WPR12LA161 · Piper PA-28-181
Piper PA-28-181 · Accident: loss of engine power (total) en route
From Central Wyoming Regional Airport (KRIW) to Mitchell Municipal Airport (KMHE)
Event
- NTSB case
- WPR12LA161
- 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
Piper PA-28-181
- Aircraft type
- Piper PA-28
- 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
- N30997
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Central Wyoming Regional Airport (KRIW), Riverton, WYTo Mitchell Municipal Airport (KMHE), Mitchell, SD
- 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
- 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 (total)
- 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
During cruise flight, the engine sustained a reduction in oil pressure followed by a total loss of power. The student pilot then performed a forced landing into a field. Subsequent examination of the engine revealed that a piston pin plug had disintegrated, the fragments of which contaminated the oil passages and caused oil starvation and the subsequent engine seizure.
The engine's manufacturer issued a service instruction warning of such piston pin wear, recommending oil filter element inspection or spectrographic oil analysis at each oil change, not to exceed 50 hours of engine operation. The engine had undergone an oil change about 8 flight hours prior to the accident and the mechanic reported that the oil filter element appeared to be normal. Based on the relatively short period between the last oil filter inspection and the engine failure, the oil filter inspection should have revealed ample evidence of piston pin wear.
Probable cause
A total loss of engine power during cruise flight due to a failed piston pin plug, which resulted in engine oil contamination and subsequent oil starvation. Contributing to the loss of power was the failure of maintenance personnel to identify contaminants produced by the failing plug during the last oil filter inspection.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR12LA161
- Event ID
- 20120409X70107
- Case number
- WPR12LA161
- 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: local date, investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2012-04-08.
- API snapshot SHA-256: a5ca8c403b6724e3110db959cb5c018b8ad5422a30afd71b2aa4e5d90c34a0d9; retrieved 2026-09-15T17:42:17.279Z.