BILL

From the Internet DJ re-produces the specifications and characteristics a light anti-tank missile from SWEDEN

BILL is the Bofors Infantry Light and Lethal anti-tank missile and has the designation RBS 56. The BILL missile system is portable, has day and night capability and can also be mounted onto wheeled or tracked vehicles. It can be transported by air, parachute, helicopter, harnessed to a paratrooper or strapped to a soldier's back.RBS 56 BILL was first demonstrated in 1982 and entered service in the Swedish army in 1988.

DESCRIPTION

The guidance system is guidance-by-wire. BILL works in a top attack mode whereby the missile travels on a trajectory over the top of the target tank just above the turret roof at a height 75cm above the gunner's line of sight. As the missile travels over the top of the tank, the downward canted warhead ignites, is directed at the vulnerable roof of the tank and the jet of the plasticised metal warhead penetrates the tank. The missile is 90 cm in length with body diameter 15 cm. The missile and launch tube weigh 20 kg.

The BILL missile works in top attack mode with the strike angle at 30 degrees to the horizontal, ensuring the shortest route of penetration of the armour, and at least 25% to 50% of the warhead energy is delivered to the interior of the tank.

OPERATION

The set up time is 10 to 15 seconds, and the loading/reloading time is 5 seconds. When the gunner has acquired the target he presses the trigger and keeps the cross hairs on the target until impact. Stearing correction signals are transmitted to the missile by the tethered wire. The SACLOS (semi-automatic command-to-line-of-sight) guidance system incorporates counter countermeasures to provide immunity to jamming. The missile has a backward-directed coded laser beacon. The tracker uses advanced signal processing validity checks. Prediction algorithms on the flight path data make the system resistant to interruptions in the laser beam signal. The system also has resistance to electromagnetic radiation. Signal processing allows the missile tracker to track only its own missile. This feature allows launching of several missiles from closely grouped firing positions.

On firing, a gas generator ejects the missile with a launch velocity of 72 metres per second. A sustainer motor in the missile is ignited and burns for 2 seconds which corresponds to a distance of 400 metres travelled from the launcher. The missile continues its flight ballistically and during the flight a gyrostabiliser controls the roll of the body to keep the warhead in the downward pointing position.

With the missile in the horizontal position, the warhead which is located in the centre of the missile, points forwards and downwards at 30 degrees to the horizontal. The warhead is equipped with a proximity sensor which detects the target and ignites the shaped charge jet at the optimum time. The velocity of the shaped charge jet is higher than 10,000 metres per second, and the shaped charge jet penetrates explosive reactive armour before the reaction takes place. The missile is equipped with a second fuse, an impact fuse, which ignites the warhead in the case of a direct hit rather than in over-fly mode.

DAY SIGHT

The day sight is equipped with a x7 magnification optical assembly. The optical system has cross hairs for target tracking. The sight measures the deviation of the missile's position from the line of sight, and generates the guidance data which is transmitted through the guidance wire to the missile. The day sight has a weight of 5.9 kg complete with protective padding.

NIGHT SIGHT

The night sight is a thermal imager which is easily mounted onto the day sight without any alignment by the operator. The thermal image is reflected into the day sight. The night sight weighs 9.2 kg complete with protective padding. An accessory bag contains four high pressure gas bottles and four batteries. One battery and one gas bottle provide an operational time of 120 minutes.

BILL 2

Bofors have developed a double warhead anti-tank missile, BILL 2, which it is claimed will defeat the add-on protection and the complex main armour of any main battle tank.

BILL 2 travels on an elevated trajectory with an attack altitude 10cm above the target. An advanced sensor recognises the turret or the centre of the target and determines the optimum position for the warheads to ignite. There are two shaped charge jets with time delay and effective angle of compensation. The shaped charge jets strike downwards on a defined spot on the target. The front warhead destroys the reactive armour and then the rear warhead has free passage to penetrate the main body armour of the tank.

The gunner can select firing mode with a four-way switch located on the sight. The modes are:

• Anti-tank mode, with all sensors active, elevated flight path, and algorithms optimised for BILL2 defined threats
• Optional anti-tank/anti-armour mode, with elevated flight path and customer defined algorithms.
• Secondary target mode, with flight path on line-of-sight, sensor system disabled, and impact fuse function.
• Secondary target mode, with optical sensor, delayed ignition, elevated flight path and impact fuse function.

The main enhancements in BILL 2 include:

• Double warhead
• Improved guidance accuracy via the rate gyro which monitors the gunner's tracking movements.
• The addition of a complementary tracking system to provide improved guidance in dirty battlefield conditions.
• The system is compatible with the earlier over-fly top attack (OTA) BILL 1 and is adaptable to new requirements.

The Swedish Defence Materiel Administration, the FMV, has announced that outstanding deliveries of the BILL top attack anti-tank missiles for the Swedish Army will be fulfilled by the BILL 2.