LAX91LA276 · Cessna 150M
Pegasas Flight Center Cessna 150M · Accident: total loss of engine power (mechanical failure) en route
From an unrecorded airport to Fullerton Municipal Airport (FUL)
Event
- NTSB case
- LAX91LA276
- 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 150M
- 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
- N3674V
- Operator
- Pegasas Flight Center
- Onboard fatalities
- Unknown
- Route
- From not recordedTo Fullerton Municipal Airport (FUL), Fullerton, CA
- 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, rocker arm/tappet › Fractured
- Engine assembly, valve, exhaust › Seized
- Pilot in command › Operation with known deficiencies in equipment, intentional
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
WHILE CRUISING NEAR A BEACH THE AIRPLANE'S ENGINE LOST ALL POWER. THE PILOT MADE A FORCED LANDING OFF SHORE. UPON TOUCHING DOWN IN SHALLOW WATER THE AIRPLANE NOSED OVER. THE EXAMINATION OF THE ENGINE REVEALED THAT ITS NO.1 CYLINDER'S EXHAUST VALVE HAD PROBABLY BECOME STUCK IN ITS GUIDE, & ULTIMATELY THE ROCKER ARM BROKE. FURTHER INVESTIGATION REVEALED THAT TWO DAYS BEFORE THE ACCIDENT THE PILOT HAD EXPERIENCED A POWER LOSS & WHEN THE ENGINE WAS EXAMINED THE SAME STUCK VALVE WAS FOUND. THE MECHANIC WHO FREED UP THE VALVE HAD CAUTIONED THE PILOT THAT, ALTHOUGH HE WAS SUCCESSFUL IN FREEING UP THE VALVE, THE ENGINE WAS IN NEED OF AN OVERHAUL & THE VALVE COULD BECOME STUCK, AT ANY TIME, DURING FUTURE FLIGHTS. THE ENGINE HAD BEEN OPERATED FOR ABOUT 1857 HOURS SINCE ITS LAST MAJOR OVERHAUL.
Probable cause
THE SEIZURE OF THE NO. 1 CYLINDER'S EXHAUST VALVE IN ITS GUIDE AND THE RELATED FRACTURING OF THE ROCKER ARM; AND THE PILOT'S OPERATION OF THE AIRCRAFT WITH KNOWN DEFICIENCIES.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX91LA276
- Event ID
- 20001212X17326
- Case number
- LAX91LA276
- 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: ab493ced53fb523ab59891d9a14d23518fa8c19dc557103b3581048da5f26100; retrieved 2026-09-21T23:33:16.512Z.