An engine system for an aircraft capable of operating in a helicopter-type flight mode and a fixed-wing flight mode and is capable of transitioning between those flight modes while in-flight includes first and second engines, and a ducting assembly. The ducting assembly includes a first exhaust subassembly in fluid communication with the first engine and a second exhaust subassembly in fluid communication with the second engine. The first exhaust subassembly permits fluid transfer substantially independent of fluid transfer within the second exhaust subassembly.