[rammjaeger]

Even after year-long research nobody will be able to answer this question comprehensive. The answer requires a complete list of some thousand surviving German WWI pilots. Then it is necessary to research all with the intend to find the members of the NSDAP. Or you are doing that the other way around - look at the files with millions of members of the NSDAP and try to find all aviators or pilots. This research can fill some years - or lifes?

An easier approach is to list a sample like the holders of the Pour le Mérite.
Who was a pilot? Who did survive? Who is known to be a member of the NSDAP?

And this can be very misleading - because human beings are very different, as well as the motives to join the party. I know enough cases if non-members were worse Nazis than members of the NSDAP.
In general many former pilots joined because they hoped for a revenge after WWI and the reconquest of the lost territory.