That is because the cause for each of the crashes was somewhat the same.

The Buff did not use regular ailerons, as you would normally think of
them. The flexibility of the wing would twist when a normal aileron input
was applied, and would actually give the opposite roll reaction that was
expected. The aileron was acting like a boost tab, in sorts.

The solution was to control roll by having a spoiler instead of an
aileron, so that if you wanted to roll right, the right spoiler went up,
that side lost some lift, and the aircraft rolls. It was also good to
prevent adverse yaw.

The only problem with that type of control roll, was that if a critical
bank angle was exceeded, the roll was unrecoverable. Your were going to
crash, period.

The full sized crash was being piloted by a senior pilot who was known as
a cowboy, and exceeded various flight parameters, frequently. Some crew
would not fly with him. He pulled his steep bank trick one too many
times, and did not get away with it.

The RC model might have gotten too steep, in a normal flight pattern, but
I think what happened was that the overcast sky messed up the pilot's
orientation clues, and he banked steeper, rather that flattening it out.
I've done it, and about anyone who flies RC has also done it, and gotten
it back into control. With the model Buff, getting that steep put you
into an unrecoverable area of the flight envelope. Boom, was the final
result.
--
Jim in NC
Thanks Jim, for the explanation of the Buff's flight characteristics. I was
well aware of the reputation of the pilot. There are numerous cases of the
pilot in control killing their crews by doing what they shouldn't. I always
kept that in mind when the pilots I flew with exceeded my comfort zone. Fly
safe.

Rob