April 30, 2012: Israel has developed an APS (Active Protection System) for helicopters, to protect against RPG and similar unguided rockets. Israeli military helicopters already have anti-missile systems that detect incoming heat seeking missiles and use a laser to blind the heat sensor in the missile. An APS fires a small missile or a group of small projectiles to destroy incoming missiles or unguided rockets.
All existing APS were designed to protect ground vehicles. Most APS consist of radar to detect incoming missiles. A complete system weighs about a ton. For helicopters the system has to be a lot lighter (less than 200 kg/440 pounds) and use only rockets. Israel's current ground APS, Trophy, cannot be used because it fires off multiple projectiles, some of which might hit the helicopter's rotor. The helicopter APS, called Fliker, uses small missiles, and it was recently tested and successfully stopped an RPG rocket. More testing and refining of the system is required before it can be used in a combat zone. That would most likely be Gaza, where Hamas is amassing an arsenal of anti-aircraft weapons. But while the missile defense systems can take care of heat seeking missiles, there is still danger from the increasing number of unguided rockets (mainly RPGs) fired at low flying Israeli helicopters.
APS has been around for a long time but it only recently began to catch on. Russia pioneered the development of the APS anti-missile systems. The first one, the Drozd, entered active service in 1983, mainly for defense against American ATGMs. These the Russians feared a great deal, as American troops had a lot of them, and the Russians knew these missiles (like TOW) worked. Russia went on to improve their APS systems but was never able to export many of them. This was largely because these systems were expensive (over $100,000 per vehicle), no one trusted Russian hi-tech that much and new tanks, like the American M-1, were seen as a bigger threat than ATGMs.
Meanwhile, Israel was the first country to develop an APS that worked in combat. Last year the Israeli Trophy APS destroyed incoming RPG rockets and guided missiles. All this came a year after first equipping Merkava tanks with APS. Trophy, like Fliker, operates automatically, and the crew doesn't realize the missile or RPG rocket has been stopped until afterwards. That, however, is how APS is supposed to work.
This first combat use is a big deal because APS has been around for nearly three decades but demand, and sales, has been slow. The main purpose of APS is to stop ATGMs, but on less heavily armored vehicles stopping RPG type warheads is important as well. The Israeli Trophy APS uses better, more reliable, and more expensive technology than the original Russian Drozd (or its successors, like Arena) APS. For about $300,000 per system Trophy will protect a vehicle from ATGMs (Anti-Tank Guided Missiles) as well as RPGs (which are much more common in combat zones). Israel is the first Western nation to have a lot of their tanks shot up by modern ATGMs and apparently fears the situation will only get worse.