Amateur-built GLASAIR III SH-3R accident near Lake Mathews, California, October 23, 2010
On October 23, 2010 at about 8:32 pm local time, a amateur-built GLASAIR III SH-3R, registered N2XZ, was substantially damaged in an accident during maneuvering near Lake Mathews, California. It was a personal flight under general aviation rules (Part 91). 2 people were killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot’s failure to maintain clearance from terrain while maneuvering at low altitude beneath a cloud layer.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 23, 2010 · about 8:32 pm local time
- Place
- Lake Mathews, California · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built GLASAIR III SH-3R
- Registration
- N2XZ · no longer on the register · serial 3155
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
Review of recorded radar data found a flight track that was consistent with the airplane's high performance capabilities, with its departure point, and ultimately with the accident site. The radar data indicated that a few seconds after the airplane passed over the runway's end, it turned toward the southeast, accelerated to about 190 knots ground speed, and proceeded directly toward the accident site area around a lake. No mode C altitude data was transmitted by the transponder. Upon arrival over the lake, the airplane made two counterclockwise oval-shaped 360-degree turns, with the steepest bank performed as the airplane approached the lake's eastern shoreline. The last radar return was located over the lake's eastern shoreline and within 250 feet of the wreckage location. Based on weather reports from an airport 7 miles northeast of the accident site, an overcast or broken cloud layer at 2,500 feet above ground level likely existed over the accident site. Based on an examination of the crater and airplane wreckage, the airplane impacted the ground at a high airspeed while descending in a slight bank and with the airplane's longitudinal axis pitched downward (nose low) between 55 and 70 degrees. The impact signatures could be consistent with the pilot attempting either a loop or split "S"-type maneuver at an altitude insufficient to recover. There were no witness reports and postaccident examination of the wreckage did not reveal any evidence of a preimpact mechanical malfunction or failure of any airframe or engine component or system.
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
- Low altitude operation/event during maneuvering defining event
- Collision with terrain or object (not controlled flight into terrain) during maneuvering
The NTSB's findings
- Environmental issues › Conditions/weather/phenomena › Ceiling/visibility/precip › Low ceiling › Contributed to outcome
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Angle of attack › Not attained/maintained
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
Pilot
- Certificate: airline transport pilot, flight instructor
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 11,305 hours in all; 20 in this make and model
- Medical certificate: Class 1 (with waivers/limitations)
- Seat: unk
- Injury: fatal
Pilot
- Certificate: airline transport pilot, flight instructor, flight engineer
- Ratings: multi-engine land; single-engine land; single-engine sea; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 11,500 hours in all
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: unk
- Injury: fatal
The aircraft
- Airframe total time: 600 hours
- Last inspection: annual inspection, May 1, 2010; 20 hours since
- Maximum gross weight: 2,500 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming IO-540-K1A5 (piston); 0 hours total
The flight
- Departed from: AJO Corona Muni. CA at 8:24 pm
- Destination: AJO Corona Muni. CA
- Flight plan: none
- A second pilot was aboard
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: overcast at 2,900 ft
- Temperature: 66°F (19°C), dew point 54°F (12°C)
- Altimeter: 30.06 inHg
- Observation at 7:53 pm from RAL, 6 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 2 |
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.