A TEJAS light fighter seen equipped with the Derby system at the National Flight Test Centre

IDN has learnt from reliable sources that as part of its scheduled weapon trials, preparations are underway to test the Beyond Visual Range DERBY missiles this week at Jamnagar proving grounds. These weapon trials are part of the Final Operational Clearance (FOC) mandate which is likely to be completed by end July this year.

Continuing with its successful stride of production and flight trails in 2017, India's Tejas light fighter achieved a major milestone in February 2016. One of the limited series production (LSP) platforms fired a DERBY Beyond Visual Range Air-to-Air Missile (BVRAAM) missile for the first time.

A Fighter Jet sports the Derby Missile

However, during the tests it was noted that the exercise did not yield the expected results as the DERBY missile caused excessive vibrations to the Tejas structure. As per detailed analysis by ADA the problem was found to be caused due to an inherent flaw with the missile and had got nothing to do with the Tejas. However, IDN also learnt that the problems have been sorted out and the Tejas test platform has been tweaked appropriately to accommodate and fire the missiles.

A mock-up of Naval Tejas shown with Derby and Python 5 Missiles at Aero India 2015

Rafael had delivered 100 Python-5 missiles to India however, it is learnt that IAF has abandoned the project (for undisclosed reasons) to equip Indian fighter jets with these missiles.

The Israeli DERBY series of missiles are one of the most advanced AAM systems in the world. The DERBY Beyond-Visual-Range (BVR) Air-To-Air Missile, is a medium-range (~50 km) active-radar seeker missile. Though technically not part of the "Python" family, the missile is basically an enlarged PYTHON-4 with an active-radar seeker. The DERBY BVR missile includes ECCM features. Like the PYTHON short range air-to-air missile, the DERBY has the same canards (wings), warhead, rocket motor design and proximity fuse and a dramatic increase in range. It's launch weight is 118 kg with a range of 63 km.

Notably, the IAF has procured the DERBY BVR-AAM over the indigenous ASTRA BVRAAM to expedite the induction of TEJAS into its arsenal. The DERBY BVRAAM missile is a tried and tested weapon. The DERBY has a range of 50 km, compared with 80 km of the ASTRA missile. 

Only a handful of missile builders -- in the US, Russia, Europe and China -- have mastered the technologies that go into air-to-air missiles. In September 2017 the defence ministry had formally announced the successful development of the most challenging missile India has developed so far -- the ASTRA. Fired from a fighter aircraft travelling at over 1,000 km an hour, the ASTRA destroys an enemy fighter 65 to 70 km away. The trials conducted off the Odisha coast on September 11 to 14 saw seven ASTRA missiles being fired from a Sukhoi-30MKI (captive flight trials for avionics integration as a part of the test was also successfully conducted) at pilotless aircraft that were designated as targets. All seven ASTRA missiles hit their targets.

The ASTRA is fired from the Russian Vympel launcher -- a rail under a fighter aircraft's wing from which the missile hangs. The Vympel launcher is integrated with all four of India's current generation fighters -- the Su-30MKI, MiG-29, Mirage 2000 and the Tejas -- enabling the ASTRA to be fired from all of them.

In a significant advancement in the quest for indigenisation, two of the seven Astra missiles tested had undergone a crucial modification. The very heart of their ability to hunt down aircraft in the air, their seeker, had been replaced. The existing Russian Agat 9B1103M active radar seeker used on the Astra had been replaced with an Indian Ku-band seeker developed by the DRDO’s Research Centre Imarat (RCI) in Hyderabad.

Sukhoi Su-30MKI firing the air-to-air ASTRA missile during weapons trials
Indian engineers have already integrated & tested the previous generation of DERBY missiles on the Tejas Mk-1 jet, which was demonstrated for the first time in the Iron fist 2016 Exercise where it demonstrated its swing role capabilities while engaging ground based target and switch to fire BVR missile in same mission simultaneously. This was a significant achievement in ensuring engagement of hostile intrusions in the beyond visual range combat scenarios, it is also worthy to note that only a select few have this aggregated capability.

It should be noted that TEJAS has already completed the weapons trails of the Russian R-73 missile.

Our Bureau