What condition poses the highest risk of engine damage when starting a turbine engine?

A hot start condition presents the highest risk of engine damage when starting a turbine engine due to excessive temperatures during the ignition process. In a hot start, the engine does not start correctly, leading to prolonged fuel flow without proper combustion, which can allow the temperature in the combustion section to rise significantly beyond normal operational limits. This can result in overheating of engine components, particularly the turbine blades, potentially leading to structural failure or degradation.

A cold start generally refers to starting an engine at low ambient temperatures, which may present other challenges, such as increased wear during initial operation, but does not pose the immediate risk of excessive temperatures that a hot start does. A flooded engine typically involves excess fuel in the combustion chamber, which can prevent ignition altogether, but it doesn’t lead to the same thermal damage as a hot start. Normal starts are designed to be within safe operational parameters and involve proper engine management to ensure that temperatures remain stable.