What happened
On February 2, 2024, a tandem paraglider flight was being conducted for adventure tourism in the Las Vizcachas area, near Puente Alto, Chile. The flight involved a pilot and one passenger using an AIRDESIGN GmbH RIDE 3 ultralight aircraft. The takeoff was planned from a designated area on the northwest slope of Cerro Banco.
During the takeoff sequence, after the wing had been inflated, the pilot attempted to maintain control of the canopy. However, the aircraft was suddenly struck by a localized thermal turbulence phenomenon, known locally as a "diablito." This sudden gust caused the wing to collapse, tilting approximately 70 degrees to the right and then rotating 80 degrees to the left, leaving the top surface of the wing parallel to the ground. This loss of lift caused the wind to push the aircraft across the takeoff platform, dragging both the pilot and the passenger off the edge of the slope. The occupants fell approximately 10 to 15 meters, impacting trees and shrubs.
The investigation
DGAC Chile examined the circumstances surrounding the takeoff, the meteorological conditions, and the maintenance status of the aircraft. The investigation confirmed that the passenger had received a safety briefing and had signed a risk acceptance document prior to the flight. Both occupants were wearing protective helmets, and the pilot's seat was equipped with an emergency parachute.
The investigation also reviewed the meteorological data provided by the Chilean Meteorological Directorate (DMC), which corroborated the presence of unpredictable thermal turbulence at the time of the event. Regarding the aircraft, while the investigation found no structural damage or mechanical failures that contributed to the incident, the owner could not demonstrate that the required 12-month or 150-hour inspections had been performed according to the manufacturer's manual. Additionally, the operator was not in possession of the required identification and control document for the ultralight vehicle.
Findings
- The primary cause of the incident was the loss of ground control of the ultralight aircraft during the takeoff maneuver.
- An unforeseen meteorological phenomenon, specifically a thermal turbulence burst ("diablito"), destabilized the wing.
- The sudden wind force caused the wing to collapse and rotate, leading to a loss of lift.
- The aircraft was dragged across the takeoff surface, resulting in the occupants falling down the hillside.
- The passenger sustained minor injuries, while the pilot remained uninjured.
- The AIRDESIGN GmbH RIDE 3 aircraft sustained no damage.