What happened
On January 14, 2022, at approximately 19:30 local time, a Kraft motorized ultralight (ULM) paratrike was conducting a commercial flight over Lake Villarrica, near Pucón, Chile. The aircraft, which was not registered with the DGAC, was performing maneuvers at an altitude of roughly 100 meters when the main wing suffered a structural failure.
As the pilot executed sharp turns and steep climbs and descents, a tear developed in the wing's fabric, causing the wing to collapse. The aircraft entered an uncontrolled vertical descent toward the water. Although the pilot deployed the emergency parachute shortly before impact, it only partially deployed, failing to sufficiently mitigate the force of the crash. The aircraft struck the lake surface with high energy. The pilot escaped without injury, but the passenger sustained serious injuries, including fractures to the left ankle and right knee.
The investigation
DGAC Chile investigators examined the wreckage and the takeoff site to determine the sequence of events. The investigation focused on the condition of the Kraft aircraft, the pilot's credentials, and the integrity of the wing fabric.
Investigators found that the aircraft was not recorded in the DGAC registry, meaning the operator was not in compliance with local ULM regulations. The inspection of the wing revealed a continuous tear running from the trailing edge to the leading edge. Furthermore, the investigation looked into the takeoff area, which was an unprepared private field characterized by irregular terrain and vegetation.
Findings
- The primary cause of the accident was the tearing of the wing fabric during flight, which led to a total loss of lift and an uncontrolled descent.
- The tear originated at the trailing edge, where the fabric had been previously degraded by fraying, loose threads, and wear.
- The pilot performed aggressive maneuvers that subjected the wing to excessive aerodynamic loads, exceeding the strength of the already weakened fabric.
- The takeoff and landing site consisted of unprepared ground with loose debris and vegetation, which had caused physical damage to the wing during previous operations.
- The pilot failed to perform a pre-flight inspection, which would have allowed for the detection of the fabric's deteriorated condition.
- There was no documented maintenance history available to verify the airworthiness of the aircraft or the wing.
- The pilot was operating the aircraft without a valid license.
Safety action
Following the investigation, the DGAC emphasized the need for ULM owners and pilots to strictly adhere to aeronautical regulations, including mandatory registration and maintenance schedules. Safety recommendations include ensuring that takeoffs and landings occur only on surfaces free of debris that could damage the wing, and avoiding high-load maneuvers that could compromise the structural integrity of older or worn wing fabric.