N34WSStephenson Wilbur R STOL CH 701 · 2004

On October 24, 2014, about 1900 eastern daylight time, an experimental amateur-built Stephenson STOL CH 701 airplane, N34WS, struck powerlines and impacted terrain near Mount Vernon, Indiana. A ground fire subsequently occurred. The pilot, who was the sole occupant, was fatally injured. The airplane sustained substantial damage. The airplane was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as personal flight. Visual flight rules conditions prevailed for the flight, which did not operate on a flight plan. The local flight originated from a private airstrip at time unknown.

A witness, who was working farmland just north of the accident site, reported that he was traveling eastbound on his tractor when the airplane flew from behind and to the right of his position. The airplane was about 30 feet above ground level and about 50 feet to the farmer's right. When the airplane passed him, it pitched up and turned right heading southbound. He observed the airplane flying "right into the powerlines." The power lines arced and the airplane caught on fire. The power lines held the airplane aloft. The witness called 911 and drove to the accident site. The airplane was on the ground and the fire engulfed the airplane when he arrived at the site.

The 69 year-old pilot held a Federal Aviation Administration (FAA) private pilot certificate with a single-engine land airplane rating. The pilot's most recent FAA airman medical certificate was a third class medical certificate, dated October 3, 2012. The certificate contained limitations to wear lenses for distant vision and possess glasses for near vision. The pilot reported on the application for that medical certificate that she had accumulated 987 hours of total flight time and 39 hours of flight time in the six months prior to the exam.

N34WS was an experimental amateur-built, two-seat, high wing, fixed landing gear Stephenson STOL CH 701 airplane with serial number 7-5218. It was issued a special airworthiness certificate on March 28, 2005. According to airworthiness records, the airplane was powered by a Rotax 912 ULS engine and equipped with a Warp Drive propeller.

At 1855, the recorded weather at the Henderson City-County Airport, near Henderson, Kentucky, was: Wind calm; visibility 10 statute miles; sky condition broken clouds at 4,700 feet; temperature and dew point missing; altimeter 30.05 inches of mercury.

N34WS was an experimental amateur-built, two-seat, high wing, fixed landing gear Stephenson STOL CH 701 airplane with serial number 7-5218. It was issued a special airworthiness certificate on March 28, 2005. According to airworthiness records, the airplane was powered by a Rotax 912 ULS engine and equipped with a Warp Drive propeller.

An FAA inspector responded to the accident site, obtained a witness statement, examined the wreckage, and took photographs of the site. The wreckage was found about 15 yards from a local road. Power lines that paralleled the road were separated. The examination of the wreckage site revealed that the wreckage was discolored, charred, and melted. Flight control continuity was observed and no pre-impact anomalies were observed that would have precluded operation of the airplane.

FAA regulation 91.17 Alcohol or drugs, in part, stated:

(a) No person may act or attempt to act as a crewmember of a civil aircraft -

(1) Within 8 hours after the consumption of any alcoholic beverage;

(2) While under the influence of alcohol;

… or

(4) While having an alcohol concentration of 0.04 or greater in a blood

or breath specimen. Alcohol concentration means grams of alcohol

per deciliter of blood or grams of alcohol per 210 liters of breath.

FAA regulation 91.119 Minimum safe altitudes: General, in part, stated:

Except when necessary for takeoff or landing, no person may operate

an aircraft below the following altitudes:

...

(c) Over other than congested areas. An altitude of 500 feet above the

surface, except over open water or sparsely populated areas. In those

cases, the aircraft may not be operated closer than 500 feet to any person,

vessel, vehicle, or structure.

A Posey County Sheriff's Officer interviewed the witness. During the interview, the witness, in part, stated that he saw the accident airplane flying two or three days prior to the accident. The airplane "swooped" low and close to the combine where he was working. The airplane then climbed and flew away. He could not identify who had flown the airplane but confirmed it was the accident airplane.

An autopsy was performed on the pilot and toxicological samples were taken by the Posey County Coroner's Office. The autopsy ascribed the ground fire as the pilot's cause of death.

The FAA Civil Aerospace Medical Institute (CAMI) prepared a Final Forensic Toxicology Accident Report following testing of the pilots toxicological samples. The report indicated:

148 (mg/dL, mg/hg) Ethanol detected in Vitreous

118 (mg/dL, mg/hg) Ethanol detected in Brain

121 (mg/dL, mg/hg) Ethanol detected in Blood (Heart)

...

