Sweden's RBS-56 anti-tank missile, or BILL, was designed to defeat composite armor. It uses a HEAT warhead that penetrates tanks from above using Overfly Top Attack (OTA) technology.
The Swedish company Bofors (now Saab Dynamics AB), developed BILL, which stands for Bofors Infantry Light and Lethal) in the late 1970s. The weapon entered service in the mid 1980s.
The RBS-56 is launched by a booster motor. A solid fuel motor sustains the missile's flight to its target. Cruciform fins stabilize the missile as it is in flight.
BILL uses SACLOS guidance. The operator sights the target directly, but the missile flies approximately three feet (one meter) above his line of sight so that it takes a path directly over the target tank.
A proximity fuse detects the vehicle and detonates the HEAT warhead as the warhead passes over the vehicle.
Thus, the charge is concentrated on the top of the tank where the tank's defenses are thinnest.
The warhead is angled down 30 degrees from the missile's path to penetrate the tank's turret roof or engine housing and to avoid explosive reactive armor (ERA) defenses.
BILL can engage targets at a range between 164 and 218 yards (150m to 200m). The missile has a caliber of 5.9 inches (150mm) and is 35.4 inches (900mm) long.
This anti-tank weapon can engage a target in all weather conditions and during nighttime operations
The pre-loaded launch tube and sight unit are attached to a firing post, which can be mounted on a vehicle.
The missile and pre-loaded launch tube together weigh 35.3 pounds (16kg), and the firing post and sight unit have a combined weight of 24.3 pounds (11kg). The missile's average velocity is 656ft/s (200m/s).
A two man crew can deploy the RBS-56 anti-tank missile in about twenty seconds and reload in about seven seconds.
An updated variant of BILL, the RBS-56-2, or BILL 2 was introduced in Sweden in 1999.
BILL is used by Sweden, Austria and Brazil.