History of Flight
On September 2, 2015, at about 1403 eastern daylight time, an experimental amateur-built RV-8A, registration N393MC, crashed into a pond adjacent to Twin Lakes Airport (8A7) in Advance, North Carolina, shortly after takeoff. The flight, conducted under 14 Code of Federal Regulations Part 91 as a personal flight, had originated about three minutes earlier from 8A7. Visual meteorological conditions prevailed, and no flight plan was filed. The airplane was destroyed by impact forces, and the two occupants, both pilot-rated, sustained fatal injuries.
Before departure, neither occupant commented on any planned maneuver after takeoff. Witnesses observed a thorough preflight inspection performed by one or both occupants. After boarding, the front seat occupant passed a handheld tablet computer to the rear seat occupant and was heard to say, "you navigate," before the canopy was closed and the engine started. The airplane taxied to runway 27, where an engine run-up was performed, including checks of the magnetos and propeller; no discrepancies were reported.
The airplane became airborne at a normal location for that type and climbed to between 700 and 800 feet in a normal attitude. It remained in the traffic pattern for runway 27 and flew over the runway at an altitude between 200 and 300 feet above ground level at an estimated speed of 190 to 200 knots. Three witnesses on the ramp south of the runway near the approach end of runway 27 reported that, when the airplane was about halfway along the runway, it briefly pitched slightly nose down. One witness thought they might perform a roll or other maneuver, stating, "oh my god he is going to roll it," though he considered the altitude too low. The airplane then pitched slightly nose up and began a left roll about 1 to 1.5 seconds later, which developed into a barrel roll. As the airplane became inverted, the nose dropped to about 30 degrees nose low, but the roll continued.
The airplane then appeared to lower its tail and assume a nose-up attitude before impacting the water. Smoke was observed after impact. No smoke was seen trailing the aircraft during flight, and no components separated. The engine operated normally throughout the flight without any power setting change until impact. One witness reported not being in a position to see the flight controls during the final part of the flight but did not see the canopy open. The maneuver was described by one witness as not looking deliberate, stating: "I've seen snap rolls, barrel rolls, aileron rolls. I know what those maneuvers look like, and it was not one of those maneuvers."
Another witness saw the airplane descend below nearby buildings, heard the impact, drove to the site, and extinguished a small postcrash fire.
Personnel Information
The front seat occupant, aged 68, held a private pilot certificate with an airplane single engine land rating issued March 29, 2015. His application for that certificate listed 78.7 total flight hours; the checkride was in a Cessna 150L. He held a third-class medical certificate with a limitation to wear corrective lenses, issued July 8, 2014. No enforcement actions were on record.
The rear seat occupant, aged 71, held a commercial pilot certificate with airplane single engine land, multi-engine land, and instrument ratings. He had a third-class medical certificate with corrective lens limitation issued May 1, 2014, and reported 2,526 total civilian flight hours. Friends reported he was a former U.S. Air Force pilot, an instructor pilot in T-38s, and familiar with aerobatics.
Aircraft Information
The tandem-seat RV-8A was built in 2001, powered by a Lycoming IO-360-A1B6 engine with a Hartzell HC-C2YK-7766A2 constant-speed propeller. Both seats had flight controls for roll, pitch, and yaw, but the rear seat lacked engine controls. The airplane was co-owned by both occupants, purchased on September 8, 2014.
Maintenance records showed the last condition inspection was completed on September 25, 2014, at 152.32 total hours. On the accident day, brake maintenance was performed at 8A7; the log entry indicated 232 total flight hours.
Meteorological Information
A surface observation at Davidson County Airport (EXX) in Lexington, North Carolina, at 1355 reported calm wind, visibility 10 statute miles, clear skies, temperature 32°C, dew point 19°C, and altimeter 30.06 inHg. The accident site was about 10.9 nautical miles at 316° from EXX.
