What happened
On July 23, 2014, at approximately 15:50 LMT, a Twister gyrocopter, registration A21MMS, crashed into the sea near the fishing harbor in Jarosławiec, Poland. The aircraft had departed from a meadow in Jezierzanach for a routine flight along the coastline. During the flight, the aircraft encountered turbulent atmospheric conditions. The pilot attempted a maneuver that resulted in the loss of control, leading to the destruction of the rotor head assembly. The impact with the water was so violent that the seatbelts were torn, and the pilot was ejected from the cabin, likely coming into contact with the engine's propeller before death. The aircraft was completely destroyed.
The investigation
The PKBWL investigation focused on the technical state of the aircraft and the pilot's actions. Investigators established that the Twister was an experimental aircraft whose certification process had not been completed, meaning it had not undergone required ground or flight testing. The investigation also examined the pilot's experience and the lack of essential documentation, such as a Flight Manual or Maintenance Manual. Furthermore, the commission looked into the unauthorized modifications made to the rotor head brake and the pilot's lack of radio communication with Air Traffic Services while operating within an active controlled zone.
Findings
- The primary cause of the accident was the pilot's loss of control during flight in turbulent weather, which triggered the destruction of the rotor head.
- The aircraft's certification process was unfinished, leaving its performance limitations unverified.
- There was a critical absence of an Operating Manual and a Maintenance Manual, leaving the pilot unaware of specific operational limitations.
- The pilot may have performed an unusual maneuver intended to impress onlookers.
- The pilot's analysis of the weather conditions was incomplete, failing to account for the complexities of the coastal terrain and turbulence.
- Unauthorized modifications to the rotor head components contributed to the structural failure during the event.