NTSB Factual Report

On July 23, 2004, at 1326 central daylight time, a Russian manufactured Yakovlev Yak 52 single-engine experimental airplane, N2331C, was substantialy damaged following a loss of control while performing low altitude aerobatics shortly after take off from the Claremore Regional Airport, near Claremore, Oklahoma. The commercial pilot/registered owner of the aircraft, was fatally injured. Visual meteorological conditions prevailed and no flight plan was filed for the aerobatic flight conducted under 14 Code of Federal Regulations Part 91.

According to a Federal Aviation Administration (FAA) safety inspector, the 1,700-hour pilot was performing at the Wings-over-Oklahoma Air Show. He departed Runway 17 (a 5,200-foot-long and 75 foot-wide asphalt runway), climbed to an altitude about 75 to 100-feet above the runway and rolled inverted. The pilot flew inverted about 1,500 feet down the length of the runway before the airplane settled onto the runway. The vertical stabilizer contacted the runway first followed by the roof of the airplane. A post-crash fire ensued around the cockpit area. The FAA inspector, who was working at the airshow at the time of the accident, examined the airplane and established control continuity for all flight controls. The wooden propeller was destroyed and the vertical stabilizer, rudder and cockpit area sustained structural damage. No pre-mishap anomalies were noted.

A witness, who was hired to professionally videotape the airshow, reported that he has seen the pilot's flight routine and practice sessions on numerous occasions. In a written statement he stated that "Initial takeoff roll and rotation I consider normal. Aircraft was slightly slower than usual. Pilot then rolled the aircraft inverted. Pitch angle was higher than normal and the typical gain in airspeed did not occur. The right wing of the airplane was low as the pitch angle increased, as in an inverted stall situation... Right wing low was correcting to level and full down elevator was applied during the maneuver to maintain an inverted climb." In addition, the witness said the flight control inputs looked to be correct during the maneuver and he did not observe anything unusual with the operation of the engine or the propeller.

Several other witnesses at the air show reported similar accounts of the mishap.

The weather at the airport at 1312 was reported as wind from 170 degrees at 3 knots, visibility 10 statute miles, clear skies, temperature 98 degrees Fahrenheit, dewpoint 69 degrees Fahrenheit, and a barometric pressure setting of 30.08 inches of Mercury.

NTSB Probable Cause

The pilot's failure to obtain adequate airspeed while executing a low altitude aerobatic maneuver, which resulted in an aerodynamic stall while inverted. A factor was the low altitude.