost two engines and the third was on fire. The pilot tried to jettison the bombs, but the bomb bay doors were jammed. The plane lost twenty thousand feet before leveling out eight thousand feet above the ground; the pilot ordered everyone to bail out. But the doors to Bud's ball turret were jammed as well. He watched as his friends' parachutes bloomed beneath him, and felt the plane descend

Bud tried to make me understand what ran through his mind at that moment. I imagined but imagining is easy. He talked about a kind of resignation; as the plane fell, as the ground beneath him flashed and sputtered, as the flak rose, as other damaged bombers peeled off. When the door above him opened he was astonished; Staff Sergeant Charles Huber had stayed on board, cleared the debris that had blocked Bud's exit, and freed him. Huber helped Bud into his parachute and threw him off the plane, but didn't jump himself; there were two others still on board that he was trying to help.