What happened
Before departing, the pilot received reports of rain and wet road conditions, though no ice was reported at the intended destination. During the final approach to the private airfield, the pilot observed that the runway surface was wet. The crew attempted a standard approach and landing, with the aircraft type touching down at a speed of 110 knots. Following touchdown, the pilot engaged the lift dump and applied the brakes.
Despite these efforts, the aircraft failed to achieve sufficient braking action. In an attempt to regain traction, the pilot maneuvered the aircraft laterally across the runway surface, but the lack of grip persisted. The aircraft subsequently exited the southern end of the 4,370-foot runway, crossed an embankment, and eventually stopped adjacent to a levee. There were no reported mechanical failures or malfunctions prior to the impact with the embankment.
Findings
Calculations performed using the Manufacturer Approved Airplane Flight Manual Supplement indicated that the expected landing distance on a wet runway was roughly 3,400 feet, while an uncontaminated runway would have required approximately 2,800 feet. The determined landing speed (Vref) was approximately 111 knots. At the time of the incident, there was no official report regarding the specific braking action or runway condition for the airfield, as such reporting was not mandatory for this location. The primary factor in the excursion was the inability to achieve braking action on the wet runway surface.