Charlie Brown was a B-17 Flying Fortress pilot with the 379th Bomber Group at Kimbolton, England. His B-17 was called 'Ye Old Pub' and was in a terrible state, having been hit by flak and fighters. The compass was damaged and they were flying deeper over enemy territory instead of heading home to Kimbolton.
Aware that they had no idea where they were going, Franz waved at Charlie to turn 180 degrees. Franz escorted and guided the stricken plane to, and slightly over, the North Sea towards England. He then saluted Charlie Brown and turned away, back to Europe. When Franz landed he told the CO that the plane had been shot down over the sea, and never told the truth to anybody. Charlie Brown and the remains of his crew told all at their briefing, but were ordered never to talk about it.
When asked why he didn’t shoot them down, Stigler later said, “I didn’t have the heart to finish those brave men. I flew beside them for a long time. They were trying desperately to get home and I was going to let them do that. I could not have shot at them. It would have been the same as shooting at a man in a parachute.”