Gas turbine engines and methods for reducing spool thrust in a turbine section thereof

A method, comprising:

• detecting a loss of oil event to a thrust bearing assembly of a gas turbine engine during operation of the gas turbine engine, wherein the gas turbine engine includes a turbine disk, a shaft coupled to the turbine disk, and a turbine disk inner cavity downstream of the turbine disk, wherein the thrust bearing assembly is configured to mitigate axial loads on the shaft during operation of the gas turbine engine;
• and
• in response to detecting the loss of oil event:
• actuating, by a controller having one or more processors, a back-pressuring seal assembly to move a seal land of the back-pressuring seal assembly toward a downstream face of the turbine disk such that the seal land forms a continuous axial seal about the turbine disk inner cavity;
• supplying a pressurized gas to the turbine disk inner cavity to increase a gas pressure in the turbine disk inner cavity to an extent greater than an operating gas pressure of the turbine disk inner cavity;
• and
• maintaining the continuous axial seal and the gas pressure within the turbine disk inner cavity while the gas turbine engine is operating and thereby reduce the axial loads on the shaft.