Probable cause
A loss of engine power that resulted from fuel contamination when it was treated with a 70% isopropyl alcohol solution (antiseptic) that contained water. Contributing to the accident were vague fuel treatment instructions provided by the operator.
NTSB analysis
The pilot reported that he was descending the airplane to begin patrolling a section of pipeline when, without warning, the engine began to surge between low and high power. He diverted towards the nearest airport and began troubleshooting the issue. When it became apparent that he could not maintain altitude and would not make the diversion airport, he performed an off-airport landing in a field. During the landing the airplane struck a 3- to 4-foot-tall berm, which resulted in substantial damage to the engine mount and fuselage.
During the post-accident investigation, a significant amount of water was found in the inline strainer to the engine. Follow-up interviews with the fixed base operator and pilot revealed that the pilot treated the airplane’s fuel with a 70% isopropyl alcohol (antiseptic) solution before the accident flight. The pilot was unaware that the antiseptic also contained purified water. It is likely that the airplane’s fuel became contaminated with water from the antiseptic which resulted in the loss of engine power.
Review of company documentation revealed vague instructions for treating the fuel with isopropyl alcohol. For example, the instructions stated to use one bottle per 25 gallons of fuel, but did not specify the size/volume of the bottle. Specific guidance for the accident airplane was found in the manufacturer’s service information letter. The letter stated it is permissible to use any high quality isopropyl alcohol, for example one meeting Federal Specification TT-I-735a. The letter stated the isopropyl alcohol may be blended with the fuel in a concentration not greater than 1% by volume.
Text from the NTSB. Open the NTSB docket for CEN25LA101 for the full record.
Event
- Date
- Feb 20, 2025
- Type
- Accident
- Place
- Farlinville, Kansas
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Cessna 177A
- N-number
- N30413
- Category
- Airplane
- Year built
- 1968
- Damage
- Substantial
- Operating rule
- Part 91 (general aviation)
- Purpose of flight
- Aerial observation
From the NTSB aviation accident database: N-registered aircraft, events since 2008, data through Oct 28, 2026. The file is published monthly, so the latest weeks are incomplete and recent records can change. The official source is the NTSB aviation investigation search. CheckAero is independent and not affiliated with the NTSB.