The U.S. Air Force has released some details on the next version of the AIM-120 AMRAAM medium-range air-to-air missile, the AIM-120D (or "phase 4 version"). Raytheon started work on the missile in 2003 and initial deliveries are expected in 2007. 

AMRAAM-D will incorporate a two-way datalink, as well as GPS guidance for the missiles navigation, This will make the missile more accurate. The new datalink will enable the missile to report its status once launched and will likely report back some sort of summary data from its onboard radar, such as distance from target once it has locked on. It will allow the missile to engage in attacks at targets to the side or rear of the aircraft., outside of a fighters normal front-directional radar coverage. A fighter armed with the AMRAAM-D could launch on targets that are behind it such as an enemy fighter trying to line up for a tail shot. The two-way datalink would also be used to improve such tactics as launching the missile at a distant target identified by an AWACS radar plane, using the missiles own onboard radar to lock onto targets. A two-way data link would give fighters the option to use the AMRAAMs radar data to update their own tactical displays. 

AMRAAM is 12 feet long, 7 inches in diameter, and a littler larger than 17 inches across with its wings. Weighing at 356 pounds, it has a range of more than 37 kilometers. It is currently in service with the U.S. Air Force, Navy, and 25 countries around the globe. Doug Mohney