MAKE ANY FIGHTER AIRCRAFT THE RISKIEST ABODE ON EARTH (PART-1)
Flying fighter aircrafts was never meant for the weak hearted. Ever since 2nd world war when aircrafts became an indispensable component of warfare, the profession of a fighter pilot has been synonymous with thrill, adventure, risk and playing with the fire. Two motives that ensured high degree of advancement in fighter aircraft technology, have been how to kill an opposite aircraft and secondly how to evade that kill. And primary weapons for the kill that have come forth are air-to-air missiles. To evade them man has dabbled with flares, chaff, electronic counter-measures and stealth. Gun has also been in use considerably earlier on, but limitation in its reach and aim means it is out of favour with the pilots these days. Still aircrafts are equipped with guns because there might arise a situation when air-to-air missiles are electronically jammed or waylaid by lasers. Air-to-AIR missiles are broadly classified into two categories – Short range missiles for targets that are within visual range (WVR), and longer range missiles for targets beyond visual range (BVR).
WVR missiles are usually ’heat-seeking’, homing on a target’s Infrared signature- usually from the jet exhaust. Sometimes leading edges of the wings of a supersonic jet also get hot enough to invite a short-range missile. Earlier infrared-homing missiles could be targeted only when you were directly behind the enemy aircraft. Now the seekers of these missiles have improved to such a level that you can practically aim them from any angle. These missiles can track even dimmer sources such as fuselage and are known as “all-aspect” missiles. Besides, modern heat-seeking missiles make use of imaging infrared (IIR) where the IR sensor is a focal-plane array which is able to produce an image in infra-red, much like the CCD in a digital camera. The combination of IIR sensors and advanced processing makes these missiles more accurate and harder to evade using decoys like flares and chaff. That’s not all. Together with proximity fuses, these capabilities ensure the missile attacks the most vulnerable part of the aircraft such as cockpit. Otherwise earlier, many aircrafts would at the most get a hit on the exhaust pipe and limp to safety.
Most modern short-range air-to-air missiles such as AIM-9X Sidewinder and ASRAAM, Chinese PL-10 and Israeli Python-5 now use IIR seekers, though the Russian R-73 still relies on a simple infrared (IR) seeker.
Missiles can now be cued and locked on using helmet-mounted sighting (HMS) systems, meaning that the pilot does not have to manoeuvre to place himself right behind his target. In pilots’ jargon terms like ‘tail chase’ and target being ‘dead ahead’ were quite common. But now a Helmet Mounted Display (HMD) provides pilot with increased situational awareness, an enhanced image of the scene, and he can fire at targets far off his ‘boresight’ by simly pointing his head in that direction. Moreover, in good old times the air crafts would move rapidly across a missile’s line of flight, duck, swivel or fly criss-cross to defeat the missile, because it could not turn instantly. But now it has become much harder to defeat them as many modern Short Range Air-to-Air Missiles feature thrust-vectoring rocket motors, giving them a huge improvement in maneuverability. Now let me discuss some of the most lethal WVR missiles and point out their salient features that make them a nightmare to any pilot flying any modern aircraft.
AIM-9X SIDEWINDER :
The AIM-9X is the latest member of the AIM-9 SIDEWINDER family. It has a distinctly different aerodynamic configuration compared to earlier variants, which relied on moving canard foreplanes and rollerons on the tail fins for control. The AIM-9X has smaller fixed forward fins and cropped tailfins that lack rollerons, and in their place has moving paddles that give direction to the thrust of the rocket motor. The smaller fins reduce atmospheric drag and enable internal carriage by the F-22 RAPTOR and the F-35 Joint Strike Fighter.
