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LAX88FA297 · Mooney M20J

23 Aug 1988 · Inyokern, CA, United States

Flightworks Aviation Mooney M20J · Accident: in flight encounter with weather en route

From Van Nuys Airport (VNY) to Mammoth Yosemite Airport (MMH)

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Event

NTSB case
LAX88FA297
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
1 · 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

Mooney M20J

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
N5769Y
Onboard fatalities
Unknown
Route
From Van Nuys Airport (VNY), Van Nuys, CATo Mammoth Yosemite Airport (MMH), MAMMOTH, 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
In flight encounter with weather
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 › Aircraft handling, not maintained
  • Pilot in command › Flight into known adverse weather, attempted

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

WEATHER REPORTS FROM A NEARBY AIRPORT AND WITNESS OBSERVATIONS INDICATE THAT A LEVEL 4 THUNDERSTORMS WAS NEAR THE ACCIDENT SITE AS THE ACFT APPROACHED. THE PLT DID NOT OBTAIN A PREFLT WX BRIEFING FOR THIS NIGHT VFR CROSS COUNTRY. THE WX INFORMATION AVAILABLE AT THE TIME HE DEPARTED CLEARLY NOTED THE THUNDERSTORM WITH HEAVY RAIN AND LIGHTENING PRESENT ON HIS ROUTE. RADAR DATA SHOWED THE ACFT TRACKING ALONG A HIGHWAY WITH THE MODE C REPORTING ERRATIC ALTITUDE JUMPS. THE RADAR DATA SHOWED THE ACFT TURN RIGHT TIGHTLY AND DESCEND AT A RAPID RATE. EVIDENCE AT THE SITE SHOWED THE ACFT CONTACTED THE GROUND IN A 60 DEGREE RIGHT BANK TURN WITH THE NOSE DOWN AT ABOUT 40 DEGREES AND AT A HIGH RATE OF SPEED. THE PLT WAS NOT CURRENT FOR NIGHT FLT.

Probable cause

PILOTS INFLIGHT LOSS OF CONTROL AFTER ENCOUNTERING A LEVEL FOUR THUNDERSTORM ON A NIGHT VFR CROSS COUNTRY. CONTRIBUTING TO THE ACCIDENT WAS THE PILOT'S FAILURE TO OBTAIN A PREFLIGHT WEATHER BRIEFING.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record LAX88FA297
Event ID
20001213X26590
Case number
LAX88FA297
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: local date, investigation status. Values present in the bulk record are kept.
  • The date is the local date; the NTSB stores the UTC date 1988-08-24.
  • API snapshot SHA-256: f2b59f57060cceb9a8426866a9e480e0aca25cbcc7d1e7a94df27306242e3c30; retrieved 2026-09-21T03:35:40.468Z.