My '61 Chevy lost a fan blade while I was humming along and I thought I had busted a flywheel or worse. I quickly stopped and after going over everything, couldn't find the source of the problem and restarted the engine and the wobble was severe. I went back under the hood (on the side of the road) and discovered a fanblade embedded in the inner fender just behind the battery. Thrown in like an Ed Ames tomahawk toss...whomp! It was 2/3rds of the way through the inner fender and looked just like an axe into a tree. Wowzers.
I worked, pried, and metal fatigued and finally broke off the opposite blade to get it balanced again and drove another 800 miles home before hitting the boneyard for a new fan blade. That was 32 years ago. My how time flies...and so do fanblades. Better into the inner fender than through the hood.
I never moved the fanblade and it was still there when I sold the car a year or so later.
Yes they can and do let go. The scary part for me was thinking about all the times I had hung over the radiator working on stuff and revving the throttle.
A mechanic friend saw me doing that one day (before the fanblade broke) and explained to NEVER stand in front of a car while working on a running motor. He showed me some ugly scars on his legs where he was mashed into the back wall of the garage by a car he was working on when it slipped into gear and then used his legs as a cushion to soften the impact into the back wall of the garage. In his case it was a stack of tools, parts, steel, and other odds and ends the tend accumulate around the garage walls. They were all embedded into the back of his (also broken) legs.
