What was the total number of US aircraft used in world war 2?
Although the actual number of all aircraft may not be accurate,
it might be easier to break it down by type of aircraft. For
instance over 12,731 B-17s of all variants were produced from
1937-1945. Total US aircraft losses exceeded 45,000 aircraft. Also,
check here: http://www.world-war-2.info/statistics/, specifically
the chart fourth to the bottom.