Cessna 150 accident near Madison, South Dakota, August 14, 2018
On August 14, 2018 at about 1:00 pm local time, a 1975 Cessna 150, registered N6341K, was substantially damaged in an accident during maneuvering near Madison, South Dakota (Madison Muni airport). It was an instructional flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A stuck No. 3 cylinder exhaust valve, which resulted in failure of the associated rocker arm, a partial loss of engine power, and the subsequent forced landing into tall vegetation.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 14, 2018 · about 1:00 pm local time
- Place
- Madison, South Dakota · Madison Muni · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 150 M, built 1975 · all 150s on the register
- Registration
- N6341K · registry record · serial 15077654
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The student pilot reported that he was flying north of the departure airport when the airplane's engine began running roughly. He attempted to return to the airport but was unable to reach the airport and landed in a cornfield. The airplane nosed over in the 7-ft-tall corn and sustained substantial damage to both wings. Examination of the airplane revealed that the engine's No. 3 cylinder exhaust valve was stuck in its valve guide, and the No. 3 exhaust valve rocker arm was fractured. A maintenance record entry indicated that the Nos. 1, 3, and 4 cylinders had experienced valves sticking and had been sent back to the overhaul vendor for service. The cylinders were reinstalled 3 days before the accident. Based on the available evidence, the partial loss of engine power was likely due to the No. 3 cylinder exhaust valve becoming stuck, which resulted in a secondary overload failure of the associated rocker arm and a substantial reduction in engine power output.
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
- Loss of engine power (partial) during maneuvering defining event
- Collision with terrain or object (not controlled flight into terrain) during landing
- Nose over/nose down during landing
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Malfunction
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Failure
- cause Environmental issues › Physical environment › Terrain › High elevation › Contributed to outcome
Pilot
- Certificate: student
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Last inspection: annual inspection, July 10, 2018; 7 hours since
- Maximum gross weight: 1,600 lb
- Seats: 2
- Landing gear: fixed
- Engine: Continental O-200A (piston); 0 hours total
The flight
- Departed from: MDS Madison SD at 12:10 pm
- Destination: MDS Madison SD
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 150° at 3 knots
- Visibility: 10 statute miles
- Sky: a few clouds at 8,000 ft
- Temperature: 70°F (21°C), dew point 70°F (21°C)
- Altimeter: 29.95 inHg
- Observation at 12:55 pm from MDS
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
2 documents, released by the NTSB on February 20, 2019. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 2 | Engine Maintenance Records | PDF, 3 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.