Piper PA-32R-301T accident near Groveland, California, February 20, 2010
On February 20, 2010 at about 3:17 am local time, a Piper PA-32R-301T, registered N4175A, was substantially damaged in an accident during enroute (descent) near Groveland, California (Pine Mountain Lake Airport). It was a personal flight under general aviation rules (Part 91). 2 people were killed. The weather was instrument conditions (cloud, fog or low visibility).
The NTSB's probable cause their words, unchanged
The pilot's continued flight into night instrument meteorological conditions during the landing approach, which resulted in an in-flight loss of aircraft control due to spatial disorientation.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 20, 2010 · about 3:17 am local time
- Place
- Groveland, California · Pine Mountain Lake Airport · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- instrument conditions (cloud, fog or low visibility)
- Aircraft
- Piper PA-32R-301T · all PA-32R-301Ts on the register
- Registration
- N4175A · registry record · serial 3257193
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The instrument-rated pilot departed at night without obtaining a weather briefing or filing an instrument flight plan. Radar track data revealed no deviations of heading or altitude for the en route segment, indicative of consistent autopilot usage. For a portion of the flight, the pilot was in communication with air traffic control (ATC) and was receiving flight following. As he approached the airport he reported to ATC that the airport was not in sight and that he would return if it was covered in a fog layer. The radar data indicated that the airplane continued to overfly the runway and begin a series of rapid altitude and heading changes. Multiple witnesses reported hearing an airplane flying with high engine speeds in the vicinity of the airport subsequent to its collision with the ground. The wreckage path, instrument indications, and damage to surrounding trees were indicative of a high-speed, 80-degree-right-bank, and 45-degree-nose-down collision with terrain. The pilot, having flown only two instrument approaches in the preceding 6 months, was not current to fly an instrument approach. He had limited experience landing at the accident airport at night and had never performed an instrument approach into the airport in actual instrument meteorological conditions (IMC). The airplane was equipped with an autopilot and instruments suitable for flight in IMC. Impact damage and postaccident fire prevented a determination of the operational status of these systems. Examination of the remaining wreckage revealed no evidence of premishap or mechanical malfunctions of the engine and airframe. An hour prior to the accident, another pilot reported performing a missed approach at the arrival airport due to limited visibility, followed by a diversion to an alternate airport. Witnesses and en route weather reporting facilities reported low clouds, fog, and precipitation in the vicinity of the airport. The weather conditions and operation at night were conducive to the onset of pilot spatial disorientation as indicated by the airplane's multiple rapid descents, ascents, and heading changes after the airplane passed over the airport.
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
- VFR encounter with IMC during enroute (descent) defining event
- Loss of control in flight during approach (VFR go-around)
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
The NTSB's findings
- Environmental issues › Conditions/weather/phenomena › Ceiling/visibility/precip › Below VFR minima › Effect on personnel
- cause Personnel issues › Action/decision › Info processing/decision › Decision making/judgment › Pilot
- cause Personnel issues › Psychological › Perception/orientation/illusio › Spatial disorientation › Pilot
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Directional control › Not attained/maintained
- Environmental issues › Conditions/weather/phenomena › Light condition › Dark › Effect on personnel
Pilot
- Certificate: private
- Ratings: single-engine land; instrument: airplane
- Flight time: 1,083 hours in all; 443 in this make and model; 20 in the last 90 days; 0 in the last 30 days; 1,083 as pilot in command
- Last flight review: March 20, 2009
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: left
- Injury: fatal
The aircraft
- Airframe total time: 1,310 hours
- Last inspection: annual inspection, May 9, 2009; 90 hours since
- Maximum gross weight: 3,600 lb
- Seats: 7
- Landing gear: retractable
- Engine: Lycoming TIO-540 (piston); 0 hours total
The flight
- Departed from: SQL San Carlos CA at 2:25 am
- Destination: E45 Groveland CA
- Flight plan: none
- Runway 09, 3,624 ft by 50 ft
Weather at the time
- Light: night
- Visibility: 1 statute miles
- Sky: overcast at 300 ft
- Temperature: 48°F (9°C), dew point 46°F (8°C)
- Altimeter: 29.82 inHg
- Observation at 2:45 am from 022, 16 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 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.
Other NTSB records under N4175A the same tail number, which may have belonged to a different aircraft at the time
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.