United Express routinely flies into the Eastern Iowa Airport (KCID) generally from Chicago and Denver hubs. These photos of arriving and departing aircraft are from last week's visit to the airport when a special NASA jet flew in for avionic testing.
United Express flies Embraer ERJ-145s planes in and out of the major hubs to spoke metro markets like Cedar Rapids.
In the foreground is a waiting area where departing planes stop to receive final permission to get airborne. I'm no expert but believe that departing pilots talk to both the Cedar Rapids tower and regional control in Chicago for the go-ahead to fly.
Arriving aircraft make their way past the tower and eventually to the passenger terminal. In years past United Airlines flew 737s to Cedar Rapids. Now smaller capacity, but higher occupancy aircraft continues the decades long tradition of serving the City of Five Seasons.