What Happened
Chad had just completed a negative G maneuver followed by a four-point roll then a pitch up to vertical. At this point 22 seconds into the video, the engine hiccups and quits.
Trading altitude (2,500′) for airspeed, Chad dives in an attempt to aerodynamically re-start the engine. The blades turn a few times, but doesn’t restart the engine.
Twenty-one seconds after the engine quit, Chad is at 1,000’ and turning toward a gravel road. While setting himself up to land, he then uses the electric starter, which finally starts the engine.
Why It Happened
Like many aerobatic planes, the Pitts has an inverted fuel system. Chad’s Pitts has a 19 gallon fuel tank that feeds fuel into a flexible hose with a weight on the end called a flop tube. Gravity being a constant, both the fuel in the tank and the flop tube will always seek the “bottom” of the tank.