How FAEs Work

11 Dec, 2001    ·   660

An abstract from Backgrounder on Russian Fuel Air Explosives ("Vacuum Bombs") at

A typical fuel air explosive device consists of a container of fuel and two separate explosive charges. After the munition is dropped or fired, the first explosive charge bursts open the container at a predetermined height and disperses the fuel in a cloud that mixes with atmospheric oxygen (the size of the cloud varies with the size of the munition). The cloud of fuel flows around objects and into structures. The second charge then detonates the cloud, creating a massive blast wave. (For a demonstration of a FAE explosion, see the U.S. Naval Air Warfare Center Weapons Division, China Lake, California , page at "".) The blast wave destroys unreinforced buildings and equipment and kills and injures personnel. The antipersonnel effect of the blast wave is more severe in foxholes, on personnel with body armor, and in enclosed spaces such as caves, buildings, and bunkers.



Fuel-air explosives were first developed, and used in Vietnam , by the United States . Soviet scientists, however, quickly developed their own FAE weapons, which were reportedly used against China in a 1969 border conflict and in Afghanistan . Since then research and development has continued and currently Russian forces field a wide array of third-generation FAE warheads.



In addition to classic FAE munitions, Soviet scientists have also developed other "enhanced-blast" munitions, particularly reactive-surround and slurry-explosive blast warheads. Both types of warheads work on the same principle by which the explosive is dispersed and mixed with atmospheric oxygen before the detonation process is completed. The destruction, death, and injury are caused by the blast wave. Reactive-surround warheads are thin-walled containers filled with combustible aluminum and nitrocellulose. Slurry-explosive warheads are a mixture of a high explosive or other explosive solid mixed with a combustible liquid.



Blast Injuries



Blast explosives kill or injure in three ways: with the blast wave; with flying debris or by collapsing buildings; and by the blast wind throwing bodies against the ground, equipment, structures, and other stationary objects.



According to a 1993 study by the U.S. Defense Intelligence Agency: 



Bhe [blast] kill mechanism against living targets is unique--and unpleasant.... What kills is the pressure wave, and more importantly, the subsequent rarefaction [vacuum], which ruptures the lungs.… If the fuel deflagrates but does not detonate, victims will be severely burned and will probably also inhale the burning fuel. Since the most common FAE fuels, ethylene oxide and propylene oxide, are highly toxic, undetonated FAE should prove as lethal to personnel caught within the cloud as most chemical agents.1



According to a separate U.S. Central Intelligence Agency study, "the effect of an FAE explosion within confined spaces is immense. Those near the ignition point are obliterated. Those at the fringe are likely to suffer many internal, and thus invisible injuries, including burst eardrums and crushed inner ear organs, severe concussions, ruptured lungs and internal organs, and possibly blindness."2 Another Defense Intelligence Agency document speculates that because the "shock and pressure waves cause minimal damage to brain tissue…it is possible that victims of FAEs are not rendered unconscious by the blast, but instead suffer for several seconds or minutes while they suffocate."3



Lung injuries are particularly difficult to diagnose and treat. If FAEs are used in Chechnya , this would present an additional burden on the ill-equipped and overburdened Chechen hospitals. 






1. Defense Intelligence Agency, "Fuel-Air and Enhanced-Blast Explosive Technology--Foreign," April 1993. Obtained by Human Rights Watch under the U.S. Freedom of Information Act. 



2.Central Intelligence Agency, "Conventional Weapons Producing Chemical-Warfare-Agent-Like Injuries," February 1990. Unclassified document. 



3. Defense Intelligence Agency, "Future Threat to the Soldier System, Volume I; Dismounted Soldier-- Middle East Threat," September 1993, p. 73. Obtained by Human Rights Watch under the U.S. Freedom of Information Act.