The AIM-9X uses the same Raytheon-developed IIR seeker as the MBDA AIM-132 ASRAAM, which is capable of lock-on before or after launch to a target that is in its field of regard said to be up to be 90° off boresight. In other words it has 180° field of view and a useful lock-on-after-launch capability, while the weapon is well integrated with the JHMCS (Joint Helmet Mounted Cueing System). With a cherished lineage that has undergone a large number of test-firings, AIM-9X Sidewinder has come of age and been produced in massive numbers for the US forces. A Block II (X-2) version, with improvements to the fuze and other components, entered service in 2009. Though Block III development has stalled, the US is developing two future short-range weapons – the small advanced capabilities missile (SACM) and the miniature self-defence munition (MSDM).
Diehl Defence’s IRIS-T was designed to counter the Russian R-73 ARCHER, and to be very agile. The missile is compatible with SIDEWINDER launchers and targeting systems, but featured a new, lower drag aerodynamic configuration with exceptionally broad-chord wings and relatively small tailfins. Like the AIM-9X, it features thrust vectoring, but also embodies Ku-band fuzing (the AIM-9X uses a laser fuze). The IRIS-T uses a two-colour scanning seeker similar to that used on the MBDA MICA IR weapon. BGT claims that scanning arrays are less susceptible to directed IR countermeasures (DIRCM) than staring arrays.
On 14 June, Diehl Defence signed another contract for the supply of short range air-air missiles IRIS-T (InfraRed Imaging System – Tail/Thrust Vector Controlled) to Thailand, continuing the successful cooperation of recent years.
As early as 2011, the Royal Thai Air Force (RTAF) had selected the European short-range missile for arming their GRIPEN and F-16 fighters. In addition, the new procurement plans to integrate the missile into the F-5 fleet.
With its exceptional performance features, IRIS-T is one of the world´s most advanced short-range air-to-air missiles. In addition to defeat enemy fighter aircraft, self defence capability against attacking air-to-air or ground-to-air missiles is provided. Even attacks from the rear can successfully be defeated without having to change course. IRIS-T was developed and procured by Germany, Greece, Italy, Norway, Spain and Sweden as successor of the aging SIDEWINDER missiles. The series production started in 2005. Other user states today include Austria, Saudi Arabia, South Africa and, case in point, Thailand. As a multi-purpose weapon, IRIS-T is also used as a surface-to-air missile in a ground-based air defence role.
The MBDA AIM-132 ASRAAM
It was designed to a different philosophy compared with the AIM-9X and IRIS-T, with marginally less agility at very close range but with lower drag and a significantly longer range (giving a significant beyond-visual range capability) and a much larger ‘no-escape zone’. ASRAAM was the first SRAAM with an advanced IIR seeker head – a seeker subsequently adopted for the AIM-9X.
MBDA’s MICA is a similarly long-range weapon, and is unique among Western missiles, being available in both IR- and radar-guided variants (the MICA IR and MICA RF). It was also the first Western air-to-air missile to use thrust vectoring and the first operational missile to demonstrate an over-the-shoulder shot.
Rafael’s PYTHON 5
It is the latest variant in the Israeli short-range AAM family and features a dual-band (IR and ultra-violet) seeker head. It uses a conventional SIDEWINDER-like configuration, albeit with fixed canards in front of the moving control fins, and swept tail fins. Though it lacks thrust vectoring, Rafael claims that the missile is as agile as any missile that embodies the feature.
Japan’s Mitsubishi AAM-5 uses a similar configuration to the IRIS-T and MICA, and features a gimballed IR focal plane array multi-element seeker. The missile is used by JASDF F-15J and F-2 fighters. An upgraded version, the AAM-5B, offers longer range and increased resistance to infra-red countermeasures.
The V-3E A-DARTER
It is developed by Denel Dynamics (formerly Kentron) and Mectron, Avibras and Opto Eletrônica, is a virtually smokeless thrust-vectoring SRAAM, which can be cued via a helmet sight, and that has lock on after launch and over the shoulder capabilities. Some have claimed superiority over the IRIS-T in some key respects.
The MAA-1B PIRANHA