June 14, 2008

Freak Spell Hits Flights

By Neha Lalchandani

NEW DELHI: When it comes to diversions and delays in Delhi, fliers normally dread the winter months when fog disrupts operations at the IGI Airport. However, this May, when unexpected and "freakish" weather made Delhiites forget the summer heatwave, the Capital allegedly saw 82 flight diversions, more than those witnessed in the entire fog duration last winter.

According to airport officials, however, May saw only about 20 diversions, which is still a high number, considering that last fog season, Delhi saw about 30-35 diversions.

According to weather experts, thunderstorms are the worst of aviation hazards. "Head winds gets really strong during thunder activity so landing and take-off is virtually impossible. The cyclonic storm, when it is receding, moves in the opposite direction and there are chances of aircrafts crashing as well," said an expert.

This May especially, since this kind of weather was not expected, airlines were completely caught off guard. Officials said that Delhi did not have monsoon planning, unlike cities like Mumbai and Kolkata, where such weather activity is common. Unfortunately, unlike precautions and measures that can be taken for flying in the fog, cannot be taken with rough weather.

"Every aircraft has flying limitations and one kind of aircraft may be able to handle weather changes better than another. Heavy rains bring down visibility, but one can't use the instrument landing system at all points since crosswinds that form during such turbulence restrict its use. While storms may last for a short while, they normally have a more drastic impact on aviation," said Capt Vikram Yadav, general secretary, Indian Commercial Pilots Association.

The other problem, say pilots, is that the storm cells shift with the wind, making it difficult to avoid them. The aircrafts also have limited space, since weather above and in surrounding areas can also be stormy. "Landing in such a situation is extremely tough, so pilots prefer taking a diversion," said Yadav.

Airlines have a problem with fuel as well, since the unexpected weather means that nobody knows which areas are affected and if diverted, where the aircraft could land. "Carrying extra fuel means that other load in the aircraft has to be reduced. Secondly, if the weather is similar over nearby cities like Lucknow and Jaipur, where aircraft are normally diverted, the pilot would have to go to a destination much further off," said aviation experts. Even for ATCs rain and storm cause massive problems. Experts said that due to clouds, the radar shows duplicate images.

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