NEW DELHI, November 22: Alarm bells start ringing each time a bird is spotted anywhere near the airport. Men scurry along the runway bursting crackers, recorded distress signals of birds are switched on and all aircraft grounded. Work at the airport comes to a standstill as the birds are shooed off the runway. Despite all these ``bird scaring methods'' there have been five bird hit reports filed at the airport since the beginning of this year. Last year there were six hits reported and in 1996 seven. Though no aircraft has been lost yet, the Airports Authority of India (AAI) is not taking any chances.Last week three devices to scare away birds were installed along the most frequently used runway, 2810. The Zon LPG operated devices to repel birds have been imported from Holland and are now operational on an experimental basis at both the international and domestic airports. These ``scarecrow devices'' have replaced conventional methods used for scaring birds.Airport Director Nagar V. Sridhar explains: ``There was a time when we used recorded distress signals of birds to combat the problem. But today, this method has become ineffective. However, we did continue with the crackers''. Just a week ago, 20 bird scarers employed by the AAI would periodically walk down the runway bursting firecrackers or would shoot in the air to scare the birds off. This was done at the risk of the wild grass growing along the runway catching fire. All that is a thing of the past now. The Indira Gandhi airport has become the first civil airport to install the Zon system, along the lines of the one already operational at the Hindon Air Force base.A simple system, the Zon consists of a blow horn like device which is connected to a LPG cylinder. Once the timer is set, for a time frame ranging from 40 seconds to half-an-hour, there is a bang. With a 360 degree manoeuvrability and a linear 100-125 decibel level, the gadget is guaranteed to scare away birds in its vicinity. Of the three, one of the devices is stationary and the other two mobile.Bought at a cost of around Rs 36,000 each, airport officials claim that this mechanism is cost-effective. ``If we work out the economics, we can make 25,000 blasts for just Rs 285,'' says Sridhar. ``Fire crackers, on the other hand, were a more expensive proposition, with each costing us Rs 2.'' These devices have been installed at a time when population pressure around the airport is increasing. Airport officials are particularly concerned about the Dwaraka housing complex that has come up in the vicinity of the airport. Officials say that this housing complex will add to their bird trouble if there is any lapse in the garbage disposal process.``Nangal Durat and Mehram Nagar are two villages that are already situated right along the runway,'' explains an official. ``With poor cleanliness maintenance in most residential areas, the threat of birds increases''.Surveys conducted on bird behaviour indicate that after a hearty meal, birds like to rest in a quiet place, often away from the source of food. Also, in winter they like to rest with their stomachs on the tarmac, absorbing its warmth.Aware of these bird habits, AAI officials undertake weekly inspection rounds of the areas in the vicinity of the airport, along with representatives of the municipal corporation. The aim is to keep the areas surrounding the airport carcass and garbage free.
