In the case of a plane crash, it's caused by human effort. A plane crash is much deadlier, so we regulate airplanes and pilots way more than we regulate cars and drivers and force it to be less common.

This isn't a universal law by any means, but most of the time it's true it will either be confirmation bias, normalcy bias, or a case of humans forcing it to be true because extremely common horrible things aren't good.

It's also caused by how you construct the question. Pairing plane crashes and car crashes together is completely arbitrary. I could pair watching a movie (a common experience that elicits a strong emotion) with watching the paint dry (something extremely boring that I never do). I could pair going on a run every day (which gets my heart and lungs pumping) with going on a plane ride (which is honestly pretty boring). But there's no real reason for me to do that, I'm just creating whatever picture I want.