Amateur-built Coot A-Amphib accident near San Andreas, California, November 23, 2012
On November 23, 2012 at about 11:30 pm local time, a amateur-built Coot A-Amphib, registered N8VS, was substantially damaged in an accident during maneuvering near San Andreas, California (Calaveras Co-Maury Rasmussen airport). It was a personal 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 excessive flight control inputs, which led to flight that exceeded the structural limits of the airplane and resulted in structural failure of both wings.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- November 23, 2012 · about 11:30 pm local time
- Place
- San Andreas, California · Calaveras Co-Maury Rasmussen · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built Coot A-Amphib
- Registration
- N8VS · no longer on the register · serial Sater Coot #1
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
A witness observed the airplane in a steep bank (estimated at between 60 and 80 degrees) while turning from the base leg to final approach in the traffic pattern. He then observed the airplane enter a spin and stated the airplane was in a near vertical nose-down attitude when the right wing separated from the airframe. Another witness reported that after the airplane’s first spin revolution, the leading edge came off of a wing and that during the second spin revolution the other wing separated. A postaccident examination of the airplane revealed that both wings had separated from the airplane about the same spanwise location (about 17 inches outboard of the wing attach points). The right wing’s front spar fracture face showed areas of tension and compression failures of the wood fibers that were consistent with the wing failing in a downward direction. Both the leading edge and front spar of the left wing had diagonal cuts through them that were consistent with having been struck by the airplane’s propeller. The inboard front spar fracture face was examined, but the fiber failures were destroyed by the ground impact, so a directionality of failure could not be determined. However, the propeller strike on the leading edge and front spar could only occur if the left wing failed upward into the propeller. There were no obvious signs of rot or preexisting conditions in the wood spars examined, and none of the wing attachment bolts failed. The witness reports indicating that the airplane was in a continuous steepening turn from the downwind leg to final approach immediately before the accident and the observed damage suggest that the pilot’s control inputs stressed the airplane’s wings beyond their design capabilities.
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
- Aircraft structural failure during maneuvering defining event
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
The NTSB's findings
- cause Aircraft › Aircraft structures › Wing structure › (general) › Capability exceeded
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
Pilot
- Certificate: private
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 5,138 hours in all
- Last flight review: April 27, 2008
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: left
- Injury: fatal
The aircraft
- Last inspection: inspection type not recorded
- Maximum gross weight: 1,950 lb
- Seats: 2
- Landing gear: fixed
- Engine: Franklin 6A&6V335 (piston); 0 hours total
The flight
- Departed from: CPU San Andreas CA at 11:30 pm
- Destination: CPU San Andreas CA
- Flight plan: none
- Runway 31, 3,603 ft by 60 ft
Weather at the time
- Light: daylight
- Wind: from 290° at 5 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 64°F (18°C), dew point 52°F (11°C)
- Altimeter: 30.18 inHg
- Observation at 11:55 pm from SCK, 30 miles away
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.