1943: In this operation, 177 B-24 Liberators from the Ninth Air Force flew staging from Libya flew low-level routes to drop 311 tons of bombs on the Ploesti Oil Refinery in Romania. This was the first large-scale, minimum-altitude attack against a strongly defended target, and the longest major bombing mission from base to target undertaken to date. Fifty-four planes and 532 aircrew were lost during the mission.