Sacramento International Airport officials say "don't be alarmed" if you see some commotion on the tarmac this afternoon.

Gina Swankie with the airport says they're staging a simulated emergency to test the performance of first-responders.

"This particular scenario is a drill. It's not a real, active emergency. But it is not going to be unrealistic. People will be out and about at the airport and see emergency vehicles in play and possibly some people going back and forth playing through the scenario." 

The Federal Aviation Administration requires the airport to conduct a full-scale emergency exercise every three years.

Today's drill will be held sometime between 1 PM and 5 PM. Swankie says if a real emergency happens during the planned exercise, the drill will immediately be stopped so that first responders can react.