A midair collision in Arizona prompts questions about air traffic control towers [Video]

Tens of thousands of planes take off, land and perform touch-and-goes at the Marana Regional Airport in southern Arizona every year. Without an air traffic control tower, it’s a calculated dance that requires communication by pilots.

Two small planes collided in midair over one of the runways on the outskirts of Tucson last week. One hit the ground and caught fire, sending up a plume of black smoke. The remains of two people were found in the charred wreckage. The other plane was able to land, with those occupants uninjured.

The collision was the latest aviation mishap to draw attention in recent weeks. The circumstances vary widely with each case, however, and experts who study aviation accidents say they don’t see any connection between them.

Chatter over the airwaves has provided some clues about what happened in Arizona. A chief flight instructor who was in the air with a student that day heard the commotion over the radio: One plane …