What happened
On September 12, 2023, an EV-97 EUROSTAR SL ultralight aircraft, registration OK-OUR, was performing training circuits at the Hořovice (LKHV) aerodrome. The crew, consisting of a student pilot and an instructor, had completed several successful training laps. Following a landing on runway 24, the aircraft took off again, climbing along the runway heading.
At an altitude of approximately 50 meters AGL, the aircraft ceased its climb and entered a 180-degree right turn. During this maneuver, the aircraft lost airspeed, resulting in a wing drop and a subsequent right-hand spin. The aircraft struck a garden shed on the southern edge of the village of T/lustice at a steep angle. The impact caused the total destruction of the forward and middle fuselage and both wing halves. Despite immediate medical intervention at the scene, both occupants sustained fatal injuries.
The investigation
The ÚZPLN investigation examined the aircraft's technical condition, the crew's qualifications, and the environmental factors. Investigators analyzed data from the instructor's mobile phone, airport security camera footage, and witness statements. Technical examinations of the wreckage and engine components revealed no mechanical failures in the aircraft's control surfaces or engine systems. However, fuel samples were found to be contaminated with mechanical impurities, which likely caused the engine to run irregularly.
Findings
- The aircraft's takeoff weight exceeded the maximum takeoff weight (MTOW) by more than 97 kg, and the center of gravity was outside the permitted limits.
- The instructor was operating the aircraft while under the influence of alcohol, with a blood alcohol concentration of 0.77 g/kg.
- The instructor failed to maintain the required descent speed of 110 km/h specified in the flight manual during the engine irregularity.
- The instructor made the improper decision to execute a 180-degree turn immediately after takeoff while the aircraft was overloaded.
- Contaminated fuel likely caused the engine's irregular performance during the critical phase of flight.
- The student pilot lacked sufficient experience on this aircraft type and was likely flying under the instructor's direction.
Safety action
- The ÚZPLN recommends that the Lightweight Aircraft Association of the Czech Republic (LAA ČR) implement a unified methodology for the ongoing monitoring of ultralight pilot training at flight training centers.