A mid-turbine frame (MTF) assembly having: an outer case circumferentially extending around a central axis; an outer ring secured to the outer case and disposed radially inwardly of the outer case relative to the central axis; an inner case structurally connected to the outer case and disposed radially inwardly of the outer ring relative to the central axis; a main plenum circumferentially extending around the central axis and located between the outer case and the outer ring, the main plenum having an inlet fluidly connectable to a source of cooling air, a first outlet fluidly connected to a secondary plenum between the main plenum and the inner case, a second outlet configured to be fluidly connected to a rotor cavity of the low-pressure turbine, and a third outlet configured to be fluidly connected to a plenum surrounding a containment ring of the low-pressure turbine.