In August 1944 Eighth Air Force replaced its provisional weather reconnaissance units with permanent ones and the 652d was activated. The 652d primarily flew B-17Gs, although at first it also had B-24Ds and B-24Hs. Its missions were long-range weather flights code named "Epicure" In which the aircraft flew a box pattern 700 miles out over the Atlantic. Weather readings were taken every 50 miles at heights varying from 50 to 30,000 feet. The average flight time for these flights was over 12 hours. For thirteen months the squadron maintained an average of 1.5 aircraft in the air over the Atlantic at all hours of the day and night, and for the last nine months of the war the average exceeded two aircraft in the air for all hours of the day and night.