What phenomenon occurs if the high-pressure engine driven pump fails?

If the high-pressure engine-driven pump fails, the engine will lose power and eventually fail. This pump is crucial for supplying the necessary fuel at the correct pressure for combustion in the engine. If it malfunctions, the engine may not receive enough fuel to maintain its operational performance. This lack of fuel pressure leads to a reduced power output, and if the situation is not corrected promptly (for example, if a backup system is not available or operational), the engine will eventually stall or fail completely.

The other options do not accurately reflect the implications of a high-pressure pump failure. While the engine may cool down as fuel flow diminishes, this is more a consequence rather than a direct phenomenon. The engine continuing to operate is not viable due to the dependency on the pump for proper fuel pressure. Lastly, while there may be backup systems in some aircraft, the question focuses specifically on the scenario where the high-pressure engine-driven pump fails without indicating an automatic switch to a backup, making that choice not applicable in this context.