Throughout the series the standard B-17F version is shown, but by early 1944 nearly all B-17s in the European Theatre had been upgraded to the B-17G version with the distinctive powered twin nose turret to help combat frontal assaults by the Luftwaffe.
1st Lt. Curtis R. Biddick, played by actor Barry Keoghan, was born in Livingston, Wisconsin, not New York as portrayed in the series.