What happened
Following a maintenance period, a positioning flight was completed without incident. However, during the landing roll at the operator's home base, the crew encountered a simultaneous failure of the steering, braking, and thrust reverser systems. As the aircraft type approached the runway threshold, the pilot attempted to use the emergency braking system, but the aircraft failed to stop within the paved surface and eventually came to rest in a ditch. While there were zero fatalities and no injuries among the three occupants, the aircraft sustained significant damage to the fuselage and both wings.
Analysis of the cockpit voice recorder showed that the aircraft traveled for approximately 60 seconds after touchdown. During this period, the pilot made two attempts to engage the thrust reversers. The crew also reported that a third attempt to activate the reversers by the copilot resulted in increased engine thrust, which contributed to the aircraft's acceleration toward the end of the runway.
Findings
Investigation into the mechanical failures revealed that the squat switch assemblies on the left and right landing gear struts had become partially detached from their mounting pads. This detachment caused both switches to be deactivated, rendering the steering, braking, and thrust reverser systems inoperative upon landing. Although the switches were not damaged, the physical state of the assemblies suggested they had been intentionally manipulated during maintenance to set the aircraft to "air mode."
While the brakes and steering functioned during the pre-departure taxi, it is believed that the switches were making intermittent contact at that time. Maintenance records did not show any authorized procedures requiring the disabling of these switches, and the personnel involved denied such actions. Furthermore, the anomaly went undetected during the return-to-service check, the predelivery inspection, and the crew's preflight inspection. Additionally, while the emergency braking system was functional, the pilot did not apply the emergency handle with sufficient force or early enough in the landing roll to prevent the overrun.