UK changes JSF configuration for ASRAAM

The UK has made a significant change to its weapons fit plans for the Lockheed Martin F-35 Lightning II Joint Strike Fighter (JSF).

The original UK intention was to clear four MBDA Advanced Short-Range Air-to-Air Missiles (ASRAAMs) for internal carriage but this has been revised to include two internal and two external weapons instead.

The configuration change was agreed with the JSF Program Office in the United States late last year and was shown in public for the first time during the Singapore Airshow in February. The external ASRAAM fit will be common across all three JSF variants and could therefore attract interest from other international customers, who will otherwise be tied to Raytheon's AIM-9X Sidewinder.

The new ASRAAM plan is a 'work swap' that does away with the requirement to clear the ASRAAM on the F-35's two internal air-to-ground weapon stations. The integration team now has the more straightforward task of providing underwing carriage on stations 1 and 11. The ASRAAM is a rail-launched missile and internal weapons must be carried on a trapeze that swings down clear of the F-35's weapon bay before they can be launched.

It has always been a credo of the JSF programme that external weapons carriage fundamentally compromises the aircraft's very low observable (VLO) design. Speaking at the Singapore Airshow, George Stanridge, Lockheed Martin's vice president of F-35 Business Development, noted that, in general, "if you see something hanging on the aircraft it means you are not a VLO airplane". A new 'stealthy' pylon has been developed for the external ASRAAM and MBDA notes that the finless missile already has a tiny radar cross-section.

Carrying the ASRAAM outside the weapons bay brings several advantages, primarily in allowing passive long-range - beyond-visual-range (BVR) - engagements cued by the missile's seeker or the F-35's infrared search and track sensor.

Image: UK JSFs will now carry two of their four ASRAAM missiles under the wing (R Hewson) 305 of 702 words