Now arriving: Airport control towers with no humans inside

NEW YORK -- Passengers landing at remote Ornskoldsvik Airport in northern Sweden might catch a glimpse of the control tower -- likely unaware there is nobody inside.

The dozen commercial planes landing there each day are instead watched by cameras, guided in by controllers viewing the video at another airport 90 miles away.

Ornskoldsvik is the first airport in the world to use such technology. Others in Europe are testing the idea, as is one airport in the United States. While the majority of the world's airports still will have controllers on site, experts say unmanned towers are coming. They'll likely first go into use at small and medium airports, but eventually the world's largest airports could see an array of cameras mounted on a pole replacing their concrete control towers.

The companies building these remote systems say their technology is cheaper and better than traditional towers.

"There is a lot of good camera technology that can do things that the human eye can't," Pat Urbanek, of Searidge Technologies, said. "We understand that video is not real life, out the window. It's a different way of surveying."

Cameras spread around an airport eliminate blind spots and give controllers more-detailed views. Infrared can supplement images in rain, fog or snow and other cameras can include thermal sensors to see if animals stray onto the runway at the last second.

None of those features is in the Swedish airport yet because of regulatory hurdles.

Ornskoldsvik Airport is a lifeline for residents who want to get to Stockholm and the rest of the world. But with just 80,000 annual passengers, it can't justify the cost of a full-time control staff -- about $175,000 a year in salary, benefits and taxes for each of six controllers.

In April, after a year and a half of testing a system designed by Saab, all the controllers left Ornskoldsvik. Now, an 80-foot tall mast housing 14 high-definition cameras sends the signal back to the controllers, stationed at Sunvsal Airport. No jobs have been eliminated, but ultimately such systems will allow tiny airports to pool controllers.

Old habits are hard to break. Despite the ability to zoom in, controllers instinctively grab their binoculars to get a closer look at images on the 55-inch TV screens. And two microphones were added to the airfield at Ornskoldsvik to pipe in the sounds of planes.

"Without the sound, the air traffic controllers felt very lost," said Anders Carp, head of traffic management for Saab.

The cameras are housed in a glass bubble. High pressure air flows over the windows, keeping them clear of insects, rain and snow. The system has been tested for severe temperatures: 22 degrees below zero and, at the other extreme, a sizzling 122 degrees.

Niclas Gustavsson, head of commercial development for LFV Group, the air navigation operator at 26 Swedish airports, said digital cameras offer numerous possibilities for improving safety.

Computers can compare every picture to the one a second before. If something changes -- such as birds or deer crossing the runway -- alerts are issued.

"Maybe, eventually there will be no towers built at all," Gustavsson said.

Saab is testing -- and seeking regulatory approval -- for remote systems in Norway and Australia and has contracts to develop the technology for another Swedish airport and two in Ireland.