SEA95LA190 · Mooney M20K
Mooney M20K · Accident: total loss of engine power (mechanical failure) en route
From 3S2 · AURORA STATE, OR to Bismarck Municipal Airport (BIS)
Event
- NTSB case
- SEA95LA190
- 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
- 0
- 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
Mooney M20K
- Aircraft type
- Mooney M20
- 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
- N1154L
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From 3S2 · AURORA STATE, ORTo Bismarck Municipal Airport (BIS), Bismarck, ND
- Aircraft age
- Not recorded
- 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
- En route · cruise
- First occurrenceThe 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
- Total loss of engine power (mechanical failure)
- 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
- Lubricating system, oil pressure pump › Disabled
- Lubricating system, oil pressure pump › Foreign object
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot reported that while cruising 28 miles north of Roundup, Montana, the engine surged momentarily, then returned to normal RPM. He then noted that the oil pressure had dropped to zero, and turned toward the Roundup airport for an emergency landing. He reported that the engine failed 3 minutes later and that he could not make the airport. He then made a forced landing in a field 9 miles north of Roundup. The airplane went through a barbed-wire fence during landing. A postaccident engine examination revealed a metal chip between the oil inlet screen and the oil pump inlet. The inlet screen was split open along the solder seam and the oil pump inlet was gouged. A scanning electron microscope examination of the chip revealed that the chip was copper-plated steel characteristic of material used in the engine gears and camshaft. Teledyne Continental also reported that the oil screen appeared to have been subjected to an axial compressive load at an undetermined time.
Probable cause
an engine failure due to foreign object ingestion into the oil pump. A ruptured oil inlet screen contributed to the accident.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA95LA190
- Event ID
- 20001207X04388
- Case number
- SEA95LA190
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
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: 42c3532e9a2972905789ac845562fc1f59133d8b691dd6d146bb114dc6473a7a; retrieved 2026-09-22T23:22:32.389Z.