What happened
On July 26, 2008, a Piper PA-28R-201, registration OH-PEA, was engaged in a private VFR flight near Halli, Finland. The pilot, flying without a pre-planned route, decided to fly at a very low altitude over Lake Päijänne to observe local landmarks and acquaintances' properties.
While flying at an altitude of approximately 10 meters (33 feet) above the water near Paunulahti, the aircraft struck a 2-meter-wide gap in the landscape containing a 20kV three-conductor power line. The pilot reported seeing something brown just before the impact, which he initially mistook for a bird. The collision severed all three 14mm conductors and caused significant damage to the aircraft, including a deep cut in the left wing leading edge that punctured the fuel tank, a hole in the left windshield, and damage to the propeller and cockpit roof antenna.
Despite the damage and fuel leak, the pilot maintained control of the aircraft and successfully performed an emergency landing on runway 26 at Halli airport.
The investigation
The Finnish Safety Investigation Authority (OTKES) examined the aircraft's condition, the pilot's physiological state, and the environmental factors. Investigators found that the aircraft was airworthy and the pilot held a valid private pilot license. The investigation also reviewed the pilot's flight preparation, noting that no flight plan or GPS route had been programmed for the flight. Witnesses on the shore observed the aircraft flying at an exceptionally low altitude and noted the high speed of the approach.
Findings
- The pilot was not fit for flight due to insufficient sleep, having only rested for 1–2 hours prior to the flight.
- The pilot made imprudent decisions driven by impulse, including the decision to fly at an extremely low altitude.
- The pilot's attention was diverted by scanning the shoreline for landmarks, leading to a failure to detect the power lines.
- The power lines, which were positioned at a low height of approximately 10–15 meters, were not marked on aeronautical charts.
- The primary cause of the damage was the collision with the power lines during low-level maneuvering.