ATL94LA165 · Cessna 150J
Eagle Wings Aviation Cessna 150J · Accident: total loss of engine power (mechanical failure) en route
Event
- NTSB case
- ATL94LA165
- 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 150J
- Aircraft type
- Cessna 150
- 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
- N50446
- Operator
- Eagle Wings Aviation
- Onboard fatalities
- Unknown
- Route
- From not recordedTo not recorded
- 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, valve, exhaust › Seized
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
DURING CRUISE FLIGHT OVER MOUNTAINOUS TREE COVERED TERRAIN, THE ENGINE LOST POWER. IT CONTINUED TO DECREASE TO IDLE AS THE PILOT GLIDED THE ACFT TO A SMALL CLEARING. THE AIRPLANE WAS LANDED UPSLOPE, ROLLED OVER A HILL, AND COULD NOT BE STOPPED BEFORE COLLIDING WITH TREES. THERE WAS NO BRAKING FRICTION BECAUSE OF WET GRASS. DURING A POST ACCIDENT INSPECTION, A STUCK EXHAUST VALVE WAS FOUND IN THE NUMBER 2 CYLINDER. THE HEAD OF THE VALVE STEM WAS DISCOLORED AND HAD THE APPEARANCE OF A VARNISH-LIKE COATING. MEASUREMENTS OF THE VALVE STEM AND GUIDE SHOWED THAT THE STEM WAS 0.0075 MICROMETERS LARGER THAN THE GUIDE. FOURTEEN MONTHS EARLIER A VALVE HAD STUCK IN THE NUMBER 4 CYLINDER. SINCE THE AVAILABILITY OF THE AUTO FUEL STC, THE ENGINE HAD BEEN OPERATED ABOUT 25%-50% OF ITS HOURS WITH AUTO FUEL. RECENT CYLINDER COMPRESSION CHECKS HAD BEEN WITHIN LIMITS.
Probable cause
A seized cylinder exhaust valve because of deposits on the valve and an oversized valve stem. The lack of suitable terrain for a forced landing was a factor.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ATL94LA165
- Event ID
- 20001206X01945
- Case number
- ATL94LA165
- 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: 3c8c155210d531ff96264507ac3e2f07a5f40d7b1f0dbb7dfc2fe8ce1057084b; retrieved 2026-09-21T22:30:57.898Z.