Accident Details
On November 5, 2016, about 0756 mountain daylight time, an experimental, amateur-built Stamper RV-10 airplane (registration N924WY) impacted terrain following a loss of control shortly after takeoff from Dubois Municipal Airport (DUB) in Dubois, Wyoming. The private pilot was fatally injured, and the airplane was destroyed. The flight was a local test flight conducted under 14 CFR Part 91 in day visual meteorological conditions; no flight plan was filed.
Witness Account
A witness observed the airplane take off from runway 28. Upon liftoff, the right gull-wing cabin door rotated open. The witness saw the pilot reach for the fully open door with his right hand and heard a momentary reduction of engine power. The airplane descended momentarily before the witness heard an increase in engine power and saw the airplane level off about 35 feet above ground level over the runway. As the pilot continued to reach for the open door, the airplane overflew the remaining runway. The witness then saw the left wing and nose drop suddenly, describing the event as an aerodynamic stall. The airplane descended into terrain, and a large explosion occurred on impact.
Pilot Information
The 44-year-old pilot held a private pilot certificate with ratings for airplane single-engine land, airplane single-engine sea, and instrument airplane. His most recent FAA second-class medical certificate was issued on September 17, 2015, with no limitations. According to his logbook, the pilot had accumulated 1,482.1 total flight hours as of October 10, 2016. He had logged 1.8 hours in the accident airplane. Insurance records indicated the pilot reported 1,500 total hours, with 40 hours in Van's RV-6 and 4 hours in Van's RV-10 aircraft, and 2 hours in the accident airplane.
Aircraft Information
The airplane, serial number 40146, was a single-engine, low-wing monoplane of conventional aluminum construction. It was powered by an experimental 260-horsepower Aero Sport Power IO-540-D4A5 engine and a three-blade Whirl Wind Aviation 375RV composite propeller. The four-seat airplane had fixed tricycle landing gear and wing flaps, with a maximum takeoff weight of 2,700 pounds. The pilot assembled the airplane from a kit, and it received a special airworthiness certificate on April 23, 2016. The airplane likely had accumulated 10 to 12 hours since certification and had not completed Phase I flight test requirements. Fuel capacity was 60 gallons, and the tanks were topped off before the flight.
The airplane was equipped with two upward-opening gull-wing cabin doors made of composite material. Each door had a rack and pinion latch mechanism with two latch pins that extended into pin sockets in the doorjamb. An aftermarket center latch system with a rotating semicircular cam provided an additional latch point. The doors lacked the additional safety latch mechanism provided by the kit manufacturer. A latch indicator system using magnetic reed switches and magnets in the latch pins was installed.
Meteorological Information
At 0755, the Dubois Municipal Airport automated surface observing system reported wind from 270 degrees at 6 knots, visibility 10 miles, clear sky, temperature 0°C, dew point -8°C, and an altimeter setting of 30.29 inches of mercury.
Wreckage and Impact Information
The initial point of impact was in an open field about 1,675 feet past the runway 28 departure threshold and 183 feet left of the extended runway centerline. The debris path was 67 feet long on a heading of 210°. A ground impact crater containing propeller fragments was located about 44 feet from the initial impact. The main wreckage, including the fuselage, wings, and empennage, was destroyed by postimpact fire. The right cabin door was found in a ravine about 600 feet northeast of the main wreckage, having separated from its hinges. The door showed no evidence of striking the airplane after separation. The door latch handle was observed about 110° from the fully latched position, and the latch pins were extended about 1/8 inch. A functional test of the latch mechanism revealed no anomalies. When the handle was in the latched position, the pins extended about 1 1/4 inches, and the center latch curved portion faced down.
Engine examination revealed continuity, compression on cylinders 1, 2, 3, and 5, and thermal damage to valve springs on cylinders 4 and 6. The magneto was thermally damaged, and the electronic ignition module was not recovered. Upper spark plugs showed normal wear. The propeller hub remained attached; two blades were destroyed, and the remaining blade had thermal damage.
Medical and Pathological Information
An autopsy attributed the pilot's cause of death to extensive thermal injuries and blunt force injuries sustained during the accident. Toxicological tests were negative for carbon monoxide, ethanol, and all tested drugs.
Additional Information
A search of the NTSB accident database revealed a previous accident involving a Van's RV-10 (NTSB ID NYC07LA237) where the right cabin door separated in flight. The pilot in that event declared an emergency and landed safely.