The U.S. aircraft register, updated daily
Accidents · NTSB WPR24FA123 · Final report

Ayres Corporation S2R-G10 accident near Derner, California, April 9, 2024

On April 9, 2024 at about 9:44 pm local time, a 1999 Ayres Corporation S2R-G10, registered N40261, was substantially damaged in an accident during maneuvering (low-alt flying) near Derner, California. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 1 person was killed. The weather was visual conditions (good weather).

The NTSB's probable cause their words, unchanged

The pilot’s failure to adequately monitor his fuel supply, resulting in fuel exhaustion, a total loss of engine power, and the airplane’s impact with terrain.

Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.

What the record shows

Date
April 9, 2024 · about 9:44 pm local time
Place
Derner, California · map
Type
Accident
Injuries
1 person was killed.
Weather
visual conditions (good weather)
Aircraft
Ayres Corporation S2R-G10, built 1999 · all S2R-G10s on the register
Registration
N40261 · registry record · serial G10-158
Damage
Substantial damage
Flight
Aerial application (crop spraying) flight · agricultural flying rules (Part 137)

The NTSB's narrative final · quoted from the NTSB record

On the morning of the accident, the pilot departed from the operator’s base and flew the airplane about 174 miles northeast, to an airstrip near a rice farm. About 1230, after performing multiple flights to drop wild rice in the paddies near the airstrip, the pilot asked the fuel truck operators to fuel the airplane until the tanks were 3/4 full and subsequently departed the airstrip to continue spreading rice. When the pilot returned to the airstrip about 1400, he said he was not feeling well and was going to apply one last load of rice before leaving work. The pilot declined to have more fuel added to the fuel tanks. The pilot was seen with his safety harnesses fastened when he last departed. About 1444, witnesses near the rice farm heard the airplane crash and saw it inverted and partially submerged in the rice paddy. When they opened the airplane’s canopy, they found the pilot unbuckled from the safety harness, unresponsive. Examination of the airplane revealed an unusable amount of fuel (less than 2 gallons) in the fuel system, and no fuel sheen was observed in the water. No preaccident mechanical failures or malfunctions that would have precluded normal operation were found. The propeller blade damage signatures at the accident site were consistent with low rotational energy at impact. The airplane’s fuel system was intact, and there was no evidence of fuel leakage. After the pilot departed the operator’s facility, he had texted the mechanic stating the airplane’s fuel gauge was inoperative and that the airplane’s fuel gauge was slower to respond to fuel quantity changes than other airplanes. The mechanic explained that the gauge did not read fuel quantities greater than 82 gallons per tank; additionally, the cockpit fuel gauge noted that fuel quantities above 82 gallons were “ungageable.” Postaccident testing of the airplane’s fuel gauge and level senders indicated that they were operating to the manufacturer’s specifications. Fuel consumption calculations indicate that, with the reported fuel load, the airplane would have had an endurance of 2.1 to 2.9 hours. Although the airplane sustained substantial damage, the accident appeared to be survivable. The pilot’s autopsy identified no obvious fatal traumatic injuries, and the cause of death was determined to be hypertensive and atherosclerotic cardiovascular disease. However, the accident circumstances provide no clear evidence of in-flight pilot incapacitation, and it is unlikely that the pilot’s cardiovascular disease contributed to the accident. Additionally, severe acute mental or physical stress may be a trigger for cardiac events in individuals with underlying heart disease. It is possible that the airplane’s impact with the water of the rice paddy, followed by it becoming partially submerged and inverted, could have resulted in such a cardiac event in the setting of the pilot’s preexisting heart disease. The lack of fuel at the accident site and onboard the airplane during postaccident examination is consistent with fuel exhaustion, which resulted in the airplane’s impact with terrain. Though the pilot reported he was feeling unwell in the hours before the accident, available evidence is insufficient to determine what specific symptoms he was experiencing, or whether his symptoms contributed to the accident.

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

  1. Fuel exhaustion during maneuvering (low-alt flying) defining event

The NTSB's findings

  • Aircraft › Fluids/misc hardware › Fluids › Fuel › Fluid level
  • Personnel issues › Experience/knowledge › Experience/qualifications › Total experience w/ equipment › Pilot
  • Personnel issues › Physical › Health/Fitness › Physical fitness › Pilot
  • Personnel issues › Task performance › Planning/preparation › Fuel planning › Pilot

Pilot

  • Certificate: commercial pilot
  • Ratings: multi-engine land; single-engine land; rotorcraft: helicopter
  • Flight time: 10,000 hours in all; 5,000 in this make and model; 10,000 as pilot in command
  • Last flight review: January 20, 2023
  • Medical certificate: Class 2 (with waivers/limitations)
  • Seat: sngl
  • Injury: fatal

The aircraft

  • Last inspection: 100-hour inspection
  • Seats: 1
  • Landing gear: fixed
  • Engine: Airesearch TPE331 SERIES (turboprop); 185,489 hours total
  • Operator: Jones Aviation INC

The flight

  • Departed from: Alturas CA at 9:23 pm
  • Flight plan: none

Weather at the time

  • Light: daylight
  • Visibility: 10 statute miles
  • Sky: clear
  • Temperature: 63°F (17°C), dew point 30°F (-1°C)
  • Altimeter: 30.19 inHg
  • Observation at 2:55 pm from KAAT, 39 miles away

Weather report (METAR): KAAT 092155Z AUTO VRB03KT 10SM CLR 17/M01 A3019 RMK AO2 SLP217 T01721006

Injuries

FatalSeriousMinorNone
Flight crew1

Documents from the investigation the NTSB's docket: the evidence folder behind the report

10 documents, released by the NTSB on May 21, 2026. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.

#DocumentWhat it is
1 Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 PDF, 10 pages · our copy View Download
2 Witness Statements PDF, 6 pages · our copy View Download
3 Flight Manual Excerpt PDF, 2 pages · our copy View Download
4 Wreckage Examination Report PDF, 7 pages · our copy View Download
5 Fuel System Component Exam Reports PDF, 3 pages · our copy View Download
6 Investigation Photographs PDF, 4 pages · our copy View Download
7 Global Positioning System Device - Specialist's Factual Report PDF, 5 pages · our copy View Download
8 Global Positioning System Device - Specialist's Factual Report - ATTACHMENT1 - Tabular Data data file · our copy Download
9 Party Form- Honeywell PDF, 1 page · our copy View Download
10 Medical Factual Report PDF, 9 pages · our copy View Download

The same docket at the NTSB.

About this page

Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number WPR24FA123.