Air travel is such a common part of modern life that it’s easy to forget all the miraculous technology and communication infrastructure required to do it safely. But recent crashes, including near Washington, DC, and in San Diego — not to mention multiple near misses — have left many fliers wondering: Is it still safe to fly?

The U.S. Air Traffic Control (ATC) system, once a symbol of aviation excellence, is now facing a crisis marked by staffing shortages, […]