Originally posted by dbarrym
It was an awesome building project, especially as he ended up building two - the first one crashed as well.
The model was pretty far out when it crashed; far enough that it was easy, especially with a white belly and silver topside, to lose visual orientation. One of the harder aspects of flying RC (comapred to full scale) is determining what way the model is going - towards or away makes a big difference in what control inputs you provide (yaw and roll are 'reversed' when the model is coming towards you).
For example, I have a large F-18C that is painted in a Marine "low viz" flat grey scheme. When it is moving fast (150-190 knots or so) it covers a lot of ground quickly, and scale-rate turns take a lot of room. When flying against low clouds or a hazy sky, there are numerous points in the turn where I can't tell which way it is going and just have to "put myself in the cockpit" and mentally fly it around, with no changes in control input, until it is fully visible again. A lot of new or inexperienced RC pilots can get caught out by this and panic, applying hurried control inputs, causing problems.
It didn't stall/spin; the B-52 pilot admits to 'pilot error' as the cause - basically he thought the plane was rolling one way and applied "opposite" (spoileron, actually), which was actually in the same direction as the roll off, which caused the roll rate to increase. Spoilerons can cause a nose drop (loss of lift) as well as roll, explaining the increasing bank and dive angle.
Something this big flies in a very scale-like manner and once the nose was 50+ degrees or so down, with the added complication of the roll rate, it was all over. Very much like the full scale B-52 that crashed while practicing for an airshow in Washington state a few years ago.