History of Flight
On June 8, 2020, at 0946 central daylight time, a Flight Design GMBH CTLS airplane, registration N257V, was destroyed in an accident near Beecher, Illinois. The pilot was fatally injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
No witnesses were present. Automatic dependent surveillance-broadcast (ADS-B) data indicated that the airplane accelerated to about 60 knots groundspeed and climbed to approximately 75 feet above ground level (agl). The groundspeed then decreased to about 50 knots while altitude increased to about 175 feet agl. At that point, the airplane was about 300 feet short of the departure end of the runway and began a descending left turn. The groundspeed remained about 50 knots during the turn. The accident site was in a harvested corn field about 0.4 mile northeast of the departure end of the runway and about 300 feet and 10° from the last recorded data point.
The field was flat with recently planted corn about 3 to 4 inches tall. The ground was firm, dry, and hard packed. Three linear marks at the accident site were consistent with the airplane’s tricycle landing gear. The center depression was deeper and longer, indicating a nose-low impact attitude. The nose landing gear and right main landing gear separated, and the airplane nosed over onto its back. The forward fuselage was crushed rearward and upward into the cabin. The wings were predominantly intact and still attached. The empennage separated from the fuselage at the leading edge of the vertical tail.
The airplane was equipped with a Dynon EMS-D120 engine monitoring system. Engine data showed engine start at 0937:40. Engine rpm remained below 3,000 rpm until 0944:55, when it increased to about 5,500 rpm, consistent with takeoff power. ADS-B data indicated that 2 seconds later, the airplane was 350 feet from the approach end of the runway at 35 knots groundspeed and a recorded altitude of 700 feet msl. Corrected for altimeter setting (30.03 in-hg), the altitude would have been about 800 feet msl. The field elevation at Bult Field Airport was 790 feet msl.
The Rotax 912ULS Operator’s Manual calls for a pre-takeoff ignition check at 4,000 engine rpm. Based on the engine monitor data, this ignition check was not performed, and engine rpm did not reach 4,000 rpm until takeoff power was applied.
The increase in engine speed at takeoff was accompanied by increases in manifold pressure and fuel flow. These parameters remained consistent with takeoff power until 0945:09, about 14 seconds after initial takeoff power application, when all three decreased sharply and engine speed dropped below 4,000 rpm. ADS-B data showed the airplane was about 1,300 feet from the approach end of the runway at a recorded altitude of 700 feet msl, indicating it was likely still on the runway. At that time, about 3,700 feet of runway remained ahead.
At 0945:10, ADS-B data showed the first altitude change since the beginning of the takeoff roll, indicating the airplane was airborne. It was about 1,500 feet from the approach end of the runway with about 3,500 feet of runway remaining.
Engine speed remained between 3,500 and 4,000 rpm until 0946:08, when rpm again decreased sharply and data ended.
Fuel pressure was steady at 40 psi until 0945:31, when it increased sharply to about 105 psi and remained until data end. The increase did not coincide with reductions in engine rpm.
Electrical system voltage was about 12.3 volts at flight start. It decreased throughout data, with the rate of decrease increasing about the time takeoff power was applied. Final recorded voltage was 9.3 volts. According to the aftermarket fuel injection manufacturer, the system operates down to about 7.5 volts. The Rotax 912 manual states the ignition system is powered from discrete coils in the engine stator, independent of accessory power. The effect of reduced voltage on other systems was not determined.
Personnel Information
Current pilot flight records were not available. The most recent records indicated the pilot had accumulated 995 hours of flight experience as of July 25, 2016, and had an instructor’s endorsement for a flight review conducted on April 18, 2018. No further flight records were available.
Wreckage and Impact Information
The airplane was powered by a Rotax 912 ULS engine modified with aftermarket electronic fuel injection and turbocharger systems.
A postaccident examination of the airframe and engine was conducted after removal from the site. The wings had been removed for transport and were predominantly intact. Impact damage was noted to the leading-edge tip of the left wing. Ailerons and flaps remained attached. The empennage and tail cone separated from the fuselage. Tail surfaces were intact, and rudder and elevator remained attached. The forward fuselage had extensive crushing damage. Control system continuity from cockpit controls to each surface was confirmed except for breaks associated with wing removal and impact damage. The fuel system showed no pre-impact anomalies.
The engine crankshaft rotated, confirming suction and compression on all cylinders, valve train continuity, and propeller reduction drive unit continuity. The top set of spark plugs were removed and exhibited normal burn signatures. The turbocharger rotated freely. Fuel lines and components showed no obstructions. Disassembly of the spring-loaded diaphragm fuel pressure regulator revealed no anomalies or debris. Field testing of the electronic ignition system was not possible.
The 3-blade controllable pitch composite propeller remained attached to the engine flange. One blade separated at the hub, a second about one foot from the hub, and a third about 1.5 feet from the hub. All three blade roots remained in the hub.
Medical and Pathological Information
The Will County Coroner’s Office performed an autopsy. The cause of death was multiple injuries due to an airplane mishap. The examination identified mild-moderate coronary artery disease with 50-60% stenosis of the proximal left anterior descending coronary artery without signs of previous ischemia. No other significant natural disease was identified.
Toxicology testing by NMS Labs identified caffeine and duloxetine in cardiac blood. Toxicology testing by the FAA Forensic Sciences Laboratory identified tamsulosin, amlodipine, atorvastatin, and benazepril in urine and cardiac blood. Duloxetine was also found in cardiac blood and urine.
Caffeine is a stimulant commonly found in coffee, tea, and sodas. Duloxetine is commonly marketed as Cymbalta and carries a warning that it may impair mental and/or physical ability required for potentially hazardous tasks.
Personal medical records revealed the pilot had a history of high blood pressure, high cholesterol, recurrent lumbar stenosis with sciatica, prediabetes, chronic fatigue, an enlarged prostate, and vitamin D deficiency. Medications at his last physician visit included aspirin, atorvastatin and omega-3-acid ethyl esters, benazepril, hydrochlorothiazide, amlodipine, finasteride, tamsulosin, and esomeprazole. These drugs are not generally considered impairing. Additionally, he was taking gabapentin, paroxetine, and ropinirole. Gabapentin had apparently been prescribed for sciatica. No diagnoses related to paroxetine or ropinirole were present, though a 2017 note indicated the pilot had sleep apnea without using a positive pressure device. No other sleep disorder treatment or evaluation was documented. The records did not identify when or why duloxetine was prescribed.