Incident Details
On 30 April 2024, at 18:10 local time (UTC+2), a pilot departed from Szczecin Dąbie Airport (EPSD) in a PZL Mielec M-18B Dromader, registration SP-FFZ, to conduct an aerial agricultural application over a coniferous forest. The flight was performed in visual meteorological conditions (VMC). The start was delayed from approximately 17:00 to 18:10 in anticipation of reduced thermal activity and wind gusts.
During the final working pass over the designated treatment area, flying from north to south at a permissible height of 2–5 meters above an uneven forest canopy (tall trees, young stands, and crops), the right wingtip collided with the top of a tree. According to METAR reports, at the time of the incident (around 19:30), a slight drop in ambient temperature and a decrease in wind speed from 12 knots to 6 knots were recorded compared to earlier in the flight.
The pilot noticed a loss of altitude but, despite a rapid response, could not avoid the collision. He immediately decided to abort the mission and return to the base airport, landing safely at 19:45.
Findings
Post-flight inspection revealed a dent on the right wingtip, which was subsequently replaced with a new one. The pilot, a 66-year-old male, held an Airline Transport Pilot License (ATPL(A)) with a valid Single-Engine Piston (Land) rating and a Flight Instructor (FI(A)) rating. His total flight experience was 13,331 hours, including 1,985 hours in agricultural operations and over 2,100 hours on the M-18B Dromader. His medical certificate was valid until 28 August 2024.
Cause
The accident investigation board determined the cause to be an erroneous assessment of the flight altitude by the pilot, resulting from improper distribution of attention during observation of the forest surface.
Facilitating Factors
A contributing factor was the influence of thermal activity over the sun-heated forest, which disturbed the aircraft's low-level flight. The pilot was aware of the existing meteorological conditions and should have paid greater attention to maintaining a safe altitude, especially since the flight had been postponed due to thermals and the temperature had decreased by only 1°C.
Actions Taken
As preventive measures, the investigating entity reminded all personnel performing agricultural flights over forests to thoroughly analyze terrain materials for the working field and select safe altitudes to ensure collision-free passes. It was also emphasized that any operation of navigation equipment should be conducted during turns, not during working passes over the crop. Additionally, principles of attention distribution and observation of the forest canopy during passes over working fields were discussed.