The United States and France are seeking to equip their jets with the British Brimstone missiles used so successfully in Libya over the last two months. Originally developed as an upgraded version of the American Hellfire, Brimstone ended up as a Hellfire in general shape only. Weighing the same as the Hellfire (48.5 kg/107 pounds), Brimstone was designed to be fired by fighter-bombers, not just (as with Hellfire) from helicopters and UAVs. Aircraft can carry more of these lightweight missiles. These are perfect for small targets, including vehicles, that need to be hit, without causing injuries to nearby civilians or friendly troops.
Three years ago, Britain added a dual-mode (radar and laser) seeker to its Brimstone missiles. Originally, Brimstone was to be just an American Hellfire with a British seeker (a miniature, millimeter wave, radar) and configured to be launched from jets. Brimstone did that, but never got a chance to show how effective it was until Afghanistan and Libya. The performance of Brimstone was particularly impressive, and that got the Americans and French interested in using it as a highly effective anti-vehicle weapon for fast-movers (jet fighter-bombers).
Hellfire was first developed three decades ago as an helicopter launched anti-tank weapon, but has proved to be very useful against enemy infantry hiding out in buildings or caves. Hellfire later proved to be an ideal weapon for use by larger UAVs. The current version has a range of eight kilometers, while Brimstone has a range of 12 kilometers.
The Brimstone radar seeker makes it easier to use the missile in "fire and forget" mode. The laser seeker is more accurate (to within a meter or two of the aim point.) When used on jet fighters, like the Tornado, there is a special launcher that holds three Brimstone missiles (instead of one larger missile). The launcher hangs from one of the Tornado hardpoints. This launcher will also be used on the new Eurofighter. The nine kilogram (20 pound) warhead is sufficient to destroy vehicles, without causing a lot of casualties to nearby civilians. British fighter pilots have become quite good at coming in low and taking out individual vehicles with Brimstone missiles. Carrying a dozen or more Brimstones, a fighter-bomber can easily use all of them in one sortie, all the while staying out of range of ground fire.
So successful has Brimstone been in Libya, that the Royal Air Force is running out of them. There's no immediate shortage, but if the Libya operation goes on for months, new missiles will have to be ordered in order to maintain war reserve stocks (large quantities needed to support intense action at the start of a war.)