What happened
On July 22, 2024, at 18:09 local time, an Air Tractor AT-802F Fire Boss, registration S5-BZR, was engaged in aerial firefighting operations near Ilirska Bistrica. The aircraft, operated by the Administration of the Republic of Slovenia for Civil Protection and Disaster Relief (URSZR), had been activated earlier that afternoon to combat spreading wildfires. After successfully performing water drops near Ankaran, the crew encountered a weather front while returning to base.
As the aircraft approached Portorož Airport (LJPZ), heavy rain began to fall, and visibility decreased. The air traffic controller activated runway lights on RWY15 and provided weather updates. During the landing sequence, the aircraft arrived with its landing gear not extended. Consequently, the lower sections of the water tanks made contact with the runway, causing the aircraft to slide approximately 300 meters along the runway toward taxiway B. The pilot was uninjured following the incident, and the aircraft sustained minimal damage.
The investigation
The investigation examined the operational procedures of the operator, the maintenance history of the aircraft, and the prevailing meteorological conditions. Investigators reviewed the pilot's training and experience, noting the pilot was highly experienced with over 3,600 total flying hours. The investigation also scrutinized the regulatory framework governing state-operated aircraft used for firefighting, specifically looking at the oversight responsibilities between different national authorities.
Findings
- The primary cause of the incident was the failure to extend the landing gear prior to touchdown.
- Adverse weather conditions, including heavy rain and reduced visibility, were present during the approach.
- A systemic regulatory gap exists in Slovenian legislation, as there is no clearly defined competent authority for the technical and operational oversight of aerial firefighting operations conducted by state operators.
- The operator's manual did not accurately reflect the actual procedures used during firefighting missions, which were instead following the procedures of a subcontractor.
- The operator's internal safety management system (SMS) lacked sufficient involvement from experienced aviation experts to ensure robust safety oversight.