What happened
On 4 September 2018, a Zlín Z-526 F, registration OK-DRK, was performing a familiarization flight at Brno Tuřany airport (LKTB) with two occupants on board. Following a standard flight profile, the pilot received clearance to land on the grass runway 26.
During the approach, the pilot began executing landing checklists. While attempting to extend the undercarriage, the pilot instead operated the master electrical switch, which is located immediately adjacent to the landing gear control switch on the instrument panel. Because the pilot simultaneously extended the flaps, the resulting change in aircraft pitch and slight deceleration led the pilot to believe the gear had successfully deployed. The pilot failed to verify the gear position via the cockpit's light or mechanical indicators.
Upon realizing the gear was still retracted, the pilot was too low to execute a go-around. The aircraft touched down on the grass runway with the undercarriage retracted. The engine stopped abruptly as the propeller struck the ground. The aircraft came to a stop after traveling approximately 70 meters. There were no injuries to the crew or the passenger.
The investigation
The ÚZPLN investigation examined the cockpit configuration, the pilot's actions, and the aircraft's maintenance history. The investigation established that the landing gear control switch and the master electrical switch are both two-position switches of a similar type, located in close proximity on the left side of the panel. While the gear switch is protected by a plexiglass cover, the investigation noted that the pilot's rapid execution of checklists contributed to the error. The investigation also confirmed that the aircraft was airworthy and that all maintenance was performed according to manufacturer requirements.
Findings
- The primary cause of the accident was a pilot error involving the confusion of the master electrical switch with the landing gear control switch.
- The pilot did not follow the established checklist methodology to verify the gear position via visual light or mechanical indicators.
- The simultaneous extension of flaps created a physical sensation (deceleration and pitch change) that reinforced the pilot's false belief that the gear had been deployed.
- The aircraft sustained damage to the propeller, engine cowling, cooling air intake, and both flaps.