 The rotodome uses bleed air, outside cooling doors, and fluorocarbon based cold plate cooling to maintain the electronic and mechanical equipment temperatures.The hydraulically rotated antenna system permits the Westinghouse Corporation's and AN/APY-2 passive electronically scanned array radar system to provide surveillance from the Earth's surface up into the stratosphere, over land or water.Other major subsystems in the E-3 Sentry are navigation, communications, and computers.