Wreckage and Impact Information
The airplane impacted a pond adjacent to the airport. The main wreckage, including the fuselage, empennage, and part of the main spar, was about 206 feet at 214° from the departure end of runway 27. Components were found in the pond, on land, and near the main wreckage. Debris was oriented on a magnetic heading of 320°. A fuel sheen was on the water; nearby vegetation showed browning consistent with fuel spill. All necessary components for flight remained attached or nearby.
The left wing had extensive impact damage; the full span was accounted for, and the lower wing skin showed fire damage. The flap remained attached, but the aileron with balance weight separated and was found nearby. The aileron bellcrank to aileron pushrod remained connected at the bellcrank but had a bent rod end. The aileron bellcrank to stick pushrod was bent and fractured. The bellcrank was deformed, and the main spar was buckled.
The right wing was fragmented; the full span was accounted for. The flap and aileron separated but were recovered. The aileron leading edge was crushed, and the balance weight was unrecovered. Pushrods were bent or fractured. Distortion was noted at the aileron bellcrank attach points. The flap was deformed and pulled from its hinge.
The empennage remained attached. The right horizontal stabilizer was bent in an inverted "V." The elevator pushrod was bent and fractured near the aft control stick. Rudder cables were fractured; remaining sections were connected to idler arms. The elevator trim tab and elevator were neutral.
The cockpit was fragmented; control assemblies separated. Aileron pushrods were fractured. The elevator rod end was bent and fractured. The control column was deformed. The rear seat control stick (P/N WD-812) separated from its base (P/N WD-412A); no securing hardware was found. The base had a single hole with deformation and scrape marks. The stick had two holes; full insertion matched the upper hole, with bulging and forward bending.
The flap actuator extended 2.25 inches, likely corresponding to flaps retracted. The airspeed indicator read 154 knots. Throttle, mixture, and propeller controls were full forward; the magneto switch was in the BOTH position. The tachometer read 0 rpm; oil pressure and temperature gauges were off-scale low.
The engine remained attached to the firewall. The two-blade propeller remained attached. Examination showed separation of some pushrods and tubes. Crankshaft, camshaft, and valve train continuity was confirmed for cylinders with pushrods in place. Compression and suction were confirmed for cylinders No. 2, 3, and 4. Cylinder No. 1 had compression escaping the exhaust valve due to an impact-bent valve. Fuel, ignition, and lubrication systems showed no preimpact failure.
One propeller blade had aft bending about 24 inches from the hub; the other had up and aft bending with leading edge impact damage. The spinner was impact-separated; the back plate remained attached.
Communications
A witness monitoring the airport's common traffic advisory frequency with a portable VHF transceiver reported hearing no distress calls from either occupant during the flight and did not hear their departure announced.
Medical and Pathological Information
Postmortem examinations performed by the Wake Forest Baptist Medical Center found multiple blunt force injuries in both occupants. No natural disease was noted. Both had fractures of the right ulna and radius.
Forensic toxicology by the FAA Bioaeronautical Sciences Research Laboratory showed testing for carbon monoxide and cyanide was not performed. No volatiles were detected. No tested drugs were found in the front seat occupant. In the rear seat occupant, unquantified Irbesartan was detected in the liver, and Rosuvastatin in the liver and muscle.
Tests and Research
Review of maintenance records showed that Van's Aircraft, Inc., Service Bulletin SB 07-2-6, a procedure to secure the rear control stick with a bolt and nut, was signed off as completed on September 25, 2014. Examination of the wreckage revealed the work was not properly performed due to the lack of a hole through both sides of the rear control stick base.
Pictures of the right aileron bellcrank to aileron pushrod damage and the left aileron bellcrank were submitted to the airframe designer's representative. The representative stated the as-found position of the left aileron bellcrank and pushrods was beyond normal travel for right aileron input and that, during normal full aileron deflection, the rivets on that pushrod would never contact the bellcrank or aircraft structure; the rivet damage was likely caused by overtravel during impact.
Probable Cause
Null