That's a little high, most high level bomb runs were in the mid-twenties to low-thirtys back then. Service ceiling for the B-24 was only about 28,000 feet, the B-17 was around 36,000 but it was rare for it to get up that high. Migrating swans have been spotted as high as about 30,000 feet. As I recall, the record altitude for a bird strike was a vulture somewhere around 37,000 feet, although it was likely carried up by an updraft or thunderstorm.I think we had a lot of Bombers then which operated at more like 45,000 feet on their Bombing Runs...
It was during some of these Daytime Bombing Runs in which Migrating Swans were noticed to be flying at 45,000 feet or even slightly higher elevations...something which previously had been undetected, since no one flew that high other than in some occasional experiments. Balloons of course could get a lot higher.
O God, not ANOTHER one! Well I'm not bidding, I have three already and the neighbors are starting to talk as it is. I'm DONE with them!