Contrails left by P-47 Thunderbolts of the 78th Fighter Group. Passed for publication 28 October 1943. Printed caption on reverse: 'Thunderbolts - the "Guardian Angels" of Flying Fortresses. Here are pictures of Thunderbolts P-47s, the famous American fighter planes, which escort Flying Fortresses on their daylight missions over Occupied Europe. Photo shows:- High in the English skies our American Thunderbolts - P-47s, make long contrails as they set off for another mission over Continental Europe. The planes are up about 15,000 feet, gaining altitude rapidly. The contrails - what airmen call vapor trails - are caused by the freezing low temperatures at that altitude - nearing sixty below at 30,000 feet many times. It is a typically cloudy English sky, and all our American Air Force men are quite familiar with it by now. U.S. Pool/SH/G. Keystone 55 & 56.'