History of Flight
On October 24, 2014, about 1900 eastern daylight time, an experimental amateur-built Stephenson STOL CH 701 airplane, registration N34WS, struck powerlines and impacted terrain near Mount Vernon, Indiana. A ground fire ensued. The pilot, the sole occupant, was fatally injured. The airplane sustained substantial damage. The aircraft was registered to and operated by the pilot under 14 CFR Part 91 as a personal flight. Visual flight rules conditions prevailed; no flight plan was filed. The local flight originated from a private airstrip at an unknown time.
A witness working farmland north of the accident site reported that he was traveling eastbound on a tractor when the airplane approached from behind and to his right, about 30 feet above ground level and 50 feet to his right. As it passed, the airplane pitched up and turned right, heading southbound. He observed the airplane fly directly into the powerlines, which arced, and the aircraft caught fire. The powerlines briefly suspended the airplane. The witness called 911 and drove to the site, finding the airplane on the ground engulfed in flames.
Personnel Information
The 69-year-old pilot held an FAA private pilot certificate with a single-engine land airplane rating. Her most recent FAA third-class medical certificate was issued October 3, 2012, with limitations to wear corrective lenses for distant vision and possess glasses for near vision. On that application, she reported 987 total flight hours and 39 hours in the previous six months.
Aircraft Information
N34WS was an experimental amateur-built, two-seat, high-wing, fixed-landing-gear Stephenson STOL CH 701, serial number 7-5218. It received a special airworthiness certificate on March 28, 2005. The aircraft was powered by a Rotax 912 ULS engine and equipped with a Warp Drive propeller.
Meteorological Information
At 1855, weather at Henderson City-County Airport near Henderson, Kentucky, recorded calm wind, visibility 10 statute miles, sky condition broken clouds at 4,700 feet, and altimeter 30.05 inches of mercury. Temperature and dew point were missing.
Wreckage and Impact Information
An FAA inspector examined the wreckage, obtained a witness statement, and photographed the site. The wreckage was located about 15 yards from a local road. Powerlines parallel to the road were severed. The wreckage was discolored, charred, and melted. Flight control continuity was confirmed, and no pre-impact anomalies were observed that would have prevented operation.
Medical and Pathological Information
An autopsy was performed, and the Posey County Coroner's Office attributed the cause of death to the ground fire. Toxicological samples were taken. The FAA Civil Aerospace Medical Institute (CAMI) prepared a Final Forensic Toxicology Accident Report, which detected ethanol in vitreous (148 mg/dL), brain (118 mg/dL), and heart blood (121 mg/dL). Additionally, diazepam (0.164 µg/mL in heart blood), diphenhydramine (0.346 µg/mL in heart blood), fluoxetine, lorazepam, nordiazepam, norfluoxetine, and oxazepam were detected in various tissues. The CAMI website described these substances as antianxiety agents, antihistamines, antidepressants, and their metabolites. The FAA regulation 91.17 prohibits crewmembers from acting with a blood alcohol concentration of 0.04 or greater or within 8 hours of consuming alcohol. The National Transportation Safety Board Chief Medical Officer reviewed the findings; the pilot had reported no chronic medical conditions or medications on her FAA medical application. Ethanol at low doses impairs judgment and psychomotor function. CAMI noted no putrefaction in the samples, suggesting the ethanol was not postmortem production. The detected medications appear on the FAA's "Do Not Issue" list for medical certification, though fluoxetine may be permitted under special issuance.
Fire
A witness reported that the airplane caught fire upon striking the powerlines. The aircraft came to rest on the ground, and fire charred and discolored the grass around the perimeter.
Probable Cause
No probable cause was stated in the source.