High Quality Content by WIKIPEDIA articles! Operation Tidal Wave was a strategic bombing mission executed by the American Air Forces in August 1943, during World War II intended to put nine Romanian oil refineries around Ploiesti "out of action." The mission was unsuccessful in that it resulted in "no curtailment of overall product output . In terms of loss of life, this mission was one of the costliest for the United States Army Air Forces (USAAF) in the European Theatre, accounting for the loss of 53 aircraft and 660 aircrewmen. The day that it took place is known as "Black Sunday." Five Medals of Honor and numerous Distinguished Service Crosses were awarded to Operation Tidal Wave crew members.