Rocket-propelled grenade
Various warheads are also capable of causing secondary damage to vulnerable systems (especially sights, tracks, rear and roof of turrets) and other unarmored targets.
[2][3][4] The static nature of trench warfare in World War I encouraged the use of shielded defenses, even including personal armor, that were impenetrable by standard rifle ammunition.
[5] This led to the concept of anti-tank guns, a form of artillery specifically designed to destroy armored fighting vehicles, normally from static defensive positions (that is, immobile during a battle).
[7] In order to penetrate armor they fired specialized ammunition from proportionally longer barrels to achieve a higher muzzle velocity than field guns.
[5] As World War II progressed, the appearance of heavier tanks rendered these weapons obsolete and anti-tank guns likewise began firing larger calibre and more effective armor-piercing shells.
[7] Although a number of large caliber guns were developed during the war that were capable of knocking out the most heavily armored tanks, they proved slow to set up and difficult to conceal.
[7] The latter generation of low-recoil anti-tank weapons, which allowed projectiles the size of an artillery shell to be fired from a man's shoulder, was considered a far more viable option for arming infantrymen.
Armies found that they needed to give infantry a human-portable (i.e., can be carried by one soldier) weapon to defeat enemy armor when no wheeled anti-tank guns were available, since anti tank rifles were no longer effective.
Different approaches to this goal would lead to the anti-tank spigot mortar, the recoilless rifle, and, from the development of practical rocketry, the RPG.
Research occasioned by World War II produced such weapons as the American bazooka, British/Allied PIAT and German Panzerfaust, which combined portability with effectiveness against armored vehicles, such as tanks.
An issue that affected the earliest RPG weapon systems such as the German Panzerschreck was that rocket motor propellant could harm the operator.
An RPG is an inexpensive way for an infantryman to safely deliver an explosive payload or warhead over a short distance with reasonable accuracy.
Substantially more expensive guided anti-tank missiles are used at larger distances when accuracy or an overfly top attack are paramount.
For example, if a soldier or other fighter launches an RPG at a hovering helicopter, even if the helicopter releases flares to confuse optical seekers, chaff to confuse radar, or engages in signal jamming, these will have no effect on an in-flight RPG warhead, even though these measures might protect against more sophisticated surface-to-air missiles.
Various warheads are also capable of causing secondary damage to vulnerable systems (especially sights, tracks, rear and roof of turrets) and other soft targets.
In August 2006, in al-Amarah, in Iraq, a Soviet RPG-29 damaged the front underside of a Challenger 2 tank, detonating ERA in the area of the driver's cabin.
Since then, the ERA has been replaced with a Dorchester block and the steel underbelly lined with armor, as part of the 'Streetfighter' upgrade, which was a direct response to this incident.
An early method of disabling shaped charges developed during World War II was to apply thin skirt armor or meshwire at a distance around the hull and turret of the tank.
Today, technologically advanced armies have implemented composite armors such as Chobham armour, which provide superior protection to steel.
One of the first instances the weapon was used by militants was on January 13, 1975, at Orly Airport in France, when Carlos the Jackal, together with another member from the PFLP, used two Soviet RPG-7 grenades to attack an Israeli El Al airliner.
Convoys learned to avoid approaches with overhangs and to send infantrymen forward in hazardous areas to detect the RPG teams.
[30] The most noteworthy use of RPGs against aircraft in Afghanistan occurred on August 6, 2011, when Taliban fighters shot down a U.S. CH-47 Chinook helicopter killing all 38 personnel on board including SEAL Team 6 from a range of 220 m (720 ft).
[31] An earlier anti-aircraft kill by the Taliban occurred during Operation Red Wings, on June 28, 2005, when a Chinook helicopter was destroyed by unguided RPG.
Russian forces had to rely on artillery suppression, good crew gunners and infantry screens to prevent such attacks.
Tank columns were eventually protected by attached self-propelled anti-aircraft guns (ZSU-23-4 Shilka, 9K22 Tunguska) used in the ground role to suppress and destroy Chechen ambushes.
In Afghanistan, the Mujahideen often modified RPGs for use against Soviet helicopters by adding a curved pipe to the rear of the launcher tube, which diverted the backblast, allowing the RPG to be fired upward at aircraft from a prone position.
The Mujahideen also utilized the 4.5-second timer on RPG rounds to make the weapon function as part of a flak battery, using multiple launchers to increase hit probabilities.
At the time, Soviet helicopters countered the threat from RPGs at landing zones by first clearing them with anti-personnel saturation fire.
The Soviets also varied the number of accompanying helicopters (two or three) in an effort to upset Afghan force estimations and preparation.
In response, the Mujahideen prepared dug-in firing positions with top cover, and again, Soviet forces altered their tactics by using air-dropped thermobaric fuel-air bombs on such landing zones.
