June 19, 2015: Norway has ordered 200 AIM-9X Block II Sidewinder air-to-air missiles for its 56 American F-16 fighters. These missiles will cost $1.73 million each with accessories and tech support. The Norwegian F-16s entered service in the early 1980s and are wearing out. Norway plans to buy 30-40 F-35s to replace the F-16s.

The Norwegian F-16s were initially armed with Sidewinders but after 2005 were replaced with locally developed (by a European consortium) IRIS-T. The German Air Force was the first to receive the IRIS-T air-to-air missile, back in late 2005. The IRIS-T is very similar to the U.S. Sidewinder heat seeking missile, but was developed and built, with European components, in Europe. The IRIS-T can be used by any aircraft that can use Sidewinder. The IRIS was in development since the 1980s, with the U.S. as one of the original partners. But that arrangement fell apart when the Cold War ended in 1991, and it wasn't until 1995 that the project was revived. The first test launch of IRIS-T took place in 2000, with mass production starting five years later. The IRIS-T is 9.8 feet long, weighs 192 pounds, has a 12 kilometer range and is very maneuverable. Its rocket motor generates very little smoke. Most European nations were expected to use the IRIS-T from then on instead of the Sidewinder. There are orders and deliveries for over 5,000 IRIS-Ts so far. But improvements in the Sidewinder and other competitors has cut into IRIS-T sales, as has happened in Norway.

The AIM-9X-2 is the latest version of the Sidewinder, a missile that has come a long way since it first appeared in the 1950s. The 9X-2 can lock-on-after-launch. That is, the missile can be fired and then directed to a target via a datalink. That means it can be fired at ground targets or at an enemy aircraft behind you. The X-2 version also makes improvements in the warhead fuze and other components. As impressive as all these features, most are already found in similar missiles made in several other countries (including Russia and China). In effect, the X-2 version is just keeping up. What the U.S. sells, in addition, is an impressive track record of reliability and actually performing as expected in combat. Over 6,000 X model Sidewinders have been built or ordered since it entered service in 2003. Block II (X-2) entered service in 2009.

The AIM-9 is a heat seeking missile and the heat sensors have become much more sensitive since the first AIM-9s. The current versions of the missile work by detecting a heat source at the point where the pilot is looking. This is done using the JHMCS (Joint Helmet Mounted Cueing Systems), which allows a pilot to see, displayed on his visor, critical flight and navigation information. Sort of like a see-through computer monitor or HUD (Head Up Display). Most importantly, the pilot can turn his head towards a target, get an enemy aircraft or ground target into the crosshairs displayed on the visor, and fire a missile that will promptly go after the target the pilot was looking at. For Sidewinder the pilot has to be looking at something giving off enough heat to catch the attention of the missile's heat sensor. With the X-2 the pilot can launch the missile before he has located the target via the JHMCS, saving a critical few seconds.