There have been nine 'incidents' at different Indian airports in the last three months-most of them caused by a combination of heavy rain and short runways- the same two factors that are suspected to have caused the Tam Airbus A-320 to crash in Sao Paulo on Tuesday, killing around 200 people.

Even veteran pilots get the monsoon jitters. At the best of times, flying in heavy rain, with transverse winds and heavy cloud cover is nerve-wracking. But operating in these conditions on a runway smaller than 9,000 feet can really drive up the blood pressure, not least because, in classical aviation terms, it's unsafe.

The runways on most of India's 200-plus airports are short of the 9000-foot safety benchmark. During most times, it does not really matter. But it is during extraordinary conditions that the length of the landing strip can make all the difference.

When the margin for error is small, aircraft can easily overshoot a short, slippery stretch of tarmac. In the latest of the nine incidents this year, just over two weeks ago, a Jet Airways plane descended at Indore's Devi Ahilyabai Holkar airport in driving rain, when it had been raining for days in that city.

The plane touched down successfully, but just couldn't slow down. It finally skidded off the runway, injuring five of its 49 passengers. Similarly, a Sahara aircraft skidded off the runway and got stuck in the muck in Mumbai last year.

With India adding around 12,000 flights each year, the number of skids and 'incidents' is likely to go up, not down. The Sao Paulo tragedy has raised a very timely question: how safe are Indian runways? While the Airports Authority of India operates 124 runways, state governments own 158 and private parties 63.

The two most unsafe airports in the country - according to aviation industry sources - are Pune and Patna, both recently declared 'international' airports. Patna, particularly, has just a 6,411-foot runway. According to reports, trees on land belonging to Union Railway Minister Lalu Prasad's in-laws intrude into the safety funnel of the airport's instrument landing system as aircraft execute the approach.

But it's not as if the rest of the airports in India are up to standard. Even the country's 'long' runways don't make the grade. One example is at Mumbai's airport, considered one of the best in the country. Singapore Airlines, for example, does not land on Mumbai airport's runway 14 because the control tower is too close to it. It is over 9,000 feet long, but only 7,200 feet are available for landing. To make things worse, the end of the runway is often waterlogged and slippery.

Compared to a dry runway, the safe landing distance on a wet runway requires a 30 per cent longer length. But this is not taken into account by safety authorities. 'Grooving' the runway to increase surface friction and drain away standing water is not done in India.

The system of cutting transverse grooves into the landing surface was taken up on short runways in the US after the National Aeronautics and Space Administration (NASA) conducted a series of tests aimed at improving friction between airplane tires and runway surfaces, in order to enhance braking performance. It found that the grooves give a performance that approaches that of a dry runway.

However, there is a much smaller chance of a Brazil-like situation in India, where the plane ploughed into a crowded neighbourhood and caused deaths on the ground, because at very few airports are buildings located so close to the runway.