CEN15LA026 · Stephenson STOL CH 701
Stephenson STOL CH 701 · Accident: low altitude operation/event while maneuvering
From Mount Vernon, IN to Mount Vernon, IN
Event
- NTSB case
- CEN15LA026
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 1 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Stephenson STOL CH 701
- Aircraft type
- Stephenson STOL CH 701
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N34WS
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Mount Vernon, INTo Mount Vernon, IN
- Aircraft age
- About 10 years (built 2004)
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Maneuvering · low-altitude flying
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Low altitude operation/event
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Wire
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Aircraft › Aircraft oper/perf/capability
- Environmental issues › Physical environment
- Personnel issues › Action/decision
- Personnel issues › Physical
- Personnel issues › Psychological
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The private pilot was conducting a local personal flight. A witness who was working in a field reported observing the pilot flying the airplane about 30 ft above ground level and 50 ft to his right. The airplane banked right and then impacted power lines. The power lines arced when the airplane contacted them, and the airplane subsequently caught on fire and was fully engulfed in fire when the witness arrived at the accident site. An examination of the airplane did not reveal any preimpact anomalies that would have precluded normal operation.
Toxicological testing detected ethanol at 0.148 grams per deciliter (gm/dl) in the vitreous (Federal Aviation Administration regulations only allow 0.040 gm/dl of ethanol) and relatively similar levels of ethanol in the pilot's brain and blood specimens, which indicates that most of the ethanol was likely due to ingestion rather than postmortem production; therefore, she was likely intoxicated and impaired by ethanol at the time of the accident.
In addition, the pilot had significant levels of diazepam and diphenhydramine in her heart blood. The detected levels for both drugs were likely therapeutic; however, in regular use, diazepam causes sedation and diphenhydramine causes marked sedation. Therefore, the pilot was likely impaired by both diazepam and diphenhydramine at the time of the accident.
In summary, the pilot's judgment and psychomotor functions were likely significantly impaired by a combination of ethanol intoxication and the effects of both diazepam and diphenhydramine at the time of the accident. The combined effects of these impairing substances likely led to the pilot's improper decision to conduct low-level flight, affected her ability to safely operate the airplane, and resulted in her failure to maintain clearance from power lines.
Probable cause
The pilot’s impairment due to the ingestion of alcohol and sedating medications, which led to her improper decision to conduct low-level flight, affected her ability to safety operate the airplane, and resulted in her failure to maintain clearance from power lines.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN15LA026
- Event ID
- 20141025X00646
- Case number
- CEN15LA026
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: eeefc73aefb27d4dc4203ee986341ba68c52da8461ed45a5d1fd6412b0fa0a98; retrieved 2026-09-14T17:27:55.203Z.