The USAAF began building up its air forces in Europe using B-17Es soon after entering the war. The first Eighth Air Force units arrived in High Wycombe, England, on 12 May 1942, to form the 97th Bomb Group.
On 17 August 1942, 12 B-17Es of the 97th, with the lead aircraft piloted by Major Paul Tibbets and carrying Brigadier General Ira Eaker as an observer, were escorted by RAF Spitfires on the first USAAF raid over Europe, against railroad marshalling yards at Rouen-Sotteville in France, while a further six aircraft flew a diversionary raid along the French coast. The operation was a success, with only minor damage to two aircraft.
There was optimism that the guns on the Flying Fortresses would be enough to deter the German fighters. As Brigadier General Ira Eaker told the press afterwards:
Shortly after we turned back towards the Channel we began to get the action we had anticipated. Coming up fast out of the earth pattern below us I spied three Focke Wulf 190 fighter planes. As the first zoomed up towards our Flying Fortresses, it was not yet evident to me whether he was attacking our lead plane or our No.2 plane, directly astern of us and to starboard.
As he opened fire I realised he was aiming at No.2. his tracers seemed to burst wide of its left wing. After a few bursts at extreme range – perhaps 1000 yd. – he rolled over on his back and and went into a dive. The other two 190s attacked the rear plane of our flight. They opened fire from below; then an instant later they too pulled away at a considerable distance. I could see the bottom turret gunner of the attacked Fortress firing at them but I could not be certain that his bullets were taking effect though the tracers seemed very close.
When the last of the three 190’s broke off combat, I moved to the other side of the waist gunners’ station and observed at least a dozen puffs from exploding shells. They were deadly accurate as to altitude but several hundred yards to port. Meanwhile there was fighter activity overhead and to our rear. The RAF wing covering our withdrawal had climbed above us and passed somewhat astern as we left the target area.
Now they ran into some 35-40 enemy fighters which evidently had been reluctant to engage our Fortresses at close quarters. I can understand why. They had never seen our new B-17s before and the sight of the big guns bristling from every angle probably gave the Nazis ample reason to be wary.