What happened
On May 31, 2019, at approximately 10:39 LMT, a Midget Mustang VJ1, registration A 44 RFD, was performing a low-altitude flight over an outdoor event near the 303 Squadron Museum in Napoleon, Poland. The aircraft had departed from the Natolin landing field in Kłobucka with the intention of flying to Płock.
During the flight, the pilot executed a climbing turn followed by a dive. While attempting to recover from the dive at a very low altitude, the pilot applied excessive back-pressure on the control column. This maneuver caused a dynamic wing stall, leading the aircraft into a vertical autorotation. The aircraft plummeted into a forest, striking the ground vertically. The impact resulted in the fatal death of the pilot and the total destruction of the aircraft.
The investigation
The PKBWL examination included an analysis of video footage captured by a witness on a mobile phone, which documented the final moments of the flight. The investigation confirmed that the aircraft's control linkages remained intact until impact and that the engine was operational until the moment of collision.
Investigators also examined the aircraft's registration and regulatory status. The aircraft carried the markings A 44 RFD, which were issued by Aero Sport Connection (ASC) under US FAR Part 103 guidelines. However, the investigation found that the aircraft's high wing loading (65 kg/m²) and maximum takeoff mass (408 kg) exceeded the criteria for ultralight vehicles under both FAR Part 103 and FAI microlight classifications. Furthermore, the Polish Civil Aviation Authority (ULC) confirmed that the 'A' prefix registration used by ASC does not correspond to a recognized state of registry in the international code and that the aircraft did not meet the requirements for flying in Polish airspace without specific authorization.
Findings
- The primary cause of the accident was the too aggressive recovery from a dive at low altitude, which induced a wing stall and subsequent vertical autorotation.
- The aerodynamic characteristics of the Midget Mustang VJ1, specifically its high wing loading, contributed to the accident by increasing the minimum flight speed and making the aircraft more susceptible to dynamic stalls and rapid autorotation.
- The aircraft's registration and operational status were inconsistent with Polish and international regulatory requirements for ultralight operations.