Ground personnel of the French Air Force work on P-47 Thunderbolts including (13, serial number 42-25829). Printed caption on reverse: '53600 A.C. - Thirteen is an unlucky number for the Germans. Between missions, while pilots eat and are briefed, mechanics and armorers swarm over these P-47 Thunderbolt fighter-bombers flown by a famous French squadron. The plane at left, although it bears AAF insignia, is assigned o the French unit and is flown by a French pilot. U.S. Air Force Photo.' On reverse: U.S. Air Force Photo Detachment-5 HQ AAVS (MAC) [Stamp].