What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
On July 31, 2017 at approximately 0835 central daylight time the pilot performed a normal takeoff from Washington county airport (8WC) near Potosi, MO. This was the pilot's first flight in this airplane make and model. After climbing to approximately 100 150 feet above the airport elevation witnesses saw the aircraft begin a steeply banked turn to the right along with an abrupt steep nose-down change in pitch attitude. The airplane descended rapidly and struck the ground approximately 500 feet beyond the departure end of runway 02 in a pasture approximately 50 feet below the airport elevation.
The aircraft wreckage was inspected. Control cable continuity was established along with adequate fuel and engine compression. The required condition inspection was current at the time of the incident.
The pilot sustained injuries of a broken ankle requiring surgery, a back injury requiring surgery, abrasions and contusions.
The pilot suggested the possibility of a take-off and departure stall. The pilot stated that the airplane seemed to be wallowing just prior to making an uncommanded right turn along with an abrupt drop in pitch attitude. The pilot also states that in response he applied full opposite aileron and rudder with no response from the aircraft, further validating take-off and departure stall.
Multiple major modifications had been made to the aircraft including change to the size and shape of the aileron airfoil, addition of flaps, addition of flap controls, and modification to a tricycle gear of original design. None of these modifications had been adequately flight tested in accordance with the special airworthiness certificate and issued operating limitations.
As the FAA filed it
ON JULY 31, 2017 AT APPROXIMATELY 0835 CENTRAL DAYLIGHT TIME THE PILOT PERFORMED A NORMAL TAKEOFF FROM WASHINGTON COUNTY AIRPORT (8WC) NEAR POTOSI, MO. THIS WAS THE PILOT'S FIRST FLIGHT IN THIS AIRPLANE MAKE AND MODEL. AFTER CLIMBING TO APPROXIMATELY 100 150 FEET ABOVE THE AIRPORT ELEVATION WITNESSES SAW THE AIRCRAFT BEGIN A STEEPLY BANKED TURN TO THE RIGHT ALONG WITH AN ABRUPT STEEP NOSE-DOWN CHANGE IN PITCH ATTITUDE. THE AIRPLANE DESCENDED RAPIDLY AND STRUCK THE GROUND APPROXIMATELY 500 FEET BEYOND THE DEPARTURE END OF RUNWAY 02 IN A PASTURE APPROXIMATELY 50 FEET BELOW THE AIRPORT ELEVATION.
THE AIRCRAFT WRECKAGE WAS INSPECTED. CONTROL CABLE CONTINUITY WAS ESTABLISHED ALONG WITH ADEQUATE FUEL AND ENGINE COMPRESSION. THE REQUIRED CONDITION INSPECTION WAS CURRENT AT THE TIME OF THE INCIDENT.
THE PILOT SUSTAINED INJURIES OF A BROKEN ANKLE REQUIRING SURGERY, A BACK INJURY REQUIRING SURGERY, ABRASIONS AND CONTUSIONS.
THE PILOT SUGGESTED THE POSSIBILITY OF A TAKE-OFF AND DEPARTURE STALL. THE PILOT STATED THAT THE AIRPLANE SEEMED TO BE WALLOWING JUST PRIOR TO MAKING AN UNCOMMANDED RIGHT TURN ALONG WITH AN ABRUPT DROP IN PITCH ATTITUDE. THE PILOT ALSO STATES THAT IN RESPONSE HE APPLIED FULL OPPOSITE AILERON AND RUDDER WITH NO RESPONSE FROM THE AIRCRAFT, FURTHER VALIDATING TAKE-OFF AND DEPARTURE STALL.
MULTIPLE MAJOR MODIFICATIONS HAD BEEN MADE TO THE AIRCRAFT INCLUDING CHANGE TO THE SIZE AND SHAPE OF THE AILERON AIRFOIL, ADDITION OF FLAPS, ADDITION OF FLAP CONTROLS, AND MODIFICATION TO A TRICYCLE GEAR OF ORIGINAL DESIGN. NONE OF THESE MODIFICATIONS HAD BEEN ADEQUATELY FLIGHT TESTED IN ACCORDANCE WITH THE SPECIAL AIRWORTHINESS CERTIFICATE AND ISSUED OPERATING LIMITATIONS.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.