Do you have any evidence to share which might suggest that GDPR treats private aircraft differently than ... literally everything else?
If not, why would we just not accept that GDPR treats aircraft exactly how it treats everything else? The law, as written, clearly offers no specific coverage or exemption for any types of vehicles.
> Please provide some evidence of your repeated claim that they're illegal in Europe
https://gdpr-info.eu/
What kind of evidence do you want exactly? This is crystal clear to anyone with the most basic understanding of the GDPR.