Control system for a gas turbine engine

A method for preventing a gas turbine engine restart in response to a severe mechanical failure, the method comprising:

• determining a rate of change of a first process condition, a rate of change of a second process condition, and a third process condition;
• determining a potential severe mechanical failure of the gas turbine engine based on at least two of the following:
• the rate of change of the first process condition exceeding a first failure threshold, the rate of change of the second process condition exceeding a second failure threshold, or the third process condition, or a rate of change of the third process condition, exceeding a third failure threshold;
• confirming the potential severe mechanical failure of the gas turbine engine, wherein confirming the potential severe mechanical failure of the gas turbine engine comprises determining both an accommodation time period following the determined potential severe mechanical failure has not elapsed and determining the gas turbine engine is operating in sub-idle conditions within the accommodation time period, wherein determining the gas turbine engine is operating in sub-idle conditions within the accommodation time period comprises determining the gas turbine engine has reached sub-idle conditions within the accommodation time period;
• and
• preventing an engine restart based at least in part on determining the gas turbine engine is operating in sub-idle conditions.

A control system for preventing a gas turbine engine restart in response to a severe mechanical failure, the system comprising one or more processors and one or more memory devices included with the gas turbine engine, the one or more memory devices storing instructions that when executed by the one or more processors cause the one or more processors to perform operations, the operations comprising:

• determining a rate of change of a first process condition exceeds a first failure threshold, the first failure threshold indicative of a severe mechanical failure of the gas turbine engine;
• determining a potential severe mechanical failure of the gas turbine engine based at least in part on the determined rate of change of the first process condition exceeding the first failure threshold;
• confirming the potential severe mechanical failure of the gas turbine engine by determining both an accommodation time period following the determined potential severe mechanical failure has not elapsed and determining the gas turbine engine is operating in sub-idle conditions within the accommodation time period, wherein determining the gas turbine engine is operating in sub-idle conditions within the accommodation time period comprises determining the gas turbine engine has reached sub-idle conditions within the accommodation time period;
• and
• preventing an engine restart based at least in part on determining the gas turbine engine is operating in sub-idle conditions.