Mooney M20K accident near Flagstaff, Arizona, October 3, 1990
On October 3, 1990 at about 7:46 pm local time, a Mooney M20K, registered N231AX, was destroyed in an accident near Flagstaff, Arizona. It was a business flight under general aviation rules (Part 91). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE PILOT'S DECISION TO OPERATE THE AIRCRAFT WITH A KNOWN DISCREPANCY; INADEQUATE MAINTENANCE PROCEDURES; AND THE PILOT'S INFLIGHT LOSS OF CONTROL DUE TO SMOKE AND FUMES IN THE COCKPIT.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 3, 1990 · about 7:46 pm local time
- Place
- Flagstaff, Arizona · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Mooney M20K · all M20Ks on the register
- Registration
- N231AX · no longer on the register · serial 25-0114
- Damage
- Destroyed
- Flight
- Business flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE PILOT HAD RETURNED FROM AN EARLIER DEPARTURE BECAUSE HE HAD SMOKE INSIDE THE AIRPLANE, AND REQUESTED THE ASSISTANCE OF A MECHANIC. UNABLE TO OBTAIN THIS ASSISTANCE, HE BORROWED A PAIR OF PLIERS FROM THE FBO. AFTER INSPECTING THE AIRPLANE HIMSELF, HE RETURNED THE PLIERS AND COMMENTED SOMETHING ABOUT THE EGT PROBE TO THE LINE PERSON ON DUTY. SOON AFTER THE SECOND DEPARTURE, THE AIRPLANE WAS SEEN RETURNING TOWARDS THE AIRPORT TRAILING SMOKE AND POSSIBLY FIRE. THE AIRPLANE ROLLED INVERTED AND DESCENDED INTO TREES. THE AIRPORT MANAGER RESPONDING TO THE ACCIDENT SCENE LOCATED THE EXHAUST TAILPIPE. THE FRACTURED TURBO CLAMP WAS LOCATED AT THE WRECKAGE. METALLURGICAL ANALYSIS REVEALED THAT CRACKING OCCURRED AS A RESULT OF INTERGRANULAR CORROSION. ON 9/26/90 THE TURBOCHARGER WAS REMOVED, REPAIRED AND REINSTALLED.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land; instrument: airplane
- Flight time: 4,800 hours in all; 100 in the last 90 days
- Medical certificate: Class 2 (expired)
- Seat: unk
The aircraft
- Last inspection: inspection type not recorded; 0 hours since
- Maximum gross weight: 2,900 lb
- Seats: 4
- Landing gear: retractable
- Engine: Continental TSIO-360-GB (piston); 0 hours total
The flight
- Destination: UNK Unknown
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 310° at 8 knots
- Visibility: 20 statute miles
- Sky: clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
- Observation at 7:55 pm from FLG, 1 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.