Background
The accident occurred during the Experimental Aircraft Association’s AirVenture 2010 fly-in convention. Due to the high density of aircraft operations, the Federal Aviation Administration had implemented special air traffic control procedures to accommodate traffic demand and maximize runway capacity. Arriving aircraft were issued landing instructions by a tower controller on a specified frequency, while departing aircraft were handled by a separate team of controllers operating on a different frequency from a mobile operations unit near the runway.
Sequence of Events
Air traffic control data showed that the accident airplane established contact with the tower controller and entered a left traffic pattern for runway 18R. As the airplane turned from downwind to base leg, the controller handling departures cleared a Piper Cub for an immediate takeoff and angled departure—a procedure used by slower aircraft to clear the runway immediately after liftoff by turning across the runway edge. The accident pilot was not monitoring the departure frequency and thus did not hear transmissions indicating the Piper Cub would offset to the left after liftoff.
On base leg, the accident pilot became concerned that his descent path would conflict with the Piper Cub on takeoff roll. He overshot the runway centerline during his turn from base to final, and when he completed the turn, his airplane was offset to the right of the runway. Perceiving a conflict with the Piper Cub ahead and to the left, he decided not to land and initiated a go-around. He increased engine power slightly—estimated at about one-third of the throttle travel—but not to takeoff power, as he looked for additional traffic to avoid. The stall warning stick-shaker and stick-pusher systems activated almost simultaneously as the right wing stalled. The airplane subsequently collided with terrain in a nose-down, right-wing-low attitude.
A postaccident review of air traffic control communications, amateur video, controller and witness statements, and position data indicated that the Piper Cub was already airborne, had turned left, and was clear of runway 18R when the accident airplane turned from base to final.
Postaccident Examination
The postaccident examination did not reveal any preimpact mechanical malfunctions or failures that would have precluded normal operation of the airplane. The airplane flight manual states that during a go-around, the pilot should first advance engine thrust to takeoff power and then establish Vref (reference landing approach speed).
Probable Cause
The pilot's decision not to select takeoff power during the go-around, as stipulated by the airplane flight manual, which resulted in an aerodynamic stall at a low altitude.