Accident Overview
On June 6, 2016, at 1759 eastern daylight time, an experimental, amateur-built Duo Deuce, registration N808DD, was substantially damaged when it collided with terrain shortly after takeoff from Stafford Regional Airport (RMN) in Stafford, Virginia. The commercial pilot, who was also the owner and builder of the aircraft, sustained serious injuries. Visual meteorological conditions prevailed, and no flight plan was filed for the initial test flight, which was conducted under 14 Code of Federal Regulations Part 91.
Accident Sequence
During the initial climb after takeoff, the pilot reported a sudden loss of power from both engines. She identified an open area for a forced landing. Upon touchdown, the airplane nosed over and came to rest inverted. In a subsequent interview, the pilot stated that the right engine stopped producing power. She also reported that during the takeoff roll, the airplane reached flying speed, the nose lifted, and she advanced the throttles to 2,700 rpm. As the airplane became airborne, the left wing rose while the right wing dropped. She added left rudder and left aileron, but realized the airplane was consuming too much runway and insufficient runway remained to land. She turned right to avoid an interstate highway beyond the departure end. The pilot stated, "I stalled I guess, I hit the ground pretty hard." In a later media interview, the pilot recalled that the purpose of the taxi onto the runway was a high-speed taxi and that the takeoff was inadvertent. She described an engine failure followed by an aerodynamic stall.
Witness Observations
Several witnesses provided statements. One witness, well-acquainted with the pilot, described the flight as a test flight and first flight for the airplane. Witnesses reported that the takeoff and climb were slow, with the airplane wobbling and wings rocking. One witness estimated the airplane climbed to about 300 feet above the runway before slowly descending.
Video Analysis
Review of videos from two airport security cameras and an on-board video recorded on the pilot's cellphone showed a shallow takeoff and initial climb. Almost immediately after takeoff, the airplane's track diverged from the runway centerline to the right, over the grass apron. The climb stopped at approximately treetop height, the wings rocked, and the airplane pitched up as it descended until ground contact. The instrument panel was not visible, but both propellers appeared to turn at constant and consistent speeds throughout the takeoff roll and flight until ground contact.
Aircraft Information
The two-seat, twin-engine, low-wing airplane was equipped with two Lycoming IO-320-B1A engines. It was initially registered in 2013 and issued an airworthiness certificate on March 19, 2016. The pilot modified a Van's Aircraft RV-8 single-engine kit, configuring it with two wing-mounted engines instead of the original nose-mounted single-engine design. Maintenance records revealed that the engines were previously owned and installed on an airplane involved in an accident on February 19, 2008, during which each engine experienced a propeller strike. The records did not indicate that a mandatory sudden-stoppage inspection was performed after that event.
Pilot Information
According to FAA records, the pilot held a commercial pilot certificate with ratings for airplane single and multiengine land and sea, and a flight instructor certificate with ratings for airplane single and multiengine. She was issued an FAA second-class medical certificate on October 29, 2015, and reported 6,420 total hours of flight experience.
Post-Accident Examination
The airplane was recovered to Shannon Regional Airport in Fredericksburg, Virginia, where representatives from the NTSB and Lycoming Engines examined it. The right engine, still mounted in its nacelle and attached to the airframe, was test-run. After removing the damaged constant-speed propeller and installing a fixed-pitch propeller, the engine started and ran smoothly and continuously. Throttle changes resulted in smooth power transitions, and engine oil pressure and fuel flow indications were consistent. With full throttle, approximately 2,200 rpm was observed, and the engine ran roughly, consistent with a lean fuel/air mixture. Fuel flow indicated approximately 19 gallons per hour (gph), while typical requirements for that power setting are 8.5 to 10 gph. The abnormal fuel flow was consistent with air entering the fuel system upstream of the engine on the airframe side.