In one exemplary embodiment, a gas turbine engine system for cooling engine components includes an engine core, a core housing containing the engine core, an engine core driven fan forward of the core housing, a nacelle surrounding the fan and the core housing, and a bypass duct defined between an outer diameter of the core housing and an inner diameter of the nacelle. Also included is a thermal management system having a coolant circuit including at least one of a first heat exchanger disposed on the inner diameter of the nacelle and a second heat exchanger disposed on a leading edge of a BiFi spanning the bypass duct. The first heat exchanger is in thermal communication with the second heat exchanger.