Varga Aircraft CORP. 2150A accident near Bowling Green, Ohio, June 1, 2017
On June 1, 2017 at about 3:59 pm local time, a 1977 Varga Aircraft CORP. 2150A, registered N4635V, was substantially damaged in an accident during enroute near Bowling Green, Ohio (Conklin airport). It was a personal flight under general aviation rules (Part 91). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's loss of control due to impairment from carbon monoxide poisoning. Contributing to the accident was the corrosion of the heat exchanger and the failure of maintenance personnel to adequately inspect and repair or replace the exchanger during the most recent annual inspection.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 1, 2017 · about 3:59 pm local time
- Place
- Bowling Green, Ohio · Conklin · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Varga Aircraft CORP. 2150A A, built 1977 · all 2150As on the register
- Registration
- N4635V · no longer on the register · serial VAC-91-78
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The private pilot was performing a visual flight rules cross-country flight after purchasing the airplane. After flying for about 1 hr 20 minutes, the airplane suddenly entered a spiraling descent from cruise flight. Witnesses observed the airplane flying erratically at low altitude before it impacted an open field; they stated that the engine was running until impact. Toxicological testing of specimens taken from the pilot found 55% carbon monoxide saturation of blood. At carbon monoxide levels above 40%, people typically experience incapacitating symptoms such as severe confusion, agitation, seizures, loss of consciousness, and death. Examination of the airplane's heat exchanger showed that the outside casing had either previously been repaired or had been originally constructed of metals with different properties. About one-half of the casing was discolored and exhibited varying signs of corrosion (the other half did not). Small holes were found where corrosion had occurred in the casing material. The holes from the corrosion provided a means for carbon monoxide to enter the cockpit from the exhaust system. Federal guidelines for annual aircraft inspections require an inspection of the exhaust systems for cracks, defects, and improper attachment during each 100-hour or annual aircraft inspection. Maintenance logbooks indicated that the airplane's most recent annual inspection was completed less than 1 month before the accident. The available maintenance logbooks did not contain any record of repairs or replacement of the heat exchanger. However, the condition of the heat exchanger is indicative of an insufficient annual inspection that did not detect and correct the corroded heat exchanger. It is likely that impairment caused by acute carbon monoxide poisoning led to the pilot's loss of airplane control. The corrosion in the heat exchanger allowed carbon monoxide to enter the cabin.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Aircraft maintenance event during prior to flight
- Loss of control in flight during enroute
- Collision with terrain or object (not controlled flight into terrain) during enroute
- Medical event during enroute
- Powerplant sys/comp malf/fail during enroute defining event
The NTSB's findings
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- cause Personnel issues › Physical › Impairment/incapacitation › Carbon monoxide › Pilot
- factor Aircraft › Aircraft power plant › Engine exhaust › (general) › Fatigue/wear/corrosion
- factor Personnel issues › Task performance › Maintenance › Scheduled/routine maintenance › Maintenance personnel
Pilot
- Certificate: private
- Ratings: single-engine land; instrument: airplane
- Flight time: 793 hours in all
- Medical certificate: BasicMed
- Seat: frt
- Injury: fatal
The aircraft
- Airframe total time: 2,410 hours
- Last inspection: annual inspection, May 5, 2017; 3 hours since
- Maximum gross weight: 4,006 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O-320-A2C (piston); 2,410 hours total
The flight
- Departed from: 3G6 Sebring OH at 3:34 pm
- Destination: OI92 Bowling Green OH
- Flight plan: none
Weather at the time
- Light: daylight
- Sky: clear
- Temperature: 57°F (14°C), dew point 48°F (9°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number CEN17FA207.