LAX06FA055 · Beech A23
Beech A23 · Accident: loss of engine power en route
From L12 · Redlands, CA to Mammoth Yosemite Airport (MMH)
Event
- NTSB case
- LAX06FA055
- 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
- 2 · 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
Beech A23
- Aircraft type
- Beechcraft 23
- 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
- N3590R
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From L12 · Redlands, CATo Mammoth Yosemite Airport (MMH), Mammoth Lakes, 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
- Loss of engine power
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Stall/spin
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Pilot in command › Airspeed, not maintained
- Reason for occurrence undetermined
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The airplane collided with flat desert terrain following an in-flight loss of control. A witness about 1 mile south of the accident site heard a rough running engine, and looked up to see what it was. As the airplane traveled overhead, he heard the engine "popping/backfiring," which lasted about 3 seconds, and then the engine quit. He then saw the airplane "dip" to the right, in a "tumbling motion." The witness indicated that it was like a somersault with the nose dropping and the tail coming over the top. He saw about 2 to 3 revolutions of the airplane, which lasted a total time of about 8 seconds, and then the airplane dropped below tree level and collided with the ground. The witness reported that it was somewhat cloudy in the area, but the airplane was below the clouds. When he arrived at the accident site to render aid, he reported there was no frost/ice on the wings, and that it was not cold enough for the formation of frost/ice. Witnesses at the departure airport reported that the engine sounded like the exhaust system was leaking very badly or that either the exhaust or muffler was loose. An engine test run could not be conducted due to displacement of the crankshaft caused by the nose-down impact. An engine teardown revealed no discrepancies in the engine core or in the accessories that would have precluded normal operation.
Probable cause
a loss of engine power for undetermined reasons, and, the failure of the pilot to maintain an adequate airspeed while maneuvering following the loss of power, which resulted in a stall/spin.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX06FA055
- Event ID
- 20051223X02007
- Case number
- LAX06FA055
- 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, coordinates. 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: 8e694fc7bad6d2a2fd64b87b6072149e438265eda88faa5894da16e1b92ba4e1; retrieved 2026-09-20T17:43:01.144Z.