What happened
On March 22, 2023, an Ultramagic N-425 hot air balloon, registration TC-BVS, was undergoing pre-flight preparations in the Kılıçlar Valley (Region 1) of Göreme, Nevşehir. The aircraft, operated by Pelikan Havacılık Organizasyon Turizm Reklam Taşımacılık ve Ticaret Limited Şirketi, was in the process of transitioning from cold inflation to hot inflation.
As the pilot activated the burner, a gas leak occurred in one of the fuel cylinders, causing the fuel to ignite. The resulting fire caused damage to the balloon's envelope control lines, the basket structure, the burner fuel hose, and several fuel tank protective components. The pilot and ground crews managed to extinguish the fire using onboard fire extinguishers. Because the inflation process was interrupted by the fire, no passengers had yet boarded the aircraft. The pilot sustained one minor injury (second-degree burns) during the emergency response.
The investigation
The UEİM investigation examined the aircraft's maintenance records, the fuel system, and the sequence of events leading to the ignition. The investigation confirmed that the aircraft's maintenance was up to date, all airworthiness directives and service bulletins had been implemented, and the pilot held a valid license and medical certificate.
Technical inspection of the fuel system revealed that while the cylinders themselves showed no physical defects, there was a loosening of the tube connection disconet. The investigation also reviewed the meteorological conditions, noting that the Slot Service Center had issued a "green flag" (permission) for flight operations at the time of the incident.
Findings
- The pilot was properly licensed and medically certified.
- The aircraft was properly registered and maintained according to regulations.
- The aircraft was equipped with necessary fire extinguishers and first aid kits.
- A loosening of the tube connection disconet was identified as a key factor.
- The probable cause was determined to be a material failure resulting from the pilot inadvertently making hard contact with the cylinder connections during the hot inflation process, leading to the gas leak and subsequent ignition.