These videos document a bit of interesting and unfortunate acro history regarding the 450 Stearman. Interesting to watch the airplane flown this way, which nobody does these days - for good reason. Not hard to see how problems resulted. Below are some excerpted posts by others on this subject from another forum: Marion Cole used to do a triple vertical snap in his  Stearman. Yep, triple vertical snap....I asked him what speed did he use and he kind of chuckled and said ''real fast''!! Of course, back then all those guys were in their late 20's/early 30's............. Stearmans and R 985's were plentiful and new. Marion did say they tweaked the prop and governors and sometimes could get 3,000 rpm out of a 450. The blower section is a 10 to 1 drive ratio. Of course this did raise problems with the prop/engine combo r.e. gyroscopic loads on the propeller, case, and crankshaft. Rolly Cole's accident was either a blade sep or a rapid destruction of the engine causing it to come off and take part of the upper wing with it. Bill Adams later owned Marion's Stearman and died in a similar manner as Rolly Cole. I doubt Adams had the same engine as was originally in Marion's plane but it started to promote the idea that these things weren't break proof. Almost the same attitude was prevalent when the Pitts was king of the contests. Now the composite monoplane crowd thinks the same with their airplanes and so far airframe problems seem to be few and far between. Bill Adams crashed at Valpariaso IN after the prop came off during an airshow flight. Again the prop came off and went through the upper wing. There is a still photo of the airplane with the wing folded and the prop in one corner of the photo. Very poor quality but you can see the prop. I was told the crankshaft failed but don't know if this is correct. The 985 crank is pretty fragile looking considering the size and weight of the prop.