What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Synopsis on August 10, 2025, at approximately 1321 CDT, agricultural aircraft privacy data omitted was involved in a takeoff accident at Klein-Oneal Airport (IL16) in Lawrenceville, Illinois. While departing runway 30, the aircraft failed to achieve sufficient airspeed and lift, ultimately impacting terrain in a bean field beyond the runway. The pilot exited without serious injury, but the aircraft sustained substantial damage.
Causal and contributing factors
• Power loss during takeoff: the pilot initially set torque at 1,700 lbs., which dropped unexpectedly to 1,400 lbs. Despite firewalling the throttle, no increase in power occurred.
• Obstructed emergency dump valve: the pilot attempted to jettison the chemical load to reduce weight but was unable to activate the dump valve. A runner handle had slid upward, covering the button and preventing its use.
• Flap deployment: full flaps were deployed prematurely, causing excessive drag and impairing climb performance. The aircraft briefly gained altitude before impacting terrain. The flight manual warns against full flap use during takeoff.
• Environmental conditions: a density altitude of approximately 2,221 feet and ambient temperature of 31°c likely contributed to reduced aircraft performance.
Root cause analysis primary causes of the accident included:
• Unresolved power reduction during takeoff
• Inability to jettison chemical load, increasing weight
• Full flap deployment at low airspeed, increasing drag and reducing lift - contrary to flight manual
Contributing factors:
• Elevated temperature and density altitude
Investigation summary emergency crews responded promptly, and no serious injuries were reported. At 1545 CDT, the FAA was notified. That evening, the inspector-in-charge (iic) and a second inspector traveled to the accident site, arriving at 8:25 pm. The aircraft had been relocated near the hangar. Inspectors photographed the aircraft, interviewed the pilot, and retrieved GPS data. A fuel sample showed no contamination. Flaps were found fully deployed, and the dump valve was confirmed obstructed by the runner handle.
At 9:50 pm, inspectors departed after requesting documentation from the pilot, including identification, certificates, logbook entries, and maintenance records. Between August 11–14, the investigation continued via email and phone. The pilot’s documentation was verified and found compliant with 14 CFR regulations. Weight and balance data showed the aircraft was 400 lbs. Below its maximum takeoff weight.
The pilot stated he initially set 10° flaps and later deployed full flaps to gain lift and avoid a potential road hazard. Photo evidence confirmed flap position and obstruction of the dump valve. He also reported a torque drop from 1,700 to 1,400 lbs. With no response to full throttle. The flight manual describes this as a possible malfunction in the fuel control unit’s pneumatic or governor section. The aircraft lacked a manual fuel control override (fcu override).
Conclusion the accident was caused by a combination of mechanical failure, operational decisions, and environmental conditions. A torque drop, inability to jettison the chemical load, and premature flap deployment led to insufficient thrust and lift. The aircraft impacted terrain beyond the runway and came to rest inverted.
No regulatory violations were immediately identified. The incident highlights the importance of:
• Ensuring emergency systems are unobstructed
• Monitoring engine performance and aborting takeoff if anomalies arise
• Avoiding premature full flap deployment during takeoff
• Considering density altitude in performance planning
As the FAA filed it
SYNOPSIS ON AUGUST 10, 2025, AT APPROXIMATELY 1321 CDT, AGRICULTURAL AIRCRAFT ^PRIVACY DATA OMITTED^ WAS INVOLVED IN A TAKEOFF ACCIDENT AT KLEIN-ONEAL AIRPORT (IL16) IN LAWRENCEVILLE, ILLINOIS. WHILE DEPARTING RUNWAY 30, THE AIRCRAFT FAILED TO ACHIEVE SUFFICIENT AIRSPEED AND LIFT, ULTIMATELY IMPACTING TERRAIN IN A BEAN FIELD BEYOND THE RUNWAY. THE PILOT EXITED WITHOUT SERIOUS INJURY, BUT THE AIRCRAFT SUSTAINED SUBSTANTIAL DAMAGE.
CAUSAL AND CONTRIBUTING FACTORS
• POWER LOSS DURING TAKEOFF: THE PILOT INITIALLY SET TORQUE AT 1,700 LBS., WHICH DROPPED UNEXPECTEDLY TO 1,400 LBS. DESPITE FIREWALLING THE THROTTLE, NO INCREASE IN POWER OCCURRED.
• OBSTRUCTED EMERGENCY DUMP VALVE: THE PILOT ATTEMPTED TO JETTISON THE CHEMICAL LOAD TO REDUCE WEIGHT BUT WAS UNABLE TO ACTIVATE THE DUMP VALVE. A RUNNER HANDLE HAD SLID UPWARD, COVERING THE BUTTON AND PREVENTING ITS USE.
