What happened
On August 18, 2011, an agricultural aircraft, a PZL Mielec M-18A, was conducting operations to spread magnesium lime in the forests of the Erzgebirge region. Due to noise complaints, the operator had recently moved takeoff and landing operations to an external grass strip located approximately one kilometer west of Neudorf.
Following a midday break, the pilot attempted a takeoff at 13:10 local time. During the takeoff roll, the pilot noticed that the aircraft was accelerating more slowly than usual. In response, the pilot activated the emergency jettison mechanism for the spreading equipment while still on the ground. Despite the reduction in weight, the aircraft failed to clear obstacles and collided with trees located approximately 100 meters beyond the end of the runway. The impact caused light damage to the aircraft and damage to the trees.
Following the incident, the pilot performed a visual inspection and subsequently transferred the aircraft to Kyritz (EDBK) for repairs.
The investigation
The BFU investigation examined the aircraft's configuration, the takeoff performance, and the characteristics of the airfield. The investigation confirmed that the aircraft was operating at a high takeoff mass of 4,633 kg, which was near its maximum allowable takeoff weight of 4,700 kg. The load included approximately 1,550 kg of spreading material.
The investigation also surveyed the takeoff strip, which was a grass surface with a 170-degree heading. While the initial part of the runway had a slight upward gradient, the subsequent section featured a downward slope of approximately 6%. The investigation noted that the aircraft's right wing, fuselage underside, and ailerons sustained damage during the collision with the trees.
Findings
- The aircraft was operating at a near-maximum takeoff weight.
- The pilot experienced a lack of expected acceleration during the takeoff roll.
- The takeoff was performed from an improvised grass strip with varying gradients, including a significant downward slope following the initial climb.
- The pilot attempted to mitigate the performance issue by jettisoning the spreading load during the takeoff roll.