Raytheon details AIM-9X Block II+ missile
Raytheon Missile Systems (RMS) has disclosed details of the planned evolutionary upgrade of its AIM-9X Sidewinder Block II variant short-range infrared guided air-to-air missile: the AIM-9X Block II+.
In February 2016, the US Department of Defense (DoD) fiscal year (FY) President's Budget Submission (PB17) documents noted that for "FY 2017, the programme will continue to produce the AIM-9X Block II All Up Round [AUR] and the AIM-9X Block II Captive Air Training Missile [CATM]. To meet survivability requirements inherent to the fifth generation aircraft platform programmes, the Department of the Navy will introduce a third variant of the [AIM-9X Block II] missile labelled AIM-9X Block II Plus (Block II+).
AIM-9X is a joint US Navy (USN) and US Air Force programme, led by the USN. In June 2011, the DoD's Milestone Decision Authority (MDA) established the AIM-9X Block II missile programme with approval for Low Rate Initial Production (LRIP). The Acquisition Program Baseline for AIM-9X Block II was signed in December 2011, and the Block I programme was terminated. Block II completed operational test and evaluation in early 2015, with the navy declaring an Initial Operational Capability at the end of March 2015; approval to transition into Full Rate Production (FRP) was signed off by the DoD's Assistant Secretary of the Navy for Research, Development and Acquisition (ASN[RDA]) in August 2015.
The Block II missile incorporates a newly designed onboard processor, a new battery, an electronic ignition safe/arm device, and the new DSU-41/B Active Optical Target Detector (AOTD) fuze/datalink assembly (replacing the DSU-37/B laser proximity fuze in the Block I). A one-way datalink (aircraft to weapon) - the same as that employed on the AIM-120D AMRAAM - provides for enhanced range, and improved effectiveness throughout the engagement zone. An associated missile software upgrade - Operational Flight Software (OFS) 9.3 standard - introduces additional functionality for trajectory management (for improved range), datalinking with the launch aircraft, improved lock-on-after-launch, target re-acquisition and improved fuzing.
In January 2016, the US Naval Air Systems Command (NAVAIR) awarded Raytheon Missile Systems a USD8.3 million contract modification for the procurement and installation of hardware required to update five prototype Block II+ Captive Test Missiles (CTMs) into a production representative hardware configuration. The contract also provided for the procurement of 40 Propulsion Steering Section hardware sets required to convert AIM-9X Block II CTMs into AIM-9X Block II+ CTMs and AIM-9X Block II Special Air Test Missiles (NATMs) into AIM-9X Block II+ NATMs
Mark Justus, AIM-9X programme director at RMS told IHS Jane's that the Block II+ initiative comprises "minor hardware modifications to the external missile body which improve aerodynamics and [launch] platform survivability".
Justus said that for the Block II+, the missile's five main components - the guidance unit, AOTD, warhead, rocket motor, control actuator system, and internal circuitry - remain the same as Block II. "Software versions for AIM-9X are driven by the main processor unit [MPU]. Block II and II+ use the same MPU with identical software versions and associated capability," Justus added.
Justus said that Block II+ is interchangeable with a Block II missile "at any time and on any platform. As with Block II, the Block II+ will remain backward compatible with a Block I AIM-9X. Visually, the differences between a Block II and II+ are small, and difficult to discern, and the mass properties are identical."
PB17 notes that "in FY 2017 the [Block II+] missile will incorporate the obsolescence redesign of the control actuator system battery. Beginning in FY 2019, the missile will incorporate tech refresh of critical obsolete components required to ensure producability. Specific hardware updates will include the inertial measurement unit, and the dome and the guidance processor. The guidance unit is the critical component to ensure continued production of the missile system and avoid production gaps."
PB17 continues, "Unlike the PB16 submission which assumed a full cut-in of Block II+ production in FY 2017, this budget procures both the Block II and Block II+ variants as a cost savings measure in FY 2017 and beyond. While the Block II+ is critical to mission success in certain mission areas, the balance of the AIM-9X inventory will be produced as regular Block II missiles to meet Naval Munitions Requirement Process [NMRP] demands."
"The production line is currently only building Block II missiles. We expect to fold in Block II+ production as part of next year's [FY 2017/Lot 17] contract," Justus noted.
The Block II+ improvement effectively replaces, at least for the foreseeable future, the proposed AIM-9X Block III development, which was cancelled in PB16.
Scheduled to have become operational in 2022, the AIM-9X Block III concept provided for 60% greater range - driven by the proliferation of advanced digital radio frequency memory jammers that a number of potential adversaries are adding to their fighter fleets.
The plan was to retain the Block II guidance unit and fuze components in keeping with Raytheon's evolutionary approach to missile improvements, Justus noted. "The Block III effort was focused on back-end improvements - enhancing the kinematic range of the missile with an improved rocket motor as well as folding in the US government requirement for an insensitive munition (IM) certification, while maintaining the original mass properties specification to avoid unnecessary flight testing for carriage and safe separation certifications.
While AIM-9X Block III was cancelled, funding for several of the Block III planned improvements, including increased lethality, enhanced infrared countermeasures, and improved IM performance, has been moved to the AIM-9X Block II programme, as part of the System Improvement Program III (SIP III). A USD312 million contract for this effort was awarded in September 2015.