Depended on the point of the war, the target, and the effort expended on that target. Early on, only a few dozen then a few hundred. Take into account diversionary raids, mechanical aborts, and multiple waves going at the same area, and its gets a little interesting trying to pin down an exact number.
I always figured a 1944-45 "maximum effort" to consist of about 1,000 to 1,200 bombers and about 750-900 fighters between main effort, diversionary raids, fighter sweeps, initial escort, escort over target, withdrawal escort...
Aluminum overcast indeed
