The use of agricultural aircraft for firefighting continued to increase. A 1956 report from the USDA Forest Service documented its effectiveness. In 1956 following the success of Willows Flying Service’s Stearman for firefighting, six more agricultural aircraft were converted to air tankers in California. These aircraft became the Willows Air Tanker Squadron and were a critical part of the firefighting force there. These aircraft, piloted by agricultural aviators from northern California, dumped 83,000 gallons of water and 66,000 gallons of fire retardant on 25 different fires. In 1957 the squadron expanded from seven to 12 aircraft and their success began to inspire other states to start their own aerial firefighting programs. By 1959 the aerial firefighting industry was well on its way.