What happened
On April 10, 2009, a PZL-104 Wilga 35 was conducting training flights at Schmoldow Airfield. The flight crew, consisting of the pilot and a second pilot acting as a safety observer, had been performing several training sorties involving simulated engine failures at an altitude of approximately 2,000 feet.
During the final flight of the session, the pilot announced via radio that an emergency procedure drill was about to be performed. While the aircraft was at an altitude between 35 and 45 meters, witnesses observed the engine noise drop and the aircraft enter a descent. The aircraft subsequently struck the ground approximately 500 meters past the threshold of runway 15, where it underwent a rollover. The impact resulted in two fatalities.
The investigation
The BFU investigation focused on the feasibility of the maneuver and the operational procedures of the flying club. Investigators examined the aircraft's maintenance records, which showed the plane was airworthy and had undergone recent inspections. The investigation also reviewed the pilot's credentials, noting he was a highly experienced glider pilot but had relatively limited experience specifically on the PZL-104 Wilga 35.
Testing conducted by the BFU and Messwerk GmbH in 2013 specifically examined whether simulated engine failures could be safely practiced at such low altitudes in this aircraft type. The investigation also scrutinized the club's internal regulations regarding the use of a "safety pilot," finding that the role's responsibilities and authority were not clearly defined in a way that would have prevented the dangerous maneuver.
Findings
- The primary cause of the accident was the pilot's decision to practice a simulated engine failure at an extremely low altitude, a maneuver that cannot be performed safely in a PZL-104 Wilga 35.
- The presence of the second pilot did not serve as an effective safety resource to intervene or correct the pilot's actions.
- The aircraft's flight manual and the manufacturer's documentation lacked specific instructions regarding the limitations of practicing engine failures at low altitudes or specific control techniques required for such emergencies.
- The club's internal safety procedures for utilizing a safety pilot were insufficiently defined, lacking clear instructions on the pilot's authority or the scope of the training flights.