Until the advent of the Pitts Special, aerobatics was a horizontal affair, even in the hairy-chested, fuel-sucking, 450-HP Boeings and Wacos. Practitioners pirouetted under the stern God of Energy Management—gravity and drag meant vertical maneuvers were brief events.
A small, clean biplane taking advantage of progressively more powerful, and lighter, opposed engines being developed took akro through the roof.