Experts say fighter jets do combat sorties under radar coverage and control of ground staff, and the Gwalior airbase, from where the two planes had taken off, has one of the best monitoring systems. The crash involved a Russian-made Sukhoi Su-30, carrying two pilots, and a French Mirage-2000, flown by one pilot

While an air commodore is investigating the crash of two frontline fighter jets of the Indian Air Force (IAF) during a routine “operational flying training mission“ on January 28, military aviation experts are surprised by the theory of ‘mid-air collision’ doing the rounds. The IAF has not officially commented on this theory.

The crash involved a Russian-made Sukhoi Su-30, carrying two pilots, and a French Mirage-2000, flown by one pilot. Both aircraft had taken off from the Gwalior airbase, about 50 km from where they went down. Apparently, the Mirage 2000 pilot couldn’t get time to react and died in the crash. The Sukhoi pilots ejected to safety near Bharatpur in Rajasthan.

Experts say all fighter jets operate under the complete control of air defence and air traffic controllers. Combat exercises or sorties are carried out not only for IAF pilots but ground staff practice as well. Several questions have come up. How could the two jets come close during a combat sortie? During combat exercises, fighter jets fly under radar coverage and are in active control of ground staff. How then did the ground controller allow them within ‘kissing distance’ of each other? Why did they (ground staff) not intervene to separate the two planes?

While experts are rather surprised by the mid-air collision probability because it was highly unlikely in an era of most advanced radar systems controlling flying, a fighter pilot argued that anything untoward could happen in a fraction of a second midair as fighter jets operate at an average speed of 1,000 kmph (they can fly at speeds up to 2,000 kmph).

Both the Gwalior and Agra airbases of the IAF have upgraded radar systems. Gwalior, being the Tactics and Air Combat Development Establishment (TACDE) base, has one of the best air traffic and air defence radars.

“Pilots of fighter jets remain in communication with one another as well as ground controllers during combat exercises. They receive constant instructions regarding the flight height and speed to be maintained,” said a military officer, on condition of anonymity, adding: “Both the Mirage 2000 and Sukhoi Su-30 have inbuilt safeguards, such as proximity warnings, to avoid collisions. It is next to impossible for jets to come close to each other.”

Some military observers believe the two fighter jets may have gone on individual sorties in separate sectors and somehow came close to each other, and that the air traffic controller and air defence radar failed to spot that. If not a mid-air collision, the coincidence of both aircraft developing technical snags simultaneously and crashing was also “rare”.

Military aviation historians, however, claim mid-air collisions are not that uncommon after all. Since independence, India has lost at least 64 military aircraft and 39 pilots to mid-air collisions. Of these, the Russian-origin MiG-21 has been involved in 11 mid-air collisions—the maximum. “Mid-air collisions are far less frequent now thanks to improved aircraft and technology. It was more common from the 1950s to 1980s,” said a military official.

A court of inquiry is looking into various aspects of the Mirage-Sukhoi crash, including technical issues, judgement error, pilot incapacitation, medical issues and G-lock. G-lock in aerospace physiology refers to loss of consciousness from excessive and sustained G-forces draining blood from the brain, leading to cerebral hypoxia.