Incident Overview
On April 21, 2017, at approximately 1300 central daylight time, an Air Tractor AT602 agricultural airplane, registration N653LA, conducted a forced landing near Vidrine, Louisiana. The pilot reported no injuries, and the airplane was substantially damaged during the landing. The aircraft was registered to and operated by Central Farmers Cooperative dba Central Farmers Flying Service under 14 Code of Federal Regulations Part 137 as an aerial application flight. Visual meteorological conditions prevailed at the time of the incident.
Pilot Report
The pilot stated he was conducting spray operations when he noticed that during turns, the fuel pressure would vary from 19 to 20 psi. Although this variance was not observed previously, the pilot considered it normal at the time. During a subsequent turn, the engine lost power. The pilot activated the fuel boost pump and engine ignitor, but the engine did not restart. He then executed a forced landing in a rice field.
Post-Landing Observations
During the landing, the airplane struck several levees, resulting in the main landing gear being torn off and the aircraft coming to rest on its belly. The pilot inspected the fuel tanks and reported visible fuel in both left and right tanks. Two individuals who arrived to assist stated there was 3 to 4 inches of fuel in each tank, and fuel was leaking from the tanks.
An FAA inspector noted substantial damage to the left and right wings. Upon arrival, the fuel tanks were empty, but it appeared both tanks had been breached and leaked their contents onto the ground.
Examination Findings
The airplane was partially dismantled, including removal of the wings, for recovery and later transported to a repair facility. An examination was conducted by an NTSB Investigator-in-Charge and a technical representative from the airframe manufacturer.
The engine fuel lines, including the Py line, were inspected and showed no apparent damage or leaks. The airframe fuel filter, located on the firewall, was opened and found to be full of fuel. The engine high-pressure fuel pump filter bowl was opened, revealing a fuel level about one inch below the top; no debris or contaminants were present. Approximately 1 quart of fuel was drained from the airplane's fuel header tank, and the fuel appeared clean.
Without electrical power and with the wings removed, the left and right fuel gauges indicated approximately 1/16 inch and 1/8 inch above empty, respectively. After applying electrical power, a self-test on the Shadin fuel flowmeter was successful. The unit displayed 52.1 for fuel remaining and 157 for fuel used. The airplane was equipped with a 210-gallon fuel system. The flowmeter does not have fuel level sensing capability; it subtracts fuel from the amount input by the pilot. The flowmeter had been programmed to 209 at the last refueling or instrument reset.
Engine Test
The engine was separated from the airframe and sent to an overhaul/repair facility. Prior to overhaul, the engine was placed in an engine test cell under the supervision of an FAA inspector. The engine started and ran with no abnormalities noted.
Conclusion
A reason for the loss of engine power was not found.