The Apache is a twin-engine, heavily armed ground-attack helicopter built for armed reconnaissance, precision strike and close air support. Its role is to find and destroy armour and hardened targets ahead of friendly troops, and to support them once contact is made - which is why the crew is split between a pilot and a dedicated co-pilot gunner. The AH-64E variant, the Apache Guardian, adds an integrated infrared laser for easier target designation and imagery that blends infrared with night vision, along with the sensor processing that lets a crew track and rank a large number of targets at once. It can engage tanks, vehicles, troop concentrations and communications and logistics nodes, and can defend itself against other helicopters with Stinger missiles.