The reservoir for the oil system is the center section of the three-section oil tank on the combining transmission. The three-section oil cooler and fan assembly is mounted on the top section of the transmission. Oil is routed from the oil tank through the filter and bypass valve and through an external line to the oil cooler. The oil is then routed by an external line through a check valve to the transmission. In the transmission oil is distributed through internal passages and jets and is sprayed on bearings and gears.
Oil is scavenged from the sump through internal passages by the scavenge clement of the oil pump.
The pump then pumps the oil to the tank. A sight level gage is installed on the forward end of the oil tank. The forward rotary-wing transmission then changes the direction of torque from a horizontal plane to a vertical plane. This reduces the input shaft speed. The oil system serving the forward rotary-wing drive transmission is a complete, separate system.