What happened
On June 2, 2018, a pilot operating a Reaction 31 motorized paraglider departed on a flight from Wieliszew toward Serock. The flight was conducted under visual meteorological conditions (VMC) in uncontrolled airspace. After reaching the turning point at Serock, the pilot turned back toward the starting point, maintaining an altitude of approximately 150 meters.
As the aircraft approached the area of Jachranka, the engine experienced a sudden and significant loss of power. Although the engine continued to run, the aircraft began to descend. Fearing the loss of altitude would prevent the pilot from clearing a nearby river, the pilot initiated an emergency landing in a field near Jachlantka. During the descent, the pilot failed to notice medium-voltage power lines. The aircraft struck the lines, severing one cable, and subsequently crashed to the ground. The pilot sustained serious injuries, including second and third-degree burns from an electric shock and a spinal fracture.
The investigation
The PKBWL investigation focused on the technical state of the engine and the circumstances of the power loss. Investigators examined the Reaction 31's engine, an Octagon 190, and found that the spark plug electrode gap was set to 0.8mm, which deviated from the manufacturer's requirement of approximately 0.5mm. Furthermore, upon inspecting the fuel tank, investigators discovered a 10mm washer loose at the bottom of the tank. This washer was large enough to obstruct the fuel suction inlet.
Findings
- The primary cause of the engine power loss was a reduction in fuel flow caused by the fuel suction inlet being partially blocked by a loose washer moving within the fuel tank.
- An increased spark plug electrode gap contributed to inefficient combustion, further reducing engine performance.
- The pilot's failure to detect the power lines during the emergency landing maneuver led to the collision.