N524SL

On July 28, 2025, about 1537 central daylight time, an Ayres Corporation S2R-T34 airplane, N524SL, sustained substantial damage when it was involved in an accident near Akron, Iowa. The pilot sustained serious injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 137 agricultural flight.

The purpose of the low-level aerial application flight was to apply liquid chemical to a field of corn in a rural area. The airplane departed from the Sioux County Regional Airport (SXK), Maurice, Iowa, about 1456. After the completion of the aerial application work, the intent was to return to SXK. At the time of departure, the airplane had about 175 gallons of Jet A fuel on board and about 422 gallons of a mixture of AccuDrop, Aproach Prima, and Lamda-CY AG in the hopper. When the airplane arrived at the field, the pilot maneuvered the airplane for two reconnaissance passes, to identify any obstacles, wires, and sensitive areas to avoid.

After verifying the engine power settings, he began the aerial application work. After several spray passes, the pilot maneuvered the airplane to turn for another spray pass to the north, when the engine sustained a total loss of power. The pilot reported the total loss of engine power occurred about 70 ft above ground level, and the engine “sounded like it exploded.” Prior to the total loss of power, there were no indications of abnormal performance from the engine.

The pilot immediately brought the airplane to a level attitude and began to troubleshoot the emergency. The pilot quickly scanned the cockpit instruments and observed the torque (TQ) indication was below 30 psi and the inter-turbine temperature (ITT) indication was well below 700° Celsius. The pilot pushed the propeller lever forward to obtain a response from power lever inputs. No response was received, so he pulled the propeller lever to the feather position, and he felt the airplane begin to glide.

Directly in the airplane’s flight path was a house and a church, so the pilot decided not to perform an emergency hopper dump to prevent possible chemical exposure to any ground personnel. Additionally, beyond the house and church, the concern was that if an emergency hopper dump was performed, the resulting increase in altitude may cause the airplane to land near other homes, farm buildings, and wires on the other side of the field. The pilot reported the decision not to perform an emergency hopper dump was a calculated decision to avoid injury to ground personnel and to avoid damage to property.

The pilot maneuvered the airplane to a nearby soybean field to perform the forced landing. The pilot was able to land the airplane to the field. During the landing roll, the main landing gear dug into the wet ground and the airplane nosed over. The pilot released himself from the 4-point restraint system he was utilizing and egressed from the inverted airplane via the fractured left window. The pilot then walked to a nearby home for assistance.

The airplane sustained substantial damage to both wings, the fuselage, and the empennage. The airplane was recovered from the accident site, and it was transported to a secure location for future examination.

The pilot was utilizing an airplane flight helmet with a visor, and he reported that the sun did not interfere with his vision during the forced landing. Additionally, he reported that he did not feel fatigued during the accident flight.

Prior to the accident occurring, the pilot reported there were no known issues with the airplane. On May 15, 2025, at a total of 1,073.1 hours since overhaul, the engine had an annual inspection performed by a mechanic. On May 16, 2025, at a total of 13,268.4 airframe hours, the airframe had an annual inspection performed by a mechanic.

The operator, Crop Dusters LLC, based at SXK, utilizes a fleet of Ayres Corporation S2R series airplanes for aerial application work.

The airplane, known as a Turbo Thrush, was manufactured in 1994 and has a 500-gallon capacity hopper. The airplane is a dual cockpit configuration, with two tandem seats. The Federal Aviation Administration (FAA) Type Certificate for the airplane, A4SW, is currently held by Thrush Aircraft, LLC, Albany, Georgia. The airplane was equipped with a Pratt & Whitney Canada PT6A-34AG turboprop engine. The airplane was also equipped with a Hartzell Propeller HC-B4TN-3C/T10702NS four-blade controllable pitch aluminum propeller.

The FAA-approved airplane flight manual discusses the indications of an engine flameout and states in part:

The indications of an engine flameout will be a drop in the inter-turbine temperature, a drop in the torque pressure, and a drop in RPM. The flameout may result from the engine running out of fuel or possibly caused by an unstable engine operation.

The calculated density altitude for the closest meteorological reporting station was 3,615 ft.