Rans S-12 Airaile N2757A accident near Concordia, Kansas

Preliminary information

On August 24, 2025, about 1926 central daylight time, a Rans S-12 Airaile airplane, N2757A, was substantially damaged when it was involved in an accident near Concordia, Kansas. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

A witness reported that airplane appeared to have “trouble gaining altitude” and was alternating between a slight climb and descent as it flew to the east. The airplane then turned and was flying to the south when it entered a nose-down spiral descent to the ground.

The same witness captured a cellphone video of the airplane during the final moments of the flight. A preliminary review of the video footage revealed audio evidence that the airplane engine was operating as it entered a progressively steeper left turn toward the east. As the left bank angle increased, the airplane entered a steep nose-down pitch attitude and continued in the spiraling descent toward the ground. There was an abrupt reduction in engine noise after the airplane entered the steep spiraling descent from a low altitude.

According to FAA documentation, the experimental light sport airplane was issued a special airworthiness certificate and registration on November 9, 2007. On the application for the airworthiness certificate, the applicant noted that the airplane was originally manufactured in 1995. At the time of the accident, the airplane’s hour meter indicated 767.2 hours. The maintenance logbooks for the airplane were not located at the accident site or in the pilot’s two hangars that he rented at Blosser Municipal Airport, Concordia, Kansas.

The airplane wreckage was located at the edge of a soybean field and a residential backyard. The airplane came to rest underneath power lines that were not damaged during the accident. The airplane’s nose was facing east. All major structural components and flight controls were identified at the accident site. The airplane fuselage and both wings exhibited substantial impact-related damage. The forward portion of the fuselage and nose cone fragmented during impact with terrain. The airframe’s steel-tube fuselage exhibited multiple fractures and bends consistent with impact-related damage. The instrument panel was fractured with multiple instruments found separated from the panel. Both seats sustained impact-related damage. The empennage remained attached to the tubular tailboom. The tailboom remained attached to the fuselage structure. The vertical and horizontal stabilizers appeared undamaged. The elevator, rudder, and pitch trim tab remained attached to their respective hinge points. The ailerons and flaps remained attached to their respective wing hinge points.

The postaccident examination did not reveal any evidence of a flight control system component failure. Rudder control cable continuity was confirmed from the cockpit rudder pedals to the rudder horn. Elevator control push/pull tube continuity was confirmed from the control surface to the cockpit where the control tube exhibited a 90° upward bend and fractured rod end consistent with impact-related damage. Aileron flight control cable continuity was confirmed from the cockpit controls to the forward bellcrank where it transitioned to a push/pull control tube to each wing and its respective aileron. Aileron push/pull control tube continuity was confirmed from the forward bellcrank to each aileron. Flap cable control continuity was confirmed from the cockpit flap handle to each wing flap. The wing flaps were found fully retracted after the accident.

Each wing was equipped with a 5-gallon fuel tank that contained ample fuel. The odor of the fuel was consistent with auto-fuel. The fuel exhibited a light blue coloration consistent with 2-cycle engine oil premix. Fuel was present in the fuel lines to the engine carburetors.

The engine remained attached to the airframe mounts. The engine did not exhibit any crankcase or cylinder fractures, nor was there any evidence of coolant, fuel, or oil leaks on the exterior engine components and coolant lines. The exhaust remained attached to the engine. Both carburetors remained attached to their respective induction tubes, their respective fuel bowls contained residual fuel, and no contamination was observed in the bowls or fuel screens. Fuel drained from the fuel supply lines to each carburetor. The throttle and choke cables remained attached to their respective cockpit engine controls and were continuous to their respective carburetors. The engine control cables were cut by investigators to facilitate the engine examination. Examination of both carburetors did not reveal any evidence of mechanical failure.

Internal engine drivetrain continuity was confirmed as the engine crankshaft was rotated. The engine crankshaft rotated freely through the propeller. The engine crankshaft was also rotated via the electric starter when connected to a truck battery. Cylinder compression/suction were confirmed in conjunction with crankshaft rotation. The rotating valve was undamaged and functioned normally as the engine crankshaft was rotated. There was no evidence of oil starvation or seizure of the rotating valve.

Each cylinder wall, piston dome, and piston skirt exhibited features consistent with normal engine operation. There was no evidence of piston seizure. The cylinder head exhibited foreign object debris damage to the power-takeoff (PTO) side; however, as previously discussed, the PTO piston and cylinder were not damaged. Additionally, as evidenced by a build-up of carbon deposits, the observed damage to the PTO-side of the cylinder head was consistent with a previous piston failure event. The magneto-side of the cylinder head was undamaged. Residual coolant fluid was present around each cylinder. The externally mounted coolant expansion container contained coolant. The externally mounted injection oiler contained a light gray fluid consistent with water-contaminated lubrication oil. However, as previously discussed, there was no evidence of thermal distress or seizure to any of the oil lubricated engine components including the rotating valve.

The four sparkplugs exhibited features consistent with normal engine operation. There was no evidence of mechanical damage to the sparkplug electrodes. The dual-ignition system was not functionally tested.

The propeller hub remained attached to the reduction gearbox. The carbon-composite propeller blades exhibited damage consistent with engine operation at impact. The propeller blades fractured about 12 inches from their respective blade grips. The three fractured blades were located 24 ft at 095° true, 81 ft at 030° true, and 86 ft at 360° true from the main wreckage.

The examination of the airplane, engine, and propeller revealed no evidence of a preimpact mechanical malfunction or failure that would have prevented normal operation.

Text from the NTSB; a preliminary report can change and names no cause. Open the NTSB docket for CEN25FA339 for the full record.