Mooney M20C accident near Visalia, California, September 21, 2010
On September 21, 2010 at about 4:40 pm local time, a Mooney M20C, registered N6090Q, was substantially damaged in an accident during takeoff near Visalia, California (Visalia Municipal airport). It was a personal flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A partial loss of engine power during takeoff, which resulted from the failure of the spark plug retention mechanism.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 21, 2010 · about 4:40 pm local time
- Place
- Visalia, California · Visalia Municipal · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Mooney M20C · all M20Cs on the register
- Registration
- N6090Q · no longer on the register · serial 3260
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot applied full engine power, took off, and climbed to about 300 feet above the runway. The engine suddenly lost partial power, and the pilot elected to return to the airport for a forced landing. The airplane’s altitude was insufficient to complete the turn, and the airplane impacted the ground adjacent to the departure runway, substantially damaging the right wing. An examination of the engine revealed that the retention mechanism for the bottom No. 3 spark plug failed and the spark plug had blown out of its cylinder. Its failure appeared related to excessive wear and the loosening over time of the Heli-Coil insert. According to the Federal Aviation Administration, evidence of the Heli-Coil’s loosening would not, necessarily, have been apparent to a mechanic during routine maintenance.
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
What happened, in order
- Powerplant sys/comp malf/fail during takeoff
- Loss of engine power (partial) during takeoff defining event
- Off-field or emergency landing during emergency descent
- Collision with terrain or object (not controlled flight into terrain) during landing (flare/touchdown)
The NTSB's findings
- cause Aircraft › Aircraft power plant › Ignition system › Spark plugs/igniters › Failure
- Personnel issues › Action/decision › (general) › (general) › Pilot
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 2,674 hours in all; 1,600 in this make and model; 10 in the last 90 days; 4 in the last 30 days; 2,294 as pilot in command
- Last flight review: August 28, 2009
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 6,718 hours
- Last inspection: annual inspection, April 30, 2010; 13 hours since
- Maximum gross weight: 2,575 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming O-360A1D (piston); 0 hours total
The flight
- Departed from: VIS Visalia Municipal CA at 4:39 pm
- Destination: VIS Visalia Municipal CA
- Flight plan: none
- Runway 30, 6,559 ft by 150 ft
Weather at the time
- Light: daylight
- Wind: from 150° at 3 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 66°F (19°C), dew point 55°F (13°C)
- Altimeter: 29.77 inHg
- Observation at 9:35 am from VIS
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight 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.