What happened
On 29 March 2022, a pilot was conducting a recreational flight involving several landings on various lakes. After departing from the EPLS aerodrome earlier that morning, the pilot had completed several landings and was resting at the shore of Jezioro Lednica. Following a brief refueling from a canister, the pilot continued the flight toward Jezioro Kłeckie.
At approximately 15:20, witnesses observed the N27ZX, an Aventura II ultralight amphibian, approaching from the south at a low altitude. The aircraft performed a right turn at a low altitude, followed by a steep left turn. During the descent phase of this maneuver, the aircraft collided with the surface of the lake. The impact caused the aircraft to overturn and partially submerge; shortly thereafter, the aircraft sank. Emergency responders and divers recovered the pilot from the cockpit, but despite resuscitation efforts, the pilot was pronounced deceased.
The investigation
The PKBWL investigation examined the aircraft's flight history, the meteorological conditions, and the mechanical state of the aircraft. Investigators reviewed CCTV footage from the departure aerodrome and analyzed witness statements regarding the aircraft's behavior during its final maneuvers. The investigation also included an analysis of the aircraft's flight manual (FTS) regarding stall speeds, bank angle limitations, and the effectiveness of control surfaces at low speeds. The wreckage was recovered from the lake, and the engine and control surfaces were inspected for malfunctions.
Findings
- The aircraft was an experimental, amateur-built Aventura II with a valid airworthiness certificate.
- The engine was running until the moment of impact with the water.
- The pilot was operating with a valid license and medical certificate.
- The weather conditions during the flight were conducive to carburetor icing.
- The investigation found that the electric heating for the carburetors was switched off.
- The pilot performed a steep left turn at a low altitude with a bank angle exceeding the permitted 60 degrees.
- The aircraft was likely flying at a speed near its stall limit, making aileron control less effective and increasing the risk of a stall.
- High wind speeds near the aircraft's operational limits likely created turbulence behind terrain obstacles, contributing to an increased bank angle.
- The combination of reduced engine power from icing and the excessive bank angle led to an aircraft stall and spin.