All planes can do a barrel roll. When executed properly a barrel roll is a 1g maneuver. At no point during a barrel roll should a plane experience any forces significantly different to level flight.

The largest plan to ever be barrel rolled was a Concorde prototype.

This is the craziest Wikipedia article I've read in a while.

Feel sad for the dudes mental health state, but damn, what a way to go. A well executed barrel roll in a q400, seemingly without prior flight experience. Wild.

Still reading the article, but I felt compled to comment on the level of detail:

Both [fighter jets] [...] reached supersonic speeds, which generated sonic booms on the way to the Puget Sound area. [emphasis added]

Are these sonic booms relevant to the actual incident? Probably not. But the author decided it was part of the events and decided to include it and I find that endearing.