Shaft power transfer for a multi spool gas turbine engine

A gas turbine engine, comprising:

• a high-pressure shaft drivingly coupled to a high-pressure compressor and a high-pressure turbine;
• a low-pressure shaft drivingly coupled to a low-pressure compressor, a low-pressure turbine, and a fan;
• a first mechanical clutch mechanism operably coupling the high-pressure shaft to the low-pressure shaft, wherein the first mechanical clutch mechanism transfers power from the high-pressure shaft to the low-pressure shaft at a predefined first speed transient condition of the gas turbine engine, wherein the first mechanical clutch mechanism is an overrun clutch;
• and
• a second mechanical clutch mechanism operably coupling the low-pressure shaft to the high-pressure shaft, wherein the second mechanical clutch mechanism transfers power from the low-pressure shaft to the high-pressure shaft at a predefined second speed transient condition, wherein the predefined first speed transient condition is different than the predefined second speed transient condition of the gas turbine engine, and wherein the second mechanical clutch mechanism is an overrun clutch.