No, i don't think so... remember #5 "still alive?" perhaps the defunct robobrain ran amuck and got mid-evil on the Enclaves ass while still in the vertibird? hehe
Something tells me that a twister didn't cause the crash. I mean, it's possible... but i just don’t think so. But, really, i don't think there's any real reason... just a random occurrence, nothing more. They probably fell asleep at the wheel, or maybe the pilot was on his cell phone or maybe they were having a circle jerk and got a bit carried away? You know, the normal crap that causes wrecks.