Air traffic controllers in Changi Airport will soon be guiding planes to take off and land without having to actually see the aircraft from a control tower.

The technology could even allow controllers to do the work from distant locations like Jurong or Seletar.

A $7 million trial by the Civil Aviation Authority of Singapore (CAAS) will work on developing and testing a smart digital tower prototype.

CAAS has awarded the contract to Britain-based air traffic management firm Nats, which manages London's Heathrow airport.

CAAS yesterday said the trial is expected to start early next year, and will take about 22 months to complete. It will then evaluate the operational feasibility before determining if the technology is suited for a busy airport like Changi.

So far, only small airports have adopted similar technology. Ornskoldsvik, a small airport in Sweden, is the first airport in the world where flights are controlled remotely. Planes taking off or landing there are guided by air traffic controllers who are nearly 170km away, in the town of Sundsvall.

Other countries studying the remote tower option include Hungary, Britain, the United States and Germany.

A smart digital tower, equipped with a range of functions and features, can help enhance air traffic management, the safety of runway and ground operations, and increase operational efficiencies at Changi Airport, CAAS said.

The Nats contract includes the set-up of multiple fixed-position cameras to feed live video images, which will provide a similar view to what air traffic controllers now see from the control tower.

The trial will also employ advanced camera and video-stitching technologies that will enable better display of information. For instance, the video cameras will be able to automatically pan, tilt, and zoom, to enable a closer look.

CAAS director-general Kevin Shum said: "In concert with Singapore's Smart Nation drive, we are leveraging digital technology to transform the aviation industry...

"We are excited by the possibilities and remain committed to working with our industry partners to provide quality air traffic management services without compromising on safety and service levels."

The tender for the digital tower prototype opened on Feb 28. It attracted three bids, which were evaluated on various criteria, such as technical expertise, company track record, and price competitiveness.