I've been reading this book lately called The Gods of Eden by William Bramley. In it, he makes a good case as to why there hasn't been more recovered crashed UFOs. I'd like to quote an excerpt below to see what you think. Now keep in mind the FAA statistics on aircraft accidents. I think it's something like one in a million craft have a catastrophic failure, making it one of the safest ways to travel. He goes on to give other figures which would amount to only about one crash every 125 years. Of course all of this is up to debate since we don't exactly know the amount of extraterrestrial craft being flown in our skies, but it definitely gives a picture into why we may not see downed UFOs very often.