What happened
On July 16, 2011, a Tecnam P9SB Echo, registration OK-EUU36, was conducting a flight from LKCS with the intention of visiting the Lipno and Šumava areas. During the flight, the pilot performed several low-altitude maneuvers, frequently descending below the minimum regulatory altitude over the water and terrain.
While flying near Nová Pec, the aircraft struck 22 kV electrical power lines spanning the water at a height of approximately 18.5 to 21.3 meters. The impact severed a middle conductor and destroyed the aircraft's propeller. Following the strike, the aircraft continued for about 320 meters before impacting a tree and obstacles in a residential garden. The impact triggered a fire that consumed the aircraft. Although the crew activated the ballistic parachute system, the deployment occurred too late to prevent the crash. The pilot and passenger both sustained fatal injuries, passing away in the days following the accident.
The investigation
The ÚZPLN investigation examined the aircraft's flight path, the condition of the power lines, and the pilot's maneuvers. Witnesses observed the aircraft flying extremely low over the water, at times so low that the propeller spray disturbed the surface. Investigators found that the impact with the wires caused a sudden loss of engine power due to propeller destruction and subsequent engine vibration, which also led to fuel vapor contamination and the subsequent fire. The investigation also noted that the aircraft was likely overweight at the time of takeoff.
Findings
- The primary cause of the accident was the collision with 22 kV electrical power lines while the pilot was flying below the minimum required altitude.
- The pilot was performing maneuvers that were inconsistent with the declared training flight profile.
- The low altitude made it extremely difficult to identify the power lines, which were partially obscured by trees and lacked warning markings.
- The activation of the ballistic parachute system occurred too late to prevent the impact with ground obstacles.