The Tube-launched Optically-tracked Wire-guided missiles provide precise, lethal direct fire against main battle tanks, field fortifications, heavy weapons teams, snipers, and fleeting targets of opportunity while minimizing collateral damage. It is the main heavy anti-tank guided missile of the U.S. Army and U.S. Marine Corps, and is used in vehicle and helicopter installations.
The BMG-71B featured extended range. The missile was essentially identical to the BGM-71A except for a longer guidance wire. It was mainly developed for the airborne application, to allow for a greater stand-off range of the helicopters.
The BGM-71C is the result of the Improved TOW program. The missile is more effective against new types of armor by using a copper lined warhead of slightly larger diameter, and also an extendable nose probe fuze. The probe extended after missile launch, and ensured that the warhead detonated at a stand-off distance from the target for optimum efficiency of the shaped charge.
The further improved BGM-71D TOW 2 has an even larger and heavier warhead, which increases the diameter of the warhead section to that of the main missile body. It also has a slightly longer nose probe, an improved double-base rocket motor, and a new countermeasures resistant digital guidance system.
The BGM-71E TOW 2A is designed to defeat tanks equipped with ERA (Explosive Reactive Armor) blocks. It has a small shaped-charge warhead in the nose probe, which explodes the ERA when it is hit, so that the main warhead remains effective against the conventional armor behind the ERA. The BGM-71E also adds ballast to the tail to counter the added weight in the nose probe, and has a timing device to detonate the small primary and large main warheads at the optimum interval.
The main new feature of the BGM-71F TOW 2B is the Overflight Top Attack (OTA) capability. The TOW 2B has a completely redesigned nose section, which includes two downward sequentially fired tantalum EFP (Explosive Formed Projectile) warheads, and an active dual-mode (optical laser/magnetic sensor) fuze. The laser and magnetic fuze work together to detect the height profile and the large metal mass of a tank, detonating the warheads exactly above the target. The guidance system is also updated, flying the missile at a preset height above the operator's line of sight, so that the latter can still point his cross-hairs directly at the target. The BGM-71F does not replace but supplement the BGM-71E.
The TOW 2B Aero is a variant of the TOW 2B, which is a relatively minor modification of existing rounds to extend the range to 4500 meters (14800 feet). The missile has a longer guidance wire and a more aerodynamic nose for enhanced flight performance.
The TOW 2B Aero has been further developed into a wireless missile, which replaces the wire with an RF data link. The RF command transmitter is located in the expendable missile container, and therefore no modifications to the launcher itself are necessary.