LAX00LA237 · Cessna 150M
Cessna 150M · Accident: total loss of engine power (mechanical failure) en route
From San Gabriel Valley Airport (EMT) to an unrecorded destination
Event
- NTSB case
- LAX00LA237
- 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
- N704QJ
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From San Gabriel Valley Airport (EMT)To 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
- Exhaust system, muffler › Eroded
- Ignition system, ignition lead › Burned
- Ignition system, magneto grounding lead (p-lead) › Melted
- Ignition system, magneto grounding lead (p-lead) › Shorted
- Other maintenance personnel › Maintenance, inspection, inadequate
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
During cruise, the engine lost power then nosed over during a forced landing in an open, dirt field. No mechanical anomalies were experienced with the engine sound or gages prior to the loss of engine power. About 10 minutes into the flight the engine began to run roughly. The CFI performed the emergency checklist and picked one of two open fields to make a forced landing. During the approach to the second field, a construction vehicle drove into their flight path. The CFI shortened the approach and landed in the first field. On the landing roll the nose wheel dug into the dirt and the airplane nosed over. The external examination of the engine revealed that the left muffler end cap had separated in an outward direction from the muffler about 350 degrees in circumference in a 45-degree angle. This allowed heat to be directed at the firewall. The P-leads located within the electrical harness were melted, which allowed the conductors to short within the wires.
Probable cause
The inadequate maintenance inspection by other maintenance personnel of the exhaust system that resulted in an eroded muffler that allowed hot gases to impinge on magneto wiring and resulted in loss of engine power. A factor was the soft terrain at the forced landing site.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX00LA237
- Event ID
- 20001212X21273
- Case number
- LAX00LA237
- 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: 1ade962f7bd762d65d525a2a38a26791c892330086116df2d11f6dff9f1f26b5; retrieved 2026-09-22T12:47:28.893Z.