Low level strike

MiG-21 fighter base in Tezpur, Assam..1979. I was scheduled for a practice low-level strike mission as the wing-man in a two-aircraft mission. I was Blue2 in Blue formation.

To get over the hassles of routing and timings and commercial traffic disruptions at other airfields, specially civilian airfields, practice missions like these take off from their airfield; carry out a triangular navigation exercise and mock-strike one's own airfield.

We were to simulate attacking an enemy airfield with a Reinforced Cement Concrete runway using Durandal concrete-buster bombs, render the runway unusable and get away. We also had to ensure that we stayed below the vision of early-warning radar, which meant we had to fly at 100 metres above the ground or less.

As the wing-man, I planned the navigation sortie, which took us in a wide arc over the Brahmaputra and the Kaziranga National Park, northwards crossing the Brahmaputra once again, towards the Nameri National Park before turning left, crossing the Kameng River and aligning with the runway for an attack along Runway 23. It was monsoon season and one of those rare days that allowed low-level flying. The Brahmaputra was swollen and its banks were up to 60 kms apart - flying over the river was like flying over the sea.

After a briefing by my formation leader Blue1, we proceeded to our respective aircraft. Our navigation plan had been filed with Air Traffic Control, including our Estimated Time on Target (ETT).

ETT is almost a fetish with fighter pilots and during air exercises, penalty points are allotted for ETTs beyond +/-4 seconds. So to hit a target at a designated time, one has to work backwards from ETT to navigation time to take-off-roll time, to throttle opening time, to taxi-ing time, to engine starting time to strap-up time. As everything was very finely timed, with a small margin added, we strapped up in our cockpits, closed the canopy and armed the canopy and ejection seat explosive cartridges, started engines and taxied out to Runway 05.

We had ATC clearance for take-off, so we lined up on either half of the runway for a formation takeoff - two fighter aircraft taking off together, using half the runway each. Blue1 called out "Reheat" over the radio telephone and both of us lit up our afterburners, the kick in the seat of the pants telling us it had lit-up, holding the aircraft, straining against brakes. "Wheels roll NOW" and we both released brakes, reset our chronometers and begin rolling down the runway. Blue1 keeps his afterburner at partial setting so that Blue2 has a small power-band to play within, for keeping station. The acceleration is exhilarating! At 200 kph the Air Speed Indicator (ASI) begins to register. Keep station. Speed at middle marker OK. Keep station. 360 kph. Unstick. We're airborne. Wheels up. Climb to 500 m, turn Southwards and set course to first checkpoint. Carry out cockpit checks and descend to 100m above the ground.

The barometric altimeter can no longer give us reliable readings. At such close quarters to the ground you cannot trust a pressure device. We have set our radio altimeter alarm at 50m and engaged the auto-pilot recovery mode - if the aircraft descends below 50m the auto pilot will, quite violently, pull up the aircraft above that.

We're at 900 kph now, 100m above the ground, flying in a loose tactical formation, separated from each other by 100 metres. 900 kph is a great speed to fly at, because mental calculation of distances is so easy with a whole number of 15 km/min or 4 secs to a km. The navigation route, drawn on a paper map, with checkpoint timings, is visible on my right thigh, inserted in a talc pocket sewed on to the right thigh of my flying overalls. But both of us have memorised every checkpoint timing to the second. We reach our first checkpoint on time and turn left Northwards towards our next checkpoint. Inside the turn Blue1 points out a herd of rhinos. Oh yes, "contact!", I call out. As we roll out of the turn, I check my chronometer - yes, the turn was perfect, our timing is perfect to the second.

The only navigation equipment practically available to a MiG-21 pilot in those days was the Eyeball Mk-I; no GPS, no Variable Omni Range (VOR), no Instrument Landing System (ILS). There was an Automatic Direction Finder (ADF) which would tell you the direction to a ground based radio beacon. You knew sine and cosine values for all angles in 15 degree increments by rote, so that your angle to a beacon, your chronometer and your Air Speed Indicator (ASI) could allow you to calculate mentally your distance to a beacon. But during operations all beacons would be switched off, especially in enemy territory! There was a good primary compass too, but a compass is a pretty useless piece of equipment if you don't know where you are in the first place!

At our next checkpoint we turn left over the Kameng River, and hope we are aligned with the runway, still more than 30 km away, eyes straining to check the first sight of the runway so that we can carry out last second manoeuvres to align with the runway. Blue1 will carry out a Durandal bomb run on the left of the runway. I will bomb the right side. We are now in tighter formation, with me about 50 m behind and half a runway width to the right of Blue1. A quick look at the chronometer. We're bang on time. "Runway contact" I call out. "Contact" responds Blue1. We make a quick correction in alignment. We're less than 10 km from target, approaching it at 900 kph! A few seconds more.

The runway is approaching us at a weird perspective at level flight, 100m above the ground, instead of the 8 degree glide slope one is used to while approaching it for landing. Centre... centre... the thumb slides slowly to the bomb release button on the joystick, calmly pushing aside the safety guard. Oxygen flow has increased to both pilots. Heartbeats are in the range of 180 bpm, blood pressure shooting up to above 180/120 mm Hg. We're over the runway when suddenly "BOGEY 12 o'clock!"

In millisecond time frames, two super-tuned human bodies threw two high performance jet fighters into an extremely violent, rivet-popping climbing turn to left and right, away from the runway centre-line, saving themselves and an Indian Airlines Fokker Friendship and all its passengers from sudden death!

An obvious ATC error, clearing the IA plane to take-off while a low-level strike was coming in, had almost killed two fighter pilots and a few dozen other people. Blue1 and Blue2 climbed and regrouped, joined circuit and landed.

We never did learn whether the Indian Airlines pilot even saw what almost happened! We only know, like us, he didn't file a near-miss report. Our fighters, having exceeded g-tolerance limits, were taken off the fleet for detailed air-frame checks. The errant air traffic control officer drove down to the Squadron tea-room and hugged us both tight – that was apology enough. Otherwise, it was just another day...

(Rajiv Tyagi is an erstwhile IAF MiG-21 fighter pilot)