CEN15LA238 · Piper PA-25-235
Piper PA-25-235 · Accident: loss of engine power (partial) while maneuvering
From Watonga Regional Airport (KJWG) to Watonga Regional Airport (KJWG)
Event
- NTSB case
- CEN15LA238
- 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-25-235
- Aircraft type
- Piper PA-25
- 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
- N7279Z
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Watonga Regional Airport (KJWG), Watonga, OKTo Watonga Regional Airport (KJWG), Watonga, OK
- Aircraft age
- About 50 years (built 1965)
- 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
- 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
- Organizational issues › Development
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The commercial pilot was conducting an agricultural application flight. During the flight, the airplane was unable to maintain altitude, and the pilot conducted an emergency landing on a dirt road. During the landing roll, the left wing struck a fence, crushing the leading edge. The pilot reported that the oil temperature was extremely high and that the engine was having a problem producing power.
A postaccident engine examination revealed metal particles in the engine oil, oil pump, and oil sump. The oil was black and smelled burnt. Coating was peeling off of the No. 5 cylinder wall. Energy dispersive spectroscopy analysis of the cylinder base metal produced a spectrum consistent with a steel alloy; the spectrum of the coating was consistent with a nickel-silicon carbide. It is likely that the coating was peeling either due to improper base metal preparation or contamination of the cylinder wall before it was coated, which resulted in poor bond strength between the coating and inner wall of the barrel. The metal particles from the peeled coating contaminated the engine oil and resulted in the partial loss of power.
Probable cause
Improper base metal preparation or contamination of the No. 5 cylinder wall before it was coated, which resulted in the coating peeling off of the cylinder wall and contaminating the engine oil and the subsequent partial loss of engine power.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN15LA238
- Event ID
- 20150520X45130
- Case number
- CEN15LA238
- 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. 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: b87136b1f4047bf3cda8d0d7075b5b4b6926c8dbb943cff75760f44b19fce0c1; retrieved 2026-09-16T02:20:12.189Z.