Forecasting Birds

High-speed aircraft and jet engines just cannot cope with birds. In the U.S., the annual total of aircraft-bird collisions now exceeds 1,600, some of them resulting in injuries and even fatal crashes. The Air Force alone estimates that it spends about $5,000,000 per year to repair aircraft surfaces battered or even pierced by the high-velocity impact of large fowl; it costs another $4,000,000 to $5,000,000 to repair or replace jet engines that have been damaged by ingested birds. But scientific help is on the way for aircraft--as well as for the birds, which fare even worse in aerial collisions.

In Canada, where at least five Royal Canadian Air Force CF-104 jets have been destroyed in the past two years by collisions with birds, government-sponsored scientists have devised a new forecasting system that may enable pilots to detour around flocks of birds, much as they now avoid thunderstorms. With the aid of biologists, meteorologists and radar experts, Canada's Associate Committee on Bird Hazards to Aircraft last year converted the R.C.A.F. base at Cold Lake, Alta., into an electronic bird-watching station.

Tail-Wind Fliers. With a Polaroid-backed camera set up in front of a 50-mile-range radar scanner, the scientists shot a succession of twelve-minute time exposures. As a result, the bird echoes--which normally appear as indistinct dots on the radar screen--formed easily discernible lines on the film that enabled experts to determine the approximate density and direction of bird concentrations. Meteorologists and biologists were then able to predict the location of the flock for the following few hours and warn pilots of its presence. "The predictions are based on weather and migration patterns," explains Engineer Malcolm Kuhring, who is chairman of the committee. "The birds fly with tail winds; they fly the pressure patterns."

During the 1965 spring-and fall-migration periods, the R.C.A.F. forecaster at Cold Lake added bird forecasts to his regular weather bulletins, predicting the bird movements around the clock and rating their intensity numerically from zero (for clear air) to eight (for a dense flock). The forecasts proved to be 83% accurate during the spring tests, about 70% in the fall--percentages that would make any conventional weatherman justifiably proud. They so impressed the local R.C.A.F. flight commander that he agreed to call off night training flights if the bird intensity reached a rating of six.

Bird forecasting has now been established permanently at Cold Lake, and is being tried experimentally at bases in Toronto and London, Ont. Before long, Kuhring hopes, Canada will be equipped with a coast-to-coast network of forecast stations that can follow and predict the routes of flocks all the way from their nesting grounds in the North to the U.S. border, giving aircraft ample warning of the approach of the feathered hazard.

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