UA541761-6 & UA541761-7
Engine Series: -4164, -4168, -4168A

The UA541761 and UA541762 series air cooler assemblies are heat exchanger units that are constructed of welded INCONEL 625 components. The air cooler assembly consists of a plate-fin core that contains passages for directing the flow of hot air to be cooled through the core.

The air cooler assembly is an air-to-air heat exchanger used to cool the No. 3 bearing compartment buffer air. Buffer air is bled from the 12th stage bleed manifold and routed to and from the air cooler assembly by external tubing. Low pressure compressor discharge bleed air is used as the coolant. As hot buffer air flows through the air cooler assembly hot air circuit, heat is transferred through the plate-fin core to the low pressure compressor air in the cold air circuit. Cooled buffer air is then routed to the No. 3 bearing compartment. The warmed coolant air is discharged into the fan duct.