History of Flight
On May 7, 2011, about 0855 central daylight time, a Woodward Ravin 500 experimental amateur-built airplane, N913RA, impacted forested terrain shortly after takeoff from Lone Star Executive Airport (CXO), Conroe, Texas. A postimpact fire ensued. Visual meteorological conditions prevailed. The personal flight was conducted under 14 CFR Part 91. The private pilot and student pilot-rated passenger were fatally injured.
According to the Air Traffic Control Tower transcript, at 0851:41 the pilot requested and received clearance for takeoff with a right turn on course. At 0853:48, the pilot reported "we have smoke in the cockpit." A female voice identified as the student pilot-rated passenger said "we're on fire." The tower controller cleared the airplane to land. At 0854:57, the pilot stated he was trying to reach the runway, with smoke in the cockpit but the airplane flying. At 0855:19, the passenger was heard saying "gear down," followed by "alright" from the pilot—the last transmission.
The tower controller observed the airplane make a 240-degree right turn, cross back over the departure runway, and enter a left downwind leg for runway 14 at an estimated 700-800 feet agl, appearing slow. After hearing "gear down," the controller saw the landing gear extend. The airplane then began a descending left turn towards runway 19, overshot the centerline, and turned sharply. It appeared to stall, descending left wing and nose low into trees from about 300 feet above the trees. No smoke was observed from the airplane.
The ground controller saw the airplane on downwind below 500 feet agl. He heard the passenger say "gear down" and saw the airplane abeam runway 19, slow, then enter an 80-degree bank turn. He noted no altitude to recover, describing it as a textbook base turn to final stall. He saw no smoke or flames.
A pilot-rated eyewitness near the crash site heard an engine "screaming" with varying RPM. He saw the airplane flying very slow at 300-500 feet agl. During a high bank turn back towards the airport, the nose and left wing dropped, and the airplane went out of sight, followed by impact and an explosion.
Personnel Information
The pilot, age 70, held a private pilot certificate with single-engine land rating. According to the airplane's insurer, he had over 3,400 total hours and about 150 hours in the make and model. He held a third-class medical certificate dated June 1, 2010, with the limitation "must wear corrective lenses."
The student pilot-rated passenger, age 52, held a student pilot certificate dated December 8, 2005, and a third-class medical certificate with the same limitation.
Aircraft Information
The airplane was a 2009 Harold W. Woodward Ravin 500, serial number 07050013, powered by a single Chevrolet LS1 fuel-injected reciprocating engine rated at 300 horsepower. It was an all-composite, low-wing, four-place design with retractable tricycle landing gear and retractable flaps, based on the Piper Comanche. The airworthiness certificate date was July 13, 2009. A conditional inspection was performed on July 14, 2010. No logbooks were found in the wreckage.
Meteorological Information
At 0853, the CXO METAR reported wind 180 degrees magnetic at 6 knots, visibility 10 statute miles, few clouds at 23,000 feet, temperature 68°F, dew point 63°F, altimeter 29.95 inHg.
Wreckage and Impact Information
The airplane came to rest upright about 1,600 feet from the approach end of runway 19 on an impact heading of 200 degrees magnetic. Broken trees preceded the crash site; some arrived with the airplane. Surrounding foliage was charred and consumed by fire. The main wreckage included all components; the structure was charred, melted, and consumed. The engine and propeller were charred and melted. Flight control continuity was confirmed.
Medical and Pathological Information
Autopsies performed on May 9 and 10, 2011, showed blunt injuries with associated thermal injuries and smoke inhalation. Toxicology on the pilot showed 2.24 µg/ml cyanide in blood (cavity), likely from ground fire and smoke inhalation due to absence of carbon monoxide. Toxicology on the passenger showed diphenhydramine in liver and kidney.
Tests and Research
The engine was examined on May 9, 2011. It was disassembled and inspected; valve train continuity was present, internal parts showed no preimpact distress. The propeller speed reduction unit had no anomalies. The electronic control unit (ECU) was thermally damaged and could not be tested. No abnormalities were found that would have prevented normal operation.
Additional Information
The airplane's owner stated that in the month before the accident, four of five flights had engine heating issues due to improper ventilation; each time he landed before coolant reached 210°F. The LS series engines are sensitive; at 4,000 rpm, temperature can climb to 230°F in seconds if cooling is inadequate. Above 230°F, the ECU engages safe mode controlling rpm to about 1,000 (later set to 3,000 by the owner's request). The owner said safe mode allowed the airplane to stay airborne for a safe landing but was not recommended. The owner believed the engine overheated due to insufficient cowling outflow and lack of radiator fans. The accident pilot had removed exhaust fans previously installed by the owner.