A group of B-17 Flying Fortresses of the 95th Bomb Group are refueled up for a raid The tail of a B-17 (serial number 42-5280) is in the background. Printed caption on reverse: 'Giants Of The Air. The big day raid on Germany this week has once again proved the efficiency of the Flying Fortress. Here is the latest type to be in action. F.11519. Getting fueled up at an army air base are these giant Boeing Flying Fortresses. Characteristic of the craft is this giant dorsal fin, which gives it extreme stability in flight, enabling greater bombing accuracy. S.&.G. B.E.' On reverse: Sport & General Press Agency, US Army Press Censor E.T.O. and US Army General Section Press & Censorship Bureau [Stamps].