What happened
On June 15, 2004, a Cessna 177 (registration SP-YVD) was performing a corporate flight from Kraków-Pobiednik to Poznań-Ławica, transporting three employees. The flight began without incident, with the pilot rotating at 65 mph and establishing a climb at 80 mph. However, shortly after clearing the tree line at an estimated altitude of 20–30 meters, the aircraft entered a zone of moderate turbulence.
The pilot noted a decrease in the climb gradient while engine RPM remained within the green arc. The aircraft began to sink, and despite the pilot's attempts to pitch the nose down to maintain level flight, the descent continued. During this phase, the pilot observed power lines and buildings ahead. In an attempt to maneuver toward a suitable emergency landing site, the aircraft struck the ground at a slight angle. The impact was followed by a fire that consumed the cabin and the center section of the wings. The pilot sustained spinal injuries, while the three passengers were uninjured.
The investigation
The PKBWL examination focused on the aircraft's technical condition and the weight and balance configuration. Investigators discovered that the engine suffered from significantly reduced compression in cylinder number 2, which had caused a loss of power. Previous unreported incidents of failed takeoffs due to insufficient acceleration were noted.
Furthermore, the investigation analyzed the aircraft's loading. While the pilot's initial weight estimates suggested the aircraft was within limits, a more critical analysis of the passenger masses and baggage suggested the aircraft was operating at a takeoff weight that exceeded the maximum allowable limit by approximately 8.1 kg. The investigation also noted that the pilot had less than 10 hours of experience on this specific aircraft type and had never operated the aircraft at near-maximum weight.
Findings
- The primary cause of the accident was the initiation of the climb in the second speed range, which led to a reduced climb gradient, loss of airspeed, and an eventual stall.
- A significant loss of engine power due to a leak in the second cylinder contributed to the inability to maintain altitude.
- The aircraft was operating at a takeoff weight slightly exceeding its maximum allowable limit.
- The pilot's limited experience on the Cessna 177 type and the presence of moderate turbulence acted as contributing factors.