Railfan 233:Alright, it makes sence now. The Germans would use captured B-17s to get an accurate reading on speed and heading, since the Americans were using the same aircraft, to get AA fire even more accurate.
Actually, it's a little more than that... Using the captured Forts allowed the German aircrews an extra measure of passive defense in that, even if they were marked with German insignia (as most were), the shape of the aircraft was easily recognizable as a "Friendly" to both the American bomber crews and any escorting fighters and allowed them a longer time to "shadow" the formation than say, an FW-200 would...
You, as a aerial gunner or fighter pilot, can spot and ID a hostile from a far greater distance by its shape before you ever see what markings it has...