It marks the second fatal incident at an Arizona airport in the past 10 days. On Feb. 10, the pilot of a private jet owned by Mötley Crüe singer Vince Neil was killed after a runway collision between two aircraft at Scottsdale Airport.

Of the 5,100 public airports across the country, only about 10% have air traffic control towers staffed by people who direct the flow of traffic.

As investigations into the Arizona mid-air collision continue, debates over air traffic safety, regulation, and infrastructure modernization remain front and center.

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.