Two Delta Air Lines aircraft came into close proximity at Hartsfield–Jackson Atlanta International Airport on Monday evening after a landing was aborted, triggering onboard collision avoidance alerts in both cockpits.
The incident involved Delta Flight DL1568, a Boeing 737-900ER registered N937DZ operating from Pittsburgh to Atlanta, and Delta Flight DL2472, an Airbus A321 registered N333DX which had just departed the airport with destination Rochester. According to air traffic control recordings and flight tracking data, both aircraft received Traffic Collision Avoidance System (TCAS) Resolution Advisories (RAs) instructing their crews to take immediate evasive action.
Go-around after runway concerns
Flight DL1568 had already experienced a disrupted journey after severe weather forced it to divert to Chattanooga Metropolitan Airport for several hours before continuing to Atlanta.
As the aircraft approached for landing, the pilots queried air traffic control after noticing another aircraft on or near the runway.
“Somebody on the runway?” the crew asked.
Although the tower advised that the aircraft was exiting the runway, the Delta crew elected to perform a go-around, a standard safety procedure in which a landing is discontinued and the aircraft climbs away for another approach.
Departure placed aircraft on converging paths
At the same time, Delta Flight DL2472 had departed from a parallel runway. Air traffic control instructed the departing aircraft to turn right and climb to 4,000 feet.
Moments later, the crew of Flight DL1568, which had announced its go-around, received the same instruction to turn right and climb to 4,000 feet, placing both aircraft on converging flight paths.
The TCAS systems aboard both aircraft then issued Resolution Advisories, requiring the pilots to take immediate avoiding action independently of air traffic control instructions.
Controllers subsequently issued revised vectors to separate the aircraft.
According to Flightradar24 data, the two aircraft came within approximately 1,800 feet (550 metres) horizontally and 600 feet (183 metres) vertically before increasing their separation.
FAA opens investigation
Delta emphasised that its crews responded in accordance with established procedures.
“During the go-around, the flight crew manoeuvred in accordance with established procedures while maintaining safe operations,” the airline said in a statement. “Our crews train extensively to handle