During the Second World War, the Royal Air Force of the U.K. had exceptionally brave pilots. They took out their Avro Lancaster bombers, went deep into enemy territory and bombed, despite heavy German ground-to-air gunfire. The planes took multiple hits, sustained bullet holes, but most made their way back to the airbase. The battle-hardened, brave-heart pilots and their aircraft shared an unusual bond; human emotions and reinforced steel glued in a do-or-die unseen tether of fait accompli.
After months of carefully studying the aircraft, looking at the distribution of the bullet holes, the service engineers could see a pattern emerge. The German gunfire damage was more discernible around the wingtips and the fuselage, while the wing-base, cockpit and engine bay remained relatively unharmed. They came up with a novel idea of strengthening those areas by bolstering them with a strong layer of lightweight bulletproof metal.
Abraham Wald, a statistician, was called in for a second opinion. Wald was a Jewish Hungarian, who fled Nazi-occupied Austria, to join the allied forces. He studied the aircraft and came up with a diametrically opposite opinion.
