The Federal Aviation Administration (FAA) is investigating two separate incidents where commercial aircraft had to take evasive action to avoid mid-air collisions.

One incident involved two Southwest Airlines jets just north of Nashville International Airport. The FAA stated that the crew of Southwest Airlines Flight 507 initiated a go-around at Nashville International Airport and then received instructions from air traffic control that placed the flight in the path of another airplane departing from a parallel runway. Both flight crews responded to onboard alerts, with the incident occurring around 5:30 p.m. local time on Saturday, April 18. The planes came within 500 feet of each other.

Air traffic data and ATC recordings indicate that a controller inadvertently turned a Southwest Boeing 737 Max 8 into the path of a Southwest Boeing 737-700 taking off from the airport. Pilots in both aircraft reported taking evasive action in response to Resolution Alerts (RAs) from their on-board collision avoidance systems.

The Boeing 737 Max 8, Southwest Flight 507, was en route from Myrtle Beach to Nashville and had been cleared for landing on Runway 2 Left. For unknown reasons, the data suggests the flight crew decided to execute a “go-around” instead of landing. At the same time, the Boeing 737-700, Southwest Flight 1152, was taking off for Knoxville from Runway 2 Right, just east of the other aircraft.

Seconds later, air traffic control directed Flight 507 to turn right, placing it into potential conflict with Flight 1152. Apparently realizing his mistake, the controller ordered Flight 507 to climb from 2,000 feet to 3,000 feet while directing Flight 1152 to hold at 2,000 feet. “We’re already past it,” Flight 1152 responded. The controller replied, “He’s already in the turn. Flight 507, descend and maintain 2,000.” “Down to 2,000,” Flight 507 quickly responded.

A second incident occurred as two commercial jets approached New York City’s John F. Kennedy International Airport. The planes were forced to abort landings. According to the FAA, Republic Airways Flight 4464 (operating as American Airlines Flight 4464) performed a go-around after missing its intended approach path and flying too close to Air Canada Express Flight 8554, which had been cleared for landing on a parallel runway. Both flight crews responded to onboard alerts during the incident, which happened around 2:35 p.m.

The FAA stated that the information is preliminary and the incidents remain under investigation. Republic Airways reported that the flight aborted its initial landing attempt and executed a go-around during approach into JFK. “During their approach into JFK, the crew…received a resolution advisory,” the airline said. “They complied with the advisory and, consistent with our training and procedures, executed a go-around to land without further incident.” Air Canada stated that its flight from Toronto received a traffic warning and direction from air traffic control during approach into JFK. “The crew took immediate action,” the airline said. “Safety is our top priority and our crews are well-trained to deal with many operational situations such as this.” The airline added that the flight landed safely.