LAX08LA008 · Mooney M20F
Mooney M20F · Accident: total loss of engine power (mechanical failure) en route
From Gooding Municipal Airport (GNG) to North Las Vegas Airport (VGT)
Event
- NTSB case
- LAX08LA008
- 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
- 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
Mooney M20F
- Aircraft type
- Mooney M20
- 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
- N9612M
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Gooding Municipal Airport (GNG), Gooding, IDTo North Las Vegas Airport (VGT), Las Vegas, NV
- 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, ring › Fractured
- Fluid, oil › Exhaustion
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The pilot reported that before departing for the cross-country flight, he added 1 quart of oil to the engine, for a total of 7 quarts. About an 1 hour 30 minutes into the flight, he noticed a rise in oil temperature. The pilot opened the cowl flaps and increased the mixture. This resulted in a drop in exhaust gas temperature (EGT). The oil temperature continued to rise; however, the oil pressure indicated a low reading. The pilot declared an emergency, and prepared to land on a dirt road. The pilot reported that the engine was backfiring before it suddenly stopped (froze). Once the engine quit, the airplane rolled sharply to the right. The pilot was able to correct back to level flight and landed in a sagebrush field close to a road, which resulted in substantial damage to the wings. Examination of the wreckage revealed a hole in the crankcase above and below the number 4 cylinder. An attempt was made to manually rotate the crankshaft; however, only partial rotation was possible about 8 inches in either direction. The examination also revealed no oil on the outside of the airplane or on the cowl. Investigators drained the oil out of the oil sump for a total of 0.75 to 1.25 quarts of oil. Along with the oil, portions of crankcase, lifter, piston, and connecting rod material were in the oil sump. The oil filter was opened and contained metallic debris throughout the filament and in the can. All of the cylinders exhibited internal mechanical damage, as well as thermal damage to the number 4 connecting rod journal. The number 2 piston compression ring remained in its ring land, but had broken into several pieces. Extensive oil coking signatures were noted around the circumference of the number 2 piston at the ring land, which is consistent with oil burn.
Probable cause
Failure of the number 2 cylinder piston compression ring, which resulted in oil exhaustion and a catastrophic internal engine failure.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX08LA008
- Event ID
- 20071018X01613
- Case number
- LAX08LA008
- 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: 683b7e4f30a116bc4e0140bc6160cbe44c85df8b2ce04e5fdebb88e97ff0b295; retrieved 2026-09-22T03:21:34.695Z.