What happened
On July 8, 2023, a Z-37A aircraft, registration OK-HJK, was performing agricultural spraying operations near the village of Velké Opatovice. The pilot was tasked with the biological protection of a cornfield, flying from Chrudim airport (LKCHOR).
After performing an initial reconnaissance of the area, the pilot began the working flight passes. During a westward pass at an altitude of approximately 8 meters, the aircraft struck high-voltage power lines. The impact caused the wires to snap and fall to the ground, resulting in a localized power outage. Despite the damage, the pilot found the aircraft still controllable and elected to return to LKCHOR, landing safely shortly after the incident.
Following the impact, the aircraft sustained significant damage to the rudder, the upper right wing, and the propeller blade. There were no injuries to the pilot.
The investigation
The ÚZPLN investigation examined the pilot's statements, aircraft documentation, and the physical site of the accident. The investigation noted discrepancies between the pilot's testimony and the visual evidence regarding the number and direction of the flight passes performed.
Investigators also reviewed the operator's Standard Operating Procedures (SOP). The SOP requires that reconnaissance flights be conducted at a minimum altitude of 50 meters to identify obstacles. The investigation found that the pilot's reconnaissance was insufficient and did not comply with these established procedures.
Findings
- The pilot had limited experience in agricultural flight operations, with only 7 hours of flight time specifically dedicated to this type of work.
- The pilot performed an inadequate reconnaissance of the field and its surroundings, primarily observing only the high-voltage lines along the southern boundary.
- The pilot failed to identify the perpendicular high-voltage lines that crossed the working area.
- The pilot's flight path during the working phase was inconsistent with the intended area and the organization's SOPs.
- Insufficient reconnaissance of the terrain and obstacles was the primary cause of the accident.