Darnell works as an air traffic controller at Denver International Airport.
His office is located high up in a tall control tower.
From the large windows, he can watch many planes in the sky.
Darnell spends most of his day looking at glowing radar screens.
These screens show the exact location and speed of every airplane.
Because the airport is a busy travel center, he must pay close attention.
He uses a special radio to talk to the pilots constantly.
Darnell tells them exactly when it is safe to land their planes.
He also gives them clear instructions to take off from the runway.
Sometimes, the weather in Colorado changes very quickly during the day.
A perfectly clear morning might suddenly turn into a snowy afternoon.
When the weather becomes bad, Darnell has to stay completely calm.
Heavy rain or thick clouds can make flying much more difficult.
He speaks slowly and clearly so the pilots understand his directions.
Darnell guides the airplanes carefully through the dark and cloudy skies.
He always makes sure that every plane stays a safe distance apart.
Working in the control tower requires a lot of focus and training.
Darnell loves his job because he helps passengers travel safely every day.
He feels proud when he sees a plane land smoothly on the ground.