The Federal Aviation Administration said on Tuesday that it was investigating an incident in which two Southwest Airlines jets narrowly missed each other at Nashville International Airport.

The close call happened on Saturday evening, when an air traffic controller inadvertently directed one plane into the other’s path, and the two aircraft passed within 500 vertical feet of each other, according to the flight-tracking website Flightradar24 and the F.A.A.

“The crew of Southwest Airlines Flight 507 initiated a go-around at Nashville International Airport and then received instructions from air traffic control that put the flight in the path of another airplane that was departing from a parallel runway,” the Federal Aviation Administration said in a statement.

Southwest Airlines said Flight 507 had aborted its landing to try again, known as a go-around, because of gusty winds. While doing so, the company said in a statement, the plane’s pilots reacted to “an onboard traffic alert to avoid conflicting with Southwest Flight 1152.” Flight 507 landed safely, and Flight 1152 continued, completing its trip to Knoxville, the airline said.

The crews of both planes were alerted to the potential collision by an onboard system known as the Traffic Avoidance Collision System, the F.A.A. said. The system warns pilots if another plane is dangerously close, and directs them to ascend or descend to avoid it. The systems, which have been in use for decades, are required on large commercial airplanes.

Southwest is the dominant commercial airline at Nashville International, accounting for more than half of the average daily flights at the airport in fiscal year 2025.

The incident was one of the latest brushes with potential disaster in American airspace, as staff shortages, soaring prices and government shutdowns have put the nation’s air travel infrastructure under extreme pressure. So-called “close calls” between airplanes have become more common, a high-stakes problem underscored by a nationwide shortage of air traffic control operators. A 2023 New York Times investigation found these sorts of near-misses occur several times a week, far more often than previously believed.

Last month, an Alaska Airlines and FedEx plane narrowly missed each other while landing at Kennedy International Airport in New York. Days later, two pilots were killed when a Canada Air jet collided with a fire truck on the runway at LaGuardia Airport.

Ali Watkins contributed reporting.