In late 2016 Norway successfully tested a software modification in their IRIS-T heat seeking AAMs (air-to-air missiles) so it could successfully hit small, moving surface targets. In this case the target was a small boat. This adds a capability that makes the many IRIS-Ts Norway has competitive with the latest version of the American Sidewinder. In 2015 Norway 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 F-35 takes advantage of new features in Sidewinder, features that the current Norwegian AAM, the IRIS-T didn’t have. A German firm, Diehl, has been providing software and other upgrades for both IRIS-T and Sidewinder to take advantage of the fact that the two missiles are very similar.
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 American Sidewinder 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 2.9 meters (9.8 feet) long, weighs 89 kg (192 pounds), has a 25 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 and the first heat-seeking air-to-air missile. 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.
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.
The JHMCS is standard equipment in the F-35 and that’s another reason for Norway to return to Sidewinder. But the IRIS-Ts are still good, especially if they can be easily updated.