What happened
On November 17, 2018, a mid-air collision occurred between two ultralight aircraft during the circuit pattern at the Erkelenz-Kückhoven airfield. The first aircraft, a Remos G3/600, was performing a left-hand turn to enter the final approach for runway 34. Simultaneously, an ATEC Zephyr 2000 C had departed from the same airfield for a local flight.
At approximately 15:30, the two aircraft collided while both were executing a left-hand turn. The impact caused the right wing of the Remos G3/600 to separate from the fuselage. The pilot of the Remos G3/600 successfully deployed the aircraft's emergency parachute system, but the impact with the ground resulted in serious injuries to the pilot. The ATEC Zephyr 2000 C sustained severe damage, including the separation of both wings and a post-crash fire that consumed much of the fuselage. The pilot of the ATEC Zephyr 2000 C sustained fatal injuries.
The investigation
The BFU investigation utilized radar raw data and flight data from a navigation device carried by the Remos G3/600 to reconstruct the flight paths. The analysis confirmed that the Remos G3/600 was in a left-hand turn at the time of the collision. Investigators also examined wreckage from both aircraft, noting that the propeller of the ATEC Zephyr 2000 C had struck the wing strut of the Remos G3/600, and fragments of the ATEC Zephyr 2000 C's wing rib were embedded in the Remos G3/600.
Witness statements were evaluated, including reports of the aircraft flying in the same direction and one aircraft passing under the other. However, the BFU determined that the physical evidence supported a nearly frontal collision while both aircraft were in a left-hand turn. The investigation also considered meteorological conditions, noting that while visibility was generally good, the low angle of the sun created significant glare and reduced visibility for the pilot on approach.
Findings
- The primary cause of the accident was that the approach of the two aircraft went unnoticed by the pilots, leading to the mid-air collision.
- The low sun angle created significant visual impairment for the pilot on final approach.
- The use of a shared arrival and departure route for the circuit pattern increased the density of traffic in a specific area.
- Design-related visibility limitations from within the cockpit of the Remos G3/600 contributed to the difficulty in detecting the other aircraft.
- The small size, low cross-section, and white color scheme of both ultralight aircraft made them difficult to identify visually.
- The lack of an installed collision warning system in either aircraft prevented the pilots from detecting the approaching hazard.