Overview
On 4 February 2023 at approximately 15:50 UTC (16:50 local time), a TL Ultralight Stream ultralight aircraft, registration OK-XUA 62, crashed into a grass yard near residential houses in the village of Dobravica, municipality of Šentjernej, Slovenia. The aircraft was destroyed by impact and subsequent fire. The pilot, who was the sole occupant, died in the accident.
Flight Details
The pilot departed from Prečna airfield (LJNM) at 16:11 local time and flew directly to the Šentjernej area. Upon arrival over his home town, he began performing maneuvers consisting of steep turns, mostly at altitudes below 300 meters above ground level. The turns were executed in a very tight radius between 150 and 700 meters. The pilot flew concentrated circles over a densely populated part of the town, overflying groups of houses north of Mihovica and near the Šentjernej hippodrome.
At about 16:50 local, while executing a left turn from approximately 080° to 270°, the pilot abruptly changed direction into a right turn with a bank angle exceeding 60°. During the steep right turn, the aircraft lost altitude. The pilot then gradually reduced the bank angle, and the aircraft impacted the ground in a slight right bank of about 10°. The impact site was a grassy yard in close proximity to residential houses in Dobravica. The aircraft caught fire upon impact.
Aircraft and Pilot Information
The aircraft was a TL Ultralight Stream, a two-seat motorized ultralight, serial number 18STR05. It was registered with the Czech light aircraft authority LAA ČR (OK-XUA 62) and held an airworthiness certificate valid until 24 August 2023. The aircraft was classified as amateur-built. Examination of wreckage and aircraft records revealed no abnormalities that could have contributed to the accident.
The pilot held a valid ultralight (ULN) pilot license issued on 25 July 2019 and a valid LAPL medical certificate valid until 12 May 2023. His total flight time at the time of license conversion (25 July 2019) was 513 hours and 17 minutes. His total flight time at the time of the accident is unknown, as his logbook could not be obtained. He had been flying the accident aircraft since 2018 and maintained his qualifications without significant interruptions, typically flying over his home area and in the state of registration for regular maintenance.
Sequence of Events from Witness and Video Evidence
Investigators obtained multiple video recordings and witness statements. The footage confirmed the aircraft performing continuous steep turns at low altitude over the populated area. The final maneuver was a rapid transition from a left turn to a steep right turn with bank exceeding 60°, followed by a loss of altitude and impact.
Meteorological Conditions
Satellite imagery at 10:00 UTC and 13:30 UTC showed cloud cover. Wind data from Cerklje ob Krki airfield and GAFor forecasts were collected but are not cited as contributory.
Conclusion
The investigation determined the probable cause of the accident.
Probable cause: Loss of control during execution of steep turns due to improper pilot handling.