The US Navy is hoping to increase the range of the new Raytheon AIM-9X Block III by some 60% over current Sidewinder variants due to the unique needs of the Lockheed Martin F-35 Joint Strike Fighter, the Naval Air Systems Command (NAVAIR) says. The new weapon is scheduled to become operational in 2022.

"The Block III range requirement was in response to Joint Strike Fighter requirements in the 2020+ timeframe," NAVAIR says. "The design is anticipated to increase AIM-9X employment ranges by 60%."

NAVAIR says the current Block II AIM-9X already overlaps some of the range capability of the more powerful Raytheon AIM-120D AMRAAM, however the new Block III variant will increase that overlap. The AIM-9X Block III's increased range will "provide fighter aircraft with increased capacity of BVR [beyond visual range] weapons for tactical flexibility," NAVAIR says.


 Lockheed Martin

The need for that added flexibility arises from the proliferation of advanced digital radio frequency memory (DRFM) jammers that many potential adversaries are adding to their fighter fleets. DRFM jammers have the potential to blind the AMRAAM's onboard radar, which makes the AIM-9X's passive imaging infra-red guidance system a useful alternative means to defeat those threats. While a completely new missile would have been ideal, the Pentagon is faced with era of declining budgets and has to take into account the price tag of any new weapon.

"Programme affordability was a primary concern for new missile development," NAVAIR says. "Modifying the existing AIM-9X for increased range provides a highly affordable solution for meeting the performance requirement."

To create the new AIM-9X Block III, the NAVAIR will primarily focus on the missile's rocket motor. "Increased range will be achieved through a combination of increased rocket motor performance and missile power management," NAVAIR says.

In addition to an improved, more energetic, rocket motor, the enhanced weapon will also have a new insensitive munitions warhead, which will be safer to use onboard an aircraft carrier. However, the Block III will "leverage" the current Block II's guidance unit and electronics-including the missile's AMRAAM-derived datalink.

While the Pentagon needs the new Sidewinder to be a supplemental BVR weapon for situations where friendly fighters are faced with electronic attacks that degrade with radar-guided weapons, it will not compromise on the AIM-9X's close in performance. "The requirement and design call for the same WVR [within visual range]/HOBS [high off-boresight] capabilities as those found in the AIM-9X Block II," NAVAIR says.

The Block III is currently scheduled to enter into its engineering and manufacturing development phase in 2016, NAVAIR says. Subsequently, it will go into developmental testing in 2018 with operational tests starting in 2020. If all goes well, an initial operational capability date is expected in 2022. "The Block III development schedule follows the increased number of Joint Strike Fighter aircraft entering service," NAVAIR says.

Source: Flight International