What happened
On 23 March 2018, an Ultramagic H-77 balloon, registration EC-GUU, was performing a takeoff from the main square in Vic, Barcelona, as part of the "Mercat del Ram" balloon festival. The balloon was positioned within the enclosed square, which is surrounded by buildings of varying heights.
As the pilot initiated the climb, the basket reached an altitude of approximately 4 meters. At this stage, the wind pushed the balloon toward the north, causing it to drift laterally. Because the balloon had not gained sufficient altitude to clear the surrounding structures, the basket struck the overhang of an upper balcony on building number 2 and subsequently hit the eaves of the roof. During this contact, the envelope slid along the roof and made contact with a chimney, resulting in several tears in the lower panels of the envelope.
Following the impact, the balloon was able to move toward an adjacent, lower building, which allowed it to resume its climb. The flight continued without further incident, eventually landing safely in a field approximately 3.7 kilometers from the takeoff site. There were no injuries to the two occupants.
The investigation
The CIAIAC investigation examined the takeoff procedure, meteorological conditions, and the aircraft's technical state. Investigators reviewed video footage of the takeoff, which revealed that the pilot released the mooring rope when the basket was only about 40 cm off the ground and while the rope was still slack. This prevented the balloon from utilizing its maximum climb speed.
Meteorological data from nearby stations indicated that wind speeds were within the manufacturer's operating limits, though the investigation noted that the enclosed nature of the square created a situation where an apparent loss of lift could occur when the balloon reached higher, faster wind layers outside the building perimeter.
Findings
- The pilot was properly licensed and medically certified, with significant flight experience.
- The aircraft was properly documented and within its maximum takeoff weight.
- The improperly executed takeoff maneuver was the primary cause of the accident; specifically, the pilot released the rope while it was slack and at too low an altitude to ensure a rapid climb.
- The organizers had failed to file the mandatory affidavit of compliance with the National Aviation Safety Agency (AESA) regarding air show requirements.
Safety action
- It is recommended that the manufacturer, Ultramagic, update its Flight Manual to include specific instructions for performing takeoff maneuvers from enclosed spaces in windy conditions.