A series of cameras on the outside of the stealth warplane feed high-resolution images into the helmet, including infra-red images at night, which are then projected on to the inside of the pilot's visor. Special sensors inside the cockpit track the movement of the helmet, so that when the pilot turns his head his view of the skies or ground outside changes accordingly.
When he looks down he sees not his own feet on the cockpit floor but the ground below, slipping past at hundreds of miles per hour. On-board computers also feed in essential flight and combat data on to the display, as well as superimposing target symbols to locate enemy and friendly aircraft or ground targets, even if they are too far away to see with the naked eye.
A Ministry of Defence spokesman said: "The computerised symbology will be displayed directly on to the pilot's visors, providing the pilot with cues for flying, navigatingand fighting the aircraft. It even will superimpose infra-red imagery on to the visor to allow the pilot to look through the cockpit floor at night and see the world below - like something out of Terminator." Link