Ok we all do know that every now and then an occasional plane crash occurs in San Andreas. Jordan from PlanetGTA has written a nice article on this topic. He teaches you how to easily find this mysterious crashes and there is an interesting bit on how plane crashes got into the final game.
"Planes, like the rest of San Andreas, are drawn around CJ as he moves through the state. In Los Santos, you'll see high-flying commercial jets thousands of feet in the air. On the beaches of Santa Marina, there might be the occasional flyby of a biplane. Out in the country, smaller private aircraft are constantly buzzing around. When we first implemented the feature, we found that every once in a while a plane would spawn with a trajectory that led it directly into the side of a mountain or right into the ground. And we loved it, so it stayed."
- Craig Filshie, Rockstar Games
Click here to read the preview. You can also download several plane crash videos and even submit your own!