Aircraft Collides With Hidden Rut During Grass Field Landing (N8164B)

What happened

The aircraft was operating on an unprepared grass field located off the airport when it collided with an unseen rut during the landing phase. The pilot had previously made a low pass over the same field, visually inspecting the area and observing no obstacles. Based on this inspection, the pilot determined that it was safe to proceed with the landing.

However, upon touchdown, the nose gear struck a hole concealed by the grass. This impact caused the nose gear to collapse, resulting in the aircraft nosing over. The weather conditions at the time were visual meteorological conditions (VMC). No flight plan had been filed for this operation.

The investigation

The investigation focused on the physical evidence of the collision and the circumstances surrounding the landing site selection. Key findings included:

• The presence of a rut or hole in the unprepared grass field that was not visible during the prior low pass.
• The collapse of the nose gear due to the impact with this hidden obstacle.
• The lack of a filed flight plan, indicating an unregulated operation.
• The weather conditions were confirmed to be VMC, suggesting visibility was not the primary limiting factor for the initial inspection.