What happened
On April 30, 2024, an M-18B Dromader, registration SP-FFZ, departed from Szczecin Dąbie Airport (EPSD) at approximately 18:10 local time to perform agricultural spraying operations over a coniferous forest. The flight was delayed from its original 17:00 departure time to wait for a reduction in thermal turbulence and wind gusts.
During the final working pass, flying from north to south at an altitude of approximately 2 to 5 meters, the right wingtip of the aircraft struck the top of a tree. The pilot noticed a drop in altitude but was unable to prevent the collision despite a rapid reaction. Following the impact, the pilot immediately decided to abort the mission and returned to the base airport, landing safely at 19:45. A post-flight inspection revealed dents on the right wingtip, which required the component to be replaced.
The investigation
The PKBWL examined the flight parameters, meteorological conditions, and the pilot's operational procedures. The investigation noted that the flight was conducted under Visual Meteorological Conditions (VMC). Meteorological data indicated a slight decrease in temperature and wind speed during the period of the incident. The investigation also reviewed the pilot's experience, noting the pilot was highly experienced with over 13,000 total flight hours and 2,100 hours specifically on the M-18B Dromader.
Findings
- The primary cause of the incident was the pilot's incorrect assessment of the aircraft's flight altitude due to improper distribution of attention while observing the forest surface.
- Thermal turbulence caused by the sun-heated forest acted as a contributing factor, disturbing the aircraft's altitude during low-level flight.
- It was noted that the pilot may have been monitoring parameters on the AG-NAV navigation device during the working pass rather than during turns, which is a deviation from safe practice.
Safety action
- Personnel performing agricultural spraying operations have been instructed to more thoroughly analyze terrain data to ensure safe flight altitudes that prevent collisions.
- It has been reinforced that the operation of navigation equipment should only be performed during aircraft turns, not during active working passes over the target area.
- Procedures regarding the distribution of attention and forest canopy observation during spraying passes have been reviewed.