The tendency of MiG aircraft to come crashing down - right from the time it became the backbone of the Indian Air Force over four decades ago - earned the fighter jet epithets such as "flying coffin" and "widow-maker".

On Wednesday, figures divulged by defence minister A.K. Antony in Parliament reinforced in numerical terms how the ageing Soviet-era fleet had shockingly been on a wing and a prayer for such a long period but still not grounded.

The Rajya Sabha was informed that over the past 40 years, India had lost more than half of its MiG combat fleet of 872 aircraft. The minister disclosed that "482 MiG aircraft accidents took place till April 19, 2012".

Antony also revealed that these crashes led to the loss of precious lives of 171 pilots, 39 civilians and eight persons from other services. The minister went on to state that the cause of the accidents were "both human error and technical defects".

The revelation in Parliament was damning enough to evoke an immediate response from experts. "The Indian Air Force has lost several talented pilots, senior and junior, thanks to the flying coffin that the MiGs are. It is very easy for officers on the ground conducting inquiries to blame pilots and the human element after each crash. But each IAF pilot puts his life at stake from day one," a retired Wing Commander from Pune said.

Drawing a comparison with Pakistan, which is not exactly in the pink of health financially, another IAF officer said the neighbouring country does not have such a high incidence of young fighter pilots losing their lives as they have been flying more sophisticated fighter jets for years now. "Each time a MiG goes down, people talk of millions and billions of rupees getting lost, but there is no value for a pilot's life," the officer observed.

Notwithstanding such overwhelming evidence against its frontline fleet, the IAF was of the view that not much should be read into the numbers because MiGs were the only aircraft flown for most of the time. It also asserted that "serious efforts" had gone into bringing the crash rate considerably down.

Former vice chief of air staff Pranab Kumar Barbora said that while it was a fact that the IAF has lost many MiGs and quite a few pilots, the rate of accidents in the context of the number of flying hours had been reduced substantially. Air Marshal Barbora, who had flown a MiG-21 just before he retired in 2010, maintained that it was a fantastic aircraft even as its high landing speed (around 340 kmph for some variants) made it slightly tricky to handle. He said no aircraft was offered for flying in the IAF without any kind of serviceability.

Air Marshal (retd) T.S. Randhawa, who was the director general of inspection and safety, said the IAF dealt with accidents with utmost seriousness and a concerted all-round effort was being made to ensure that the crash rate came down. "The number of accidents doesn't tell the real story," he said.

It, however, indicates the problem of shortage of aircraft. The IAF's fighter fleet strength currently stands at 34 squadrons. According to the force's calculations, the number will further dip to 31 in the coming years and it would not reach the desired levels of 42 squadrons before 2027.

This is essentially owing to delays in getting replacements for ageing planes. The parliamentary standing committee took note of these shortages in its recent report, highlighting the fact that the MiG fleet was "overstretched".

The first MiG was bought by the country in 1966. Since then, the IAF has been flying various variants of the fighter jet. Different versions of the MiG-21 are still in service out of which the T-69/69B (trainer), T-75 (BIS) and (Bison), T-77 (Badal) and T-96 (Trishul) have been flying for more than 40 years.

While the IAF has grounded the MiG-23MF, MiG-23BN and MiG-25, the MiG-27 and 29 have still got more than 25 years of life.

The air force has already begun phasing out MiG-21s in batches and they would be out of service by the end of the decade. The MiG-27s will be phased out next and the MiG-29s are being upgraded. All these aircraft are stationed at frontline bases across the country - from Hashimara in the east to Jodhpur and Jaisalmer in the west.

The MiG-21 is a particularly difficult aircraft to manoeuvre because of its high-speed landing and restricted runway visibility owing to the canopy design. Since it is a single-engine aircraft, bird-hits tend to affect it more. Environmental factors peculiar to Indian conditions, too, impact the aircraft.

"As a senior pilot, I have trained several juniors on the MiGs and we have faced problems. But in keeping with the unwritten code of the armed forces, we could never point out shortcomings in the aircraft," the retired Wing Commander said.

"It is an established fact that several young IAF pilots lost their lives because they were not willing to eject despite engine flameouts. Nobody ever cares about these factors as the super bosses have their own point to prove - that MiGs are very safe and airworthy," another officer pointed out sarcastically.

It is difficult to calculate the cost of the entire MiG fleet since various versions of the jet have been bought over a period of 40 years. The latest variant, called Bison, is estimated to be worth Rs20 crore. The IAF has over 100 operational Bisons. Furthermore, the cost of upgrade of the MiG-29s alone will amount be around US $940 million.