IAD97LA008 · Cessna 172
Cessna 172 · Accident: total loss of engine power (mechanical failure) en route
From CVG · Cincinnati, OH to K22 · Prestonsburg, KY
Event
- NTSB case
- IAD97LA008
- 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
Cessna 172
- Aircraft type
- Cessna 172
- 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
- N8299U
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From CVG · Cincinnati, OHTo K22 · Prestonsburg, KY
- 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
- Engine assembly, piston › Failure
- Engine assembly, ring › Failure
- Engine assembly, ring › Improper
- Maintenance, installation › Improper
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The flight was en route at 5500' MSL, when the pilot noted a loss of oil pressure followed by a loss of engine power. A forced landing was made in an open field, where the airplane collided with a ditch. Inspection of the airplane revealed the lower fuselage was covered with oil. Examination of the engine revealed evidence of oil starvation in the main bearings, connecting rod bearings, and journals of the crankshaft. All of the cylinders were steel-barreled, except the #4 cylinder, which was chrome plated. The #4 cylinder was heavily scored in the chrome barrel, and the #4 piston was scored completely around its skirt. The #4 piston exhibited burning on the lower crown, which eroded a hole to the piston interior below the third piston ring groove. The piston rings were stuck due to aluminum from the piston skirts extruding over them. Heat had expanded the piston skirts into contact with the cylinder walls, scoring them and transferring aluminum from the piston skirt. According to a report from the manufacturer, chrome cylinders must use plain steel rings per TCM service literature; however, the #4 cylinder was installed using rings for a steel barreled cylinder, which have chrome plating on the top compression ring. The manufacturer's report also noted that chrome ring on chrome cylinder bore will not work and could create scoring, metal transfer, and eventually severe blowby conditions. The engine had accumulated 1075 hours of flight time since the last overhaul.
Probable cause
improper maintenance with the installation of an improper oil ring on the number four piston, which led to failure of both the ring and pistion, oil starvation, and subsequent loss of engine power.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record IAD97LA008
- Event ID
- 20001208X06905
- Case number
- IAD97LA008
- 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: 328c7e0791a044f2ad843535c1df3050716be9cbf9a41d27b958e9dd53d33c5c; retrieved 2026-09-21T21:33:59.333Z.