What happened
On December 13, 2023, at approximately 20:30 UTC, a tethered hot air balloon, registration PP-XVG, was participating in a promotional event in Brasnorte, Mato Grosso. The flight was intended to celebrate the Christmas season and was sponsored by a local credit union. The balloon was operating as a captive flight, secured to the ground by anchor lines at heights between 20 and 50 meters.
During the operation, a strong wind gust caused the anchor line to rupture. The RVB-N77 balloon drifted uncontrollably for approximately 500 meters, colliding with electrical power lines, a cellular antenna, and several residential buildings. During the sequence of impacts, the pilot and the passenger—who was dressed as Santa Claus for the promotion—were thrown from the basket. The collision with the antenna caused the envelope to tear, leading to a loss of altitude and a final impact on houses in the Renascer neighborhood. The aircraft sustained substantial damage, and both occupants sustained serious injuries.
The investigation
The investigation by SERIPA VI was initiated two months after the event following a notification from the Mato Grosso Public Prosecutor's Office. Due to this delay, investigators were unable to examine critical physical evidence, such as the condition of the anchor lines, the weight of the balloon at the time of the accident, or the state of the burners and gas cylinders.
Investigators focused on meteorological data from official sources, including REDEMET and CPTEC. The analysis revealed that the area was experiencing an unstable atmosphere characterized by convective clouds, moderate to severe turbulence, and wind shear. While the crew had recognized the approaching storm and attempted to deflate the balloon to abort the flight, subsequent strong gusts caused the tether to fail before the procedure could be completed.
Furthermore, the investigation identified significant regulatory discrepancies. The pilot lacked a valid license from the National Civil Aviation Agency (ANAC), although they held a valid medical certificate. Additionally, the aircraft was operating under an Experimental Flight Authorization (CAVE) that specifically prohibited passenger transport for promotional or commercial purposes, as well as any activities categorized as specialized aerial services.
Findings
- Adverse meteorological conditions involving wind gusts and atmospheric instability.
- Impaired decision-making process regarding the timing of the flight cancellation.
- Operational non-compliance, including the use of an unauthorized pilot and conducting a promotional flight in violation of the aircraft's experimental flight restrictions.