• FLAP DEPLOYMENT: FULL FLAPS WERE DEPLOYED PREMATURELY, CAUSING EXCESSIVE DRAG AND IMPAIRING CLIMB PERFORMANCE. THE AIRCRAFT BRIEFLY GAINED ALTITUDE BEFORE IMPACTING TERRAIN. THE FLIGHT MANUAL WARNS AGAINST FULL FLAP USE DURING TAKEOFF.
• ENVIRONMENTAL CONDITIONS: A DENSITY ALTITUDE OF APPROXIMATELY 2,221 FEET AND AMBIENT TEMPERATURE OF 31°C LIKELY CONTRIBUTED TO REDUCED AIRCRAFT PERFORMANCE.
ROOT CAUSE ANALYSIS PRIMARY CAUSES OF THE ACCIDENT INCLUDED:
• UNRESOLVED POWER REDUCTION DURING TAKEOFF
• INABILITY TO JETTISON CHEMICAL LOAD, INCREASING WEIGHT
• FULL FLAP DEPLOYMENT AT LOW AIRSPEED, INCREASING DRAG AND REDUCING LIFT - CONTRARY TO FLIGHT MANUAL
CONTRIBUTING FACTORS:
• ELEVATED TEMPERATURE AND DENSITY ALTITUDE
INVESTIGATION SUMMARY EMERGENCY CREWS RESPONDED PROMPTLY, AND NO SERIOUS INJURIES WERE REPORTED. AT 1545 CDT, THE FAA WAS NOTIFIED. THAT EVENING, THE INSPECTOR-IN-CHARGE (IIC) AND A SECOND INSPECTOR TRAVELED TO THE ACCIDENT SITE, ARRIVING AT 8:25 PM. THE AIRCRAFT HAD BEEN RELOCATED NEAR THE HANGAR. INSPECTORS PHOTOGRAPHED THE AIRCRAFT, INTERVIEWED THE PILOT, AND RETRIEVED GPS DATA. A FUEL SAMPLE SHOWED NO CONTAMINATION. FLAPS WERE FOUND FULLY DEPLOYED, AND THE DUMP VALVE WAS CONFIRMED OBSTRUCTED BY THE RUNNER HANDLE.
AT 9:50 PM, INSPECTORS DEPARTED AFTER REQUESTING DOCUMENTATION FROM THE PILOT, INCLUDING IDENTIFICATION, CERTIFICATES, LOGBOOK ENTRIES, AND MAINTENANCE RECORDS. BETWEEN AUGUST 11–14, THE INVESTIGATION CONTINUED VIA EMAIL AND PHONE. THE PILOT’S DOCUMENTATION WAS VERIFIED AND FOUND COMPLIANT WITH 14 CFR REGULATIONS. WEIGHT AND BALANCE DATA SHOWED THE AIRCRAFT WAS 400 LBS. BELOW ITS MAXIMUM TAKEOFF WEIGHT.
THE PILOT STATED HE INITIALLY SET 10° FLAPS AND LATER DEPLOYED FULL FLAPS TO GAIN LIFT AND AVOID A POTENTIAL ROAD HAZARD. PHOTO EVIDENCE CONFIRMED FLAP POSITION AND OBSTRUCTION OF THE DUMP VALVE. HE ALSO REPORTED A TORQUE DROP FROM 1,700 TO 1,400 LBS. WITH NO RESPONSE TO FULL THROTTLE. THE FLIGHT MANUAL DESCRIBES THIS AS A POSSIBLE MALFUNCTION IN THE FUEL CONTROL UNIT’S PNEUMATIC OR GOVERNOR SECTION. THE AIRCRAFT LACKED A MANUAL FUEL CONTROL OVERRIDE (FCU OVERRIDE).
CONCLUSION THE ACCIDENT WAS CAUSED BY A COMBINATION OF MECHANICAL FAILURE, OPERATIONAL DECISIONS, AND ENVIRONMENTAL CONDITIONS. A TORQUE DROP, INABILITY TO JETTISON THE CHEMICAL LOAD, AND PREMATURE FLAP DEPLOYMENT LED TO INSUFFICIENT THRUST AND LIFT. THE AIRCRAFT IMPACTED TERRAIN BEYOND THE RUNWAY AND CAME TO REST INVERTED.
NO REGULATORY VIOLATIONS WERE IMMEDIATELY IDENTIFIED. THE INCIDENT HIGHLIGHTS THE IMPORTANCE OF:
• ENSURING EMERGENCY SYSTEMS ARE UNOBSTRUCTED
• MONITORING ENGINE PERFORMANCE AND ABORTING TAKEOFF IF ANOMALIES ARISE
• AVOIDING PREMATURE FULL FLAP DEPLOYMENT DURING TAKEOFF
• CONSIDERING DENSITY ALTITUDE IN PERFORMANCE PLANNING
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.