NTSB Factual Report

HISTORY OF FLIGHT

On July 9, 2011, about 1030 central daylight time, an amateur-built Bowie Sonerai II airplane, N113RB, impacted into a farm field near Dudley, Missouri. The pilot was fatally injured. The airplane sustained substantial damage to its left wing and fuselage. The aircraft was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which was not on a flight plan. The flight originated from the Dexter Municipal Airport, Dexter, Missouri, at an unconfirmed time.

The airplane was discovered in the field and reported to the Missouri State Highway Patrol. There were no eyewitnesses to the accident.

PERSONNEL INFORMATION

The pilot held a private pilot certificate with airplane single engine land and instrument airplane ratings. A review of the pilot’s most recent flight logbook (2005 to present) revealed that he had accumulated 2,243 total flight hours and had logged 53 hours in the accident airplane. His most recent flight review, as required by 14 CFR 61.56, was dated June 29, 2011. The pilot’s Airman Medical Certificate was issued on December 22, 2010 and specified that the pilot have glasses available for near vision when exercising the privileges of his pilot certificate.

AIRCRAFT INFORMATION

The airplane was an amateur-built Sonerai II, serial number 395. It was a single engine, mid-wing monoplane with a tailwheel landing gear arrangement. It was equipped to seat 2 occupants in a tandem. The fuselage and tail surfaces were constructed of welded steel tubing with a fabric covering and the wings were constructed of aluminum. The airplane was powered by a converted four cylinder Volkswagen engine.

METEOROLOGICAL INFORMATION

At 0953, the weather conditions recorded at the Poplar Bluff Municipal Airport (POF), about 12 miles west of the accident site were: Wind from 100 degrees at 3 knots; 6 statute miles visibility; clear skies; temperature 28 degrees Celsius; dew point 23 degrees Celsius; altimeter setting 29.93 inches of mercury.

WRECKAGE AND IMPACT INFORMATION

The airplane impacted a level farm field about one mile southwest of Dudley, Missouri. The airplane came to rest upright, facing southeast and there was an impact point about 25 feet northwest of the wreckage. The left wing leading edge was bent in an upward direction and buckling of the main spar upper cap strips adjacent to the wing spar inboard attachment point was evident. The right wing showed little damage. The inboard portions of the main wing spars as well as the spar carry-through structure had been cut to facilitate extrication of the pilot. The fuselage was crushed rearward and upward with the damage extending from the firewall to the aft seat location within the cabin. The aft fuselage and the tail surfaces remained intact with minimal damage. The ailerons, elevator, and rudder remained attached to the airframe and all hinges were intact. Control system continuity was verified from the tail surface to the cockpit controls. The aileron bellcranks were still attached to the control stick assembly. The rear wing spar carry through structure was buckled forward and the actuation pins on the aileron root ribs were dislodged from their respective control bellcranks. The damage to the airframe was consistent with a left wing low, nose down, attitude at impact.

The engine was removed from the firewall and continuity of the rotating components was verified by rotation of the crankshaft. The engine had two spark plugs per cylinder and the upper set of spark plugs was removed. No anomalies were evident with regard to the spark plugs. Suction and compression was evident on all four cylinders during crankshaft rotation. The engine had two separate ignition systems, one magneto, and one electronic ignition system. The magneto was removed and spark was evident from all four spark plug leads during hand rotation of the input shaft. The electronic system consisted of a dual pickup assembly mounted in the distributor mounting hole and two motorcycle style ignition coils mounted on the firewall of the airplane. The pickup cover was removed and rotation of the rotor was evident during crankshaft rotation. The two electronic ignition pickups were intact and secure. No visible anomalies were evident with regard to the electronic ignition system. The propeller was of wood construction covered with carbon fiber. One blade was broken and the other was intact.

The fuel system consisted of one fuel tank, which fed fuel via gravity feed through a fuel shutoff valve and gascolator, to a slide type carburetor. The carburetor used a tapered needle to vary fuel flow based on throttle position and was not equipped with a float bowl. The gascolator was about 3/4 full of fluid that was consistent in color with 100LL aviation gasoline. The fuel tank contained no fuel at the accident site, however; the operation of the carburetor was such that when the engine was not running the fuel shutoff valve would be closed to prevent the fuel in the tank from continuing to flow through the carburetor and into the intake system. No fuel odor was present in the soil beneath the engine or carburetor.

The postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy of the pilot was performed at the Mineral Area Regional Medical Center Morgue, Farmington, Missouri, on July 11, 2011. According to the autopsy report, the cause of death in this case was closed head injury as a result of small plane crash.

The toxicology results revealed no carbon monoxide or cyanide in the blood and no ethanol in the vitreous. However, quinine was detected in urine and tetrahydrocannabinol (THC/marijuana) was detected in blood (0.0035 ug/ml) and its primary metabolite, tetrahydrocannabinol carboxylic acid (THC-COOH/marijuana) was detected in blood (0.0016 ug/ml), liver, lung (0.0241 ug/ml), and urine (0.023 ug/ml).

Quinine, an antimalarial, is the principal ingredient in tonic water, is available over the counter, and may also be prescribed to treat or prevent leg cramps. At usual doses, it has no significant performance effects.

Marijuana is a psychoactive drug with therapeutic levels as low as 0.001 ug/ml. According to the National Highway Traffic Safety Administration’s (NHTSA) Drugs and Human Performance Fact Sheets, “It is difficult to establish a relationship between a person's marijuana blood or plasma concentration and performance impairing effects. Concentrations of parent drug and metabolite are very dependent on pattern of use as well as dose. THC concentrations typically peak during the act of smoking, while peak 11-OH THC concentrations occur approximately 9 to 23 minutes after the start of smoking. Concentrations of both analytes decline rapidly and are often less than 0.005 ug/mL at 3 hours. Significant THC concentrations (0.007 to 0.018 ug/mL) are noted following even a single puff or hit of a marijuana cigarette. Peak plasma THC concentrations ranged from 0.046 to 0.188 ug/mL in 6 subjects after they smoked 8.8 mg THC over 10 minutes. Chronic users can have mean plasma levels of THC-COOH of 0.045 ug/mL, 12 hours after use; corresponding THC levels are, however, less than 0.001 ug/mL.” “Most behavioral and physiological effects return to baseline levels within 3 to 5 hours after drug use, although some investigators have demonstrated residual effects in specific behaviors up to 24 hours, such as complex divided attention tasks. Psychomotor impairment can persist after the perceived high has dissipated. In long term users, even after periods of abstinence, selective attention (ability to filter out irrelevant information) has been shown to be adversely affected with increasing duration of use, and speed of information processing has been shown to be impaired with increasing frequency of use.”

ADDITIONAL INFORMATION

A portable global positioning system receiver was located within the airplane’s wreckage. The unit was retrieved and the recorded flight data downloaded. The review revealed that there was no data from the accident flight.

NTSB Probable Cause

Fuel starvation due to the pilot’s improper fuel management and his decision to conduct the flight while under the influence of marijuana.