Facts
On 5 July 2020 at 15:15 UTC, a TL-2000 Sting S4 ultralight aircraft, registration S5-PGC, operated by Letalski center Maribor, was involved in an accident near the village of Spodnja Gorica, Slovenia. The aircraft was on a private VFR training flight in VMC conditions. The crew consisted of a flight instructor and a student pilot. Both were uninjured. The aircraft was substantially damaged, particularly in the nose section, during an emergency landing aided by a BRS (Ballistic Recovery Systems) parachute.
Flight Sequence
The aircraft departed Maribor Airport (LJMB) at 15:00 UTC for a training area. According to the crew, after arrival the student began performing climbing and descending turns. The instructor then demonstrated a stall without flaps and with engine power reduced. The first stall demonstration at 3000 feet AMSL was uneventful. During the second demonstration, at a speed about 10 knots slower (approximately 34 knots), the aircraft lost control and entered an inadvertent spin with multiple turns. The instructor attempted spin recovery, including adding power to increase airflow over the tail surfaces, but was unsuccessful. He then shut down the engine and activated the BRS parachute. The aircraft stabilized and landed on a wheat field about 5 km south of Maribor Airport. Due to a higher vertical descent rate, the forward structure sustained significant damage. The crew exited the aircraft on their own. The instructor notified the emergency center and the airport manager, who informed Maribor air traffic control. The Slovenian aircraft accident investigation authority and police arrived on scene to document and collect evidence.
Investigation Findings
The investigation included examination of the pitot-static system, mass and balance calculations, and aerodynamic effects of aileron deflection with the control stick neutral. The aircraft was equipped with a GPS logger, whose data were retrieved. Weather at the time was reported as light variable wind, CAVOK, temperature 29°C, dew point 12°C, and QNH 1015 mb. The aircraft's pilot held a flight instructor license. A detailed analysis of the events was conducted, but no probable cause was explicitly stated in the provided report excerpt.