There's a few mods out there now for IL2. We (the NZ IL2 community) have settled on a particular mod that provides things such as radar, moving map objects (ie ground forces can capture airfields and if you want it back you need to destroy them) and enhanced sounds.
A particular sound mod made by Tiger33 (details here) focusses on the fly-by sound. I made a 1 min video to demonstrate it, thought some here may be interested to hear (although YouTube does mess with the audio quality a bit)



