Amateur-built ZODIAC accident near Grass Valley, California, May 17, 2016
On May 17, 2016 at about 11:30 pm local time, a 2016 amateur-built ZODIAC, registered N99SZ, was destroyed in an accident during landing near Grass Valley, California (Nevada County Air Park airport). It was a personal flight under general aviation rules (Part 91). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's failure to maintain a stabilized approach and landing, which resulted in a hard landing, loss of directional control, runway excursion, and collision with a parked airplane.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 17, 2016 · about 11:30 pm local time
- Place
- Grass Valley, California · Nevada County Air Park · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built ZODIAC 601 HDS, built 2016
- Registration
- N99SZ · no longer on the register · serial 6-3029
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot of an experimental amateur built airplane reported that he felt pressured by a trailing airplane while in the traffic pattern; he further reported that this pressure caused him to turn base, and then final sooner than expected, which resulted in an increased airspeed and higher than expected altitude on final approach. The pilot reported that he decided to proceed with the landing with the intent of utilizing the length of the runway to reduce the airspeed. He further reported that the landing flare was effected by the higher than normal airspeed, and resulted in a hard landing. During the landing roll, the pilot reported that the airplane began to veer to the left and right which progressively increased, resulting in a runway excursion to the left. During the runway excursion, the airplane impacted a taxiway sign, which disabled the brake(s). The airplane continued across the airport until it impacted a parked airplane on the ramp. As a result of the impact, a post-impact fire ensued and the airplane was destroyed.
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
- Preflight or dispatch event during prior to flight
- Loss of control on ground during landing defining event
- Hard landing during landing (flare/touchdown)
- Runway excursion during landing (landing roll)
- Collision with terrain or object (not controlled flight into terrain) during landing (landing roll)
- Ground collision during landing (landing roll)
The NTSB's findings
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Directional control › Not attained/maintained
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Airspeed › Incorrect use/operation
- Environmental issues › Conditions/weather/phenomena › Wind › Tailwind › Awareness of condition
- Environmental issues › Physical environment › Object/animal/substance › Sign/marker › Contributed to outcome
- Environmental issues › Physical environment › Object/animal/substance › Aircraft › Contributed to outcome
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 373 hours in all; 16 in this make and model; 16 in the last 90 days; 6 in the last 30 days; 317 as pilot in command
- Last flight review: February 16, 2016
- Medical certificate: Sport Pilot
- Seat: left
- Injury: minor injuries
The aircraft
- Airframe total time: 18.8 hours
- Last inspection: condition inspection, January 2, 2016
- Maximum gross weight: 1,320 lb
- Seats: 2
- Landing gear: fixed
- Engine: Continental O-200-A (piston); 5,642 hours total
- Fire on the ground
The flight
- Departed from: GOO Grass Valley CA at 9:30 pm
- Destination: GOO Grass Valley CA
- Flight plan: none
- Runway 25, 4,351 ft by 75 ft
Weather at the time
- Light: daylight
- Wind: from 030° at 9 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 79°F (26°C), dew point 37°F (3°C)
- Altimeter: 30.01 inHg
- Observation at 1:20 am from KGOO
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.