MAKE ANY FIGHTER AIRCRAFT THE RISKIEST ABODE ON EARTH
In part-1 we discussed the WVR missiles. Though weapons like the ASRAAM and MICA MICA a significant long range reach, they were never intended to be primarily for BVR use.
Early BVR missiles were beam-riders, or used semi-active radar homing (SARH). These kinds of weapon required the launch aircraft to keep the target illuminated throughout the missile’s flight time and limited it to supporting a single missile in flight. This meant keeping the fighter’s radar pointed at the target, limiting the launch aircraft’s ability to manoeuvre, resulting in closure in a head on engagement, and increasing the risk of a return missile shot.
The next generation of BVR missiles tended to have an active radar for terminal homing, and a notional ‘fire and forget’ capability using inertial mid-course guidance. A launch aircraft could also launch and support several missiles simultaneously. But, in reality, the target might well not be where it was predicted to be when the missile was launched and the missile’s active radar, scanning a small cone of sky, might not find it. Therefore, these missiles tend to require mid-course updates from the launch aircraft, updating the target position, and only becoming truly autonomous when the missile’s onboard radar locks on to the target.
The AIM-120 AMRAAM
The AIM-120 AMRAAM entered service in 1991, and dominated BVR air combat for the next two decades. The AMRAAM has been progressively updated, resulting in a succession of improved variants, including the AIM-120C with smaller clipped fins to allow internal carriage by the USAF F-22 RAPTOR, the AIM-120C-6 with an improved fuse and the AIM-120C-7 with improved homing and longer range.
The AIM-120D is the latest, further upgraded version of the AMRAAM, featuring 50% greater range than the already-extended range AIM-120C-7 and an inertial navigation system (INS) augmented with embedded GPS. The missile also incorporates a new datalink. The AIM-120D still relies on a mechanically-scanned X-band active radar seeker, though this has been improved and has a better ability to detect off-boresight targets. With a range of about 160km – details are classified – the AIM-120D has a longer reach and better kill probability than previous AMRAAMs, but may not be a match for the rival MBDA METEOR. More seriously, some worry that it may be grossly outranged by new Chinese and Russian air-to-air weapons, and a replacement is being sought.
The Next Generation Missile (formerly the Joint Dual Role Air Dominance Missile – JDRADM), was a proposed AMRAAM and AGM-88 HARM replacement cancelled in 2013. A parallel project, the T-3 (Triple Target Terminator) programme, continued aiming to produce a weapon for use against enemy aircraft, cruise missiles and air defence networks. More recently, funding for a new Long Range Engagement Weapon has been allocated as part of an ‘emerging capabilities technology development’ effort.
The MBDA METEOR was designed to meet a multi-national European requirement for a next generation BVR missile with superior range and kinematic performance to the American AIM-120.
METEOR uses a solid fuel, variable flow rocket that can be throttled back to save fuel for the final attack phase, giving more energy to maneuver during the endgame. This gives the METEOR a much larger no-escape zone and a greater ability to chase and defeat a maneuvering target.
METEOR is able to get mid-course guidance updates not just from the launch aircraft, but from third party aircraft such as other fighters, or airborne early warning and control (AEW&C) platforms. The pilot of the launch aircraft may never have to use his own radar, firing on the basis of targeting information provided by third parties.
Rafael’s DERBY entered service in 1998 and is broadly equivalent to the initial AIM-120A. The upgraded I-DERBY ER missile was unveiled at the Paris Air Show 2015 and features a solid-state active radar seeker and a dual-pulse rocket motor, giving an operational range of up to 100 kilometres. The status of an air-to-air version of the STUNNER surface-to-air missile, which features a dual mode seeker in a unique ‘dolphin’ nose, is uncertain.
India’s ASTRA Mk.1
India’s ASTRA Mk.1 is in limited series production and has been integrated with the Indian Air Force’s Sukhoi Su-30MKI fighters. MIRAGE 2000 and MiG-29 integration is expected to follow. The Defence Research & Development Organisation (DRDO) plans to develop a Mk 2 version with longer range and a larger engagement envelope.
Russia’s primary BVRAAMs are the R-27 (AA-10 ALAMO) and R-77 (AA-12 ADDER, sometimes dubbed AMRAAMSki). The R-27 is available in IR-guided and SARH versions, and there are extended range variants of both. They allow aircraft like the Su-27 and MiG-29 to fire pairs of IR- and SARH missiles to maximise kill probability. The newer R-77 has active radar homing and is broadly equivalent to AMRAAM.
The R-33 (AA-9 AMOS) and R-37 (AA-X-13/AA-13 ARROW) are long-range air-to-air missiles (with ranges of 160km and 300km respectively) carried by the MiG-31 FOXHOUND, and of similar configuration to the US AIM-54 PHOENIX, as used by the F-14 TOMCAT.
Russian development programmes include the Novator KS-172, a very long-range weapon primarily intended to engage US AEW, ISR and tanker aircraft far behind the front line. The KS-172 is believed to form the basis of the Indian K100 missile.
China’s most advanced in-service BVRAAM is the PL-12, which is broadly comparable to the AIM-120C4. It is believed to use a derivative of the Russian Agat 9B-1348E seeker, as used in the R-77. The PL-15 is a redesigned variant with cropped aerosurfaces to allow it to fit into the internal weapons bays of the J-20 and J-31. Development programmes include the PL-X – a very large, very long-range missile seen carried by a J-11B during the 2016 Red Sword exercise, and believed to be intended as an AWACs killer.