CEN14LA412 · Enstrom F 28F
Paul Peterson Aviation Enstrom F 28F · Accident: loss of engine power (partial) while maneuvering
From Tomah, WI (private airstrip) to Tomah, WI (private airstrip)
Event
- NTSB case
- CEN14LA412
- 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
- 0 · 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
Enstrom F 28F
- Aircraft type
- Enstrom F-28
- Category
- Helicopter
- 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
- N213BL
- Operator
- Paul Peterson Aviation
- Onboard fatalities
- Unknown
- Route
- From Tomah, WI (private airstrip)To Tomah, WI (private airstrip)
- Aircraft age
- About 19 years (built 1995)
- 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 137: Agricultural
- 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
- Loss of engine power (partial)
- 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 power plant
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The pilot felt a vibration in the cyclic control and he stated that the engine was running irregularly as he neared the intended application field on the agricultural application flight. He immediately elected to execute a precautionary landing to a cornfield; the corn crop was about 10 feet tall at the time. During the landing, the landing skids collapsed, and the tailboom was severed by a main rotor blade. A postaccident examination of the engine revealed that the No. 4 cylinder did not exhibit compression during crankshaft rotation. Further examination of the No. 4 cylinder revealed that the intake valve did not seat properly; a gap of about 0.015 inch existed when the valve should have been fully seated. Linear scoring was observed on the valve stem, and debris consistent with valve guide material was also recovered upon removal of the valve. No other anomalies with respect to the engine were observed. The engine had accumulated about 831 hours since overhaul. The helicopter maintenance records did not contain a record of any unresolved maintenance issues.
Probable cause
A loss of engine power due to the malfunction of the No. 4 cylinder intake valve.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN14LA412
- Event ID
- 20140807X92309
- Case number
- CEN14LA412
- 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, coordinates. 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: 9ab27866e51529fef5c7e336d8d7455af8382d0081cdb7fc27814430cc9d2849; retrieved 2026-09-16T01:37:00.736Z.