What happened
On July 12, 2025, at approximately 1322 mountain daylight time, a Piper PA-25, registration N8186K, was involved in an accident near Hot Springs, South Dakota, while operating as a Part 91 glider aerotow flight. The accident resulted in 1 fatality.
During the flight, the glider pilot reported that after liftoff, the glider reached 1,500 feet agl in a higher-than-normal tow position due to updrafts. The glider pilot attempted to release from the tow rope by pulling the release knob twice, but did not feel the rope disconnect. The glider pilot subsequently determined the aircraft had separated from the rope and performed a landing on runway 19 at the airport.
A witness observed the towplane and glider in a climbing left turn at an altitude of approximately 500 to 600 feet agl. The witness noted the glider appeared to get "extremely high," after which the towplane pitched down. The towplane did not recover from the nose-down attitude and impacted terrain about one mile north of the departure end of runway 6 at Hot Springs Municipal Airport. The impact occurred on a gravel pit embankment, and a post-accident fire occurred. The aircraft impacted the terrain in an estimated 50-degree nose-down pitch.
The investigation
Investigators examined the wreckage of the N8186K and found all primary flight control surfaces and flaps remained attached. The tow rope release latch and cable were continuous from the cockpit to the tail; the latch was found in the open position, and the tow rope attachment ring was located 15 feet from the latch.
The engine's two-blade propeller remained attached to the crankshaft. One blade showed an S-shaped bend and twisting near the tip, and both blades exhibited gouges and scratches. The throttle was found near the idle position, the carburetor heat was off, and the mixture was in a mid-range setting. No engine anomalies were found that would have prevented normal operation.
At the glider's location, investigators found a 7-foot section of yellow rope consistent with a "weak link" portion of a tow rope. This section featured a metal ring on one end and a broom straw separation on the eye splice end. Examination of the glider's tow hook release knob revealed it required approximately 22 lbs of force to release the mechanism, and the release cable was heard binding in its metal conduit. In contrast, a tested exemplary glider release knob required only 4 lbs of force and did not exhibit binding.