>>64442707
Just as unsustainable as the engines. The US cycled their pilots back to train recruits, imparting their experience on the next generation, therefore accumulating institutional experience and raising the floor of new pilots. The Luftwaffle had to live in a "target rich environment" (also known as losing hard) and kept their pilots in service until they died. This meant rookies either were naturals and learned by the book, or were eliminated quickly. Either way, experience (and men, machines) went wasted.
Sure, you got a number of pilots who survived quite a long while and racked up impressive numbers due to being thrown into the fire again and again, but in a total war, a handful of exceptional pilots aren't worth more than their propaganda value. And propaganda you can print more of. Exceptional talent is irreplaceable.