The operation was to consist of 178 bombers with a total of 1,751 aircrew, one of the largest commitments of American heavy bombers and crewmen up to that time. The planes were to fly from airfields near Benghazi, Libya. They were to cross the Mediterranean and the Adriatic Sea, pass near the island of Corfu, cross over the Pindus Mountains in Albania, cross southern Yugoslavia, enter southwestern Romania, and turn east toward Ploiești. Reaching Ploiești, they were to locate pre-determined checkpoints, approach their targets from the north, and strike all targets simultaneously.