Simulated snow fell at Honolulu Airport on Wednesday.

So did rain.

And day suddenly turned to night.

It was all part of scenarios fabricated to test air-traffic controllers in training.

Federal Aviation Administration officials unveiled Honolulu’s $1.5 million state-of-the-art control tower simulator, which Hawaii’s trainees now use rather than practicing with real air traffic.

"It’s a lot less stressful, teaching them here," said Richard Coppola, an instructor and controller.

"You don’t know what a trainee is going to do," added instructor and controller Daniel Nakamitsu, adding that it’s difficult to learn in live air traffic.

The FAA demonstrated the simulator’s capabilities for the media Wednesday as part of the FAA’s commemoration of the 75th anniversary of federal air traffic control, established in July 1936.

The tower simulator system, in a room at the Honolulu Control Facility at the airport, has been used to train 11 new controllers since October 2009. Twelve more will be training on it next year. (The FAA has 14 simulators at its Oklahoma City training academy.)

The Honolulu simulator is one of 22 at or near major U.S. airports.

Air traffic controllers displayed the simulator’s virtual 360-degree view of Honolulu Airport’s runways and beyond, from the Waianae Mountain Range to Diamond Head, just as it is seen from the windows of the actual control tower built in 1984.

Trainees, wearing headsets, issued commands to aircraft, and can hear remote "pilots" respond to their commands.

The simulators also help veteran controllers train on new procedures or unusual scenarios, such as runway closures.

They created and dealt with a virtual emergency involving a plane landing with engine trouble, turned day to night, made it rain and even snow while planes arrived and departed.

The simulator replaces the traditional instruction method, which uses tabletop models of the airport and model airplanes.

Neil Okuna, supervisor at the facility, said Ho­no­lulu’s simulator allows controllers to practice handling a mix of landings, including military aircraft.

The system also can train new controllers to handle air traffic during Hawaii’s less common kona winds. Since planes must take off and land into the wind, kona winds mean "we need to turn the airport around," Okuna said.

"We don’t have many opportunities to practice that and mimic that configuration," said operations manager Dave Sakasegawa.

Okuno said the system "shaves off a couple of weeks of training," providing new controllers "all kinds of scenarios without impacting real traffic."

It eliminates the need for the instructor to intervene to avoid a possibly hazardous situation, allowing trainers to replay scenarios and students to see the cause and effect of their actions.

FAA spokesman Ian Gregor said the simulator has hundreds of scenarios programmed into it, and it will be programmed in the future for the control towers on Maui and in Hilo.

The FAA is scheduled this year to add four more simulator locations. It plans to hire 10,000 new air traffic controllers by 2020.