0.164 (ug/ml, ug/g) Diazepam detected in Blood (Heart)

0.219 (ug/ml, ug/g) Diazepam detected in Liver

0.346 (ug/ml, ug/g) Diphenhydramine detected in Blood (Heart)

Diphenhydramine detected in Liver

Fluoxetine detected in Blood (Heart)

Fluoxetine detected in Liver

0.07 (ug/ml, ug/g) Lorazepam detected in Liver

0.734 (ug/ml, ug/g) Nordiazepam detected in Liver

Nordiazepam detected in Blood (Heart)

Norfluoxetine detected in Blood (Heart)

Norfluoxetine detected in Liver

Oxazepam detected in Liver

Oxazepam NOT detected in Blood (Heart)

The CAMI website, in part, stated:

Diazepam: A frequently prescribed antianxiety agent, muscle relaxant,

and anticonvulsant. This drug is metabolized into nordiazepam,

temazepam, and oxazepam, which are also active. [It is commonly

marketed with the name Valium.]

Diphenhydramine: Is a common over the counter antihistamine used in

the treatment of the common cold and hay fever. [It is available over the

counter under the trade names Benadryl and Unisom.]

Ethanol: This is primarily a social drug with a powerful central nervous

system depressant. After absorption, ethanol is uniformly distributed

throughout all tissues and body fluids. The distribution pattern

parallels the water content and blood supply of each organ.

Postmortem production of ethanol also takes place due to putrefaction

processes, but vitreous humor and urine do not suffer from such

production to any significant extent in relation to blood. Vitreous

humor would normally have about 12 [percent] more ethanol than blood

if the system is in the post absorptive state, and urine would normally

have about 25 [percent] more ethanol than blood. The average rate of

elimination of ethanol from blood is 18 mg/dL (15-20 mg/dL) per hour.

Fluoxetine: An atypical antidepressant (SSRI) with the selective

serotonin reuptake inhibiting action. It is biotransformed to the active

metabolite, norfluoxetine. [It is commonly marketed with the name

Prozac.]

Lorazepam: Is a tranquilizer used in the treatment of

anxiety disorders. [It is commonly marketed with the name Ativan.]

Nordiazepam: A metabolite of several different benzodiazepines which

are used as a treatment for anxiety.

Norfluoxetine: A metabolite of fluoxetine which is used as a treatment

for depression.

Oxazepam: Is a tranquilizer used in the treatment of anxiety disorders

and a metabolite of Nordiazepam and Temazepam.

The National Transportation Safety Board Chief Medical Officer reviewed the CAMI findings, FAA

documents, and autopsy. According to these items, the pilot reported no chronic medical conditions and

no medications to the FAA. The pilot was issued a third class medical certificate limited by a requirement to wear corrective lenses for distant vision and possess glasses for near vision.

CAMI's toxicology testing identified ethanol at 0.148 gm/dl in vitreous, 0.118 gm/dl in brain, and 0.121 gm/dl in heart blood. After ingestion, at low doses, it impairs judgment, psychomotor functioning, and vigilance; at higher doses it can cause coma and death. The effects of ethanol on aviators are generally well understood; it significantly impairs pilots' performance, even at very low levels as reviewed and described in research papers articles published on alcohol and aviation.

Ethanol may also be produced in body tissues after death by microbial action; when this occurs, levels from various tissues tend to vary widely. The CAMI report indicated that there was no putrefaction in the toxicological sample sent for testing.

The medications found in the pilot's toxicological samples were on the FAA's Guide for Aviation Medical Examiners "Do Not Issue" list for aviation medical examiners; pilots who report "regular or intermittent use of any drug or substance classified under the Controlled Substances Act (Schedules I - V)" should not be issued a medical certificate. Fluoxetine is one of four antidepressants that may be allowed for pilot use by the FAA but special issuance medication certification is required and will only be issued after a favorable review of the effectiveness of the treatment by a Human Intervention Motivation Study aviation medical examiner. FIREA witness reported that the airplane caught on fire when he saw it hit the power lines. The airplane subsequently came to rest on the ground and an image of the wreckage was consistent with an isolated fire that charred and discolored grass around the perimeter of the airplane.