A system includes a gas turbine engine having a low speed spool and a high speed spool. The system also includes a spool coupling system configured to mechanically link the low speed spool and the high speed spool. A controller is operable to determine a mode of operation of the gas turbine engine, monitor for a spool coupling activation condition associated with the mode of operation, and activate the spool coupling system based on the controller detecting the spool coupling activation condition. Engagement and power transfer between the low speed spool and the high speed spool occurs based on activation of the spool coupling system and reaching an engagement condition of the spool coupling system.