What happens if the High-Pressure Engine-Driven Pump fails?

The failure of the high-pressure engine-driven pump is a critical event in the operation of the Pilatus PC-12 NG's fuel system. When the high-pressure pump fails, it can no longer deliver the necessary fuel at high pressure to the fuel control unit (FCU). The FCU relies on this high-pressure fuel to properly mix with air for combustion in the engine.

Without the high-pressure supply, the engine will not receive the fuel it needs to maintain operation, resulting in a loss of thrust and ultimately leading to engine failure. Therefore, when the high-pressure pump fails, the engine does not continue to operate as normal, nor does the fuel simply bypass to the FCU or result in only low-pressure operations. Instead, the engine would quit due to the insufficient fuel supply necessary for continued operation.