Boeing Barrel Roll

Test pilot Tex Johnston shows off the capabilities of Boeing's new 367-80 "Dash 80" prototype -- which would later become the Boeing 707 -- at a 1955 air show. The barrel roll (or aileron roll to others), done twice, was a no-hazard 1G maneuver for the Dash 80, but thoroughly impressed the crowd. Following the roll, it's said that William Allen turned to an elderly attender to ask for heart attack pills.
(via MeFi)