Even if it doesn't crash outright, there are often too many other bugs with it. I was scraping hills in a low down drag out dogfight, and the next time I watched the film I was 500 feet over the water. YOu can fly through the ground, even. There's also an annoying bug where if you take any kind of single ping's worth of damage it kills your engine, oil, guns, wings, tail, and leaves your plane a piece of fuselage, then it continues to move it along its path as if you were fine. Same happens for other planes, too.
It's not just an outright crash sometimes.
Overall with all the many problems I've personally seen with old film not playing properly, it's often best to start over from scratch. and REVIEW REGULARLY as you go!