Incident Overview
The Federal Safety Investigation Office (Sicherheitsuntersuchungsstelle des Bundes) issued an interim report regarding the accident of a motor glider classified as a heavier-than-air aircraft. The incident involved an Evektor EV-97 SportStar RTC, operated by a Slovenian training organization and owned by a limited liability company. The accident occurred on October 4, 2023, at approximately 16:03 UTC, in the locality of Bösenort, within the municipality of Diex, Carinthia, Austria.
Flight Progression and Failure Sequence
The aircraft departed Maribor (LJMB) at 15:26 UTC for a solo training flight intended to build flight hours. The pilot, holding a Slovenian Private Pilot License, was accompanied by another trainee. After entering Austrian airspace near the RADLY reporting point, the crew encountered rain showers and increasing cloud cover. Due to sunset times in both Maribor and Klagenfurt, the original plan to land or overfly Klagenfurt was abandoned in favor of an immediate return to Maribor.
At approximately 15:58 UTC, while climbing to 10,000 feet MSL, the engine oil temperature began to drop significantly, falling from the green range to approximately 89°C and later to 71°C, despite a constant oil pressure of 3.65 bar. At 16:01 UTC, the engine RPM increased noticeably while fuel flow remained constant. Shortly after, at 16:02 UTC, the aircraft experienced an abrupt loss of power, a drop in oil pressure to the red zone, and a complete cessation of propeller rotation and fuel flow.
Loss of Control and Impact
Following the total engine failure, the aircraft entered a steep climb with a nose-up attitude of approximately 40 degrees. The pilot initiated a left turn, but the aircraft lost speed and entered an uncontrolled stall. This developed into a spin, causing a rapid altitude loss to approximately 4,000 feet MSL. Although the pilot managed to recover from the spin, the aircraft remained in a stalled condition with low airspeed. Control inputs to lower the nose were ineffective, and the aircraft impacted hard on a mowed meadow at the accident site before sliding down a slope to its final resting position.