The Allied effort in the European Theater of Operations relied upon thousands of bombers to help weaken the Axis ability to make war. Thousands of bombers require thousands of crews and heavily armed aircraft such as the B-17, B-24, Lancaster, and others, needed well trained gunners to defend against Nazi fighters. Normal training involved aircraft towing targets and gunners in other aircraft shooting at the targets. To train the number of crews necessary, at least half of the aircraft in Europe would have been needed back in the States. The consumption of fuel, ammunition, and other concerns such as accidents causing loss of life and equipment would have been staggering. Fred Waller, working entirely alone, solved these problems and provided for better training in the bargain.