What happened
On May 8, 2016, an Aveko VL-3 E ultralight aircraft was conducting a series of demonstration flights near Mühldorf, Germany, to showcase its performance to potential buyers. During one of these flights, the aircraft departed from the planned flight profile. After reducing engine power to idle, the pilot flew at a high angle of attack, leading to a stall of the right wing. The aircraft subsequently entered a spin.
As the aircraft descended, the pilot attempted to recover, but the maneuver resulted in an uncontrolled spiral. The aircraft's emergency parachute system was deployed, but because the activation occurred at an altitude of less than 50 meters, the canopy could not fully inflate. The aircraft struck an agricultural field near Teising with a significant pitch angle, resulting in two fatalities.
The investigation
The BFU examined the aircraft's flight data from a Garmin multifunction display, which revealed that the aircraft had been flying at a high angle of attack with reduced power prior to the stall. The investigation also analyzed the aircraft's weight and balance, finding that the total takeoff mass was 519 kg, significantly exceeding the maximum allowable takeoff weight of 472.5 kg.
Investigators also scrutinized the aircraft's equipment, noting the presence of an autopilot, which was not listed in the official equipment list and was technically unauthorized for this type of ultralight aircraft under certain regulations. The engine and propeller were inspected, and no mechanical failures were found that could have caused the loss of control. The investigation also reviewed the certification process of the Galaxy GRS 6/473 SD rescue system, noting discrepancies between the manufacturer's testing and the required airworthiness standards.
Findings
- The primary cause of the accident was the aircraft flying below its stall speed, which induced the spin.
- The pilot failed to recover from the spin before impact.
- The aircraft was significantly overweight, with a takeoff mass exceeding the maximum limit by over 45 kg.
- The emergency parachute system was activated at too low an altitude to allow for full deployment and effective deceleration.
- Turbulent weather conditions, characterized by gusty winds and thermals, may have contributed to the aerodynamic instability.
- The weight and balance information was not clearly visible to the pilot, as the load sticker was located in the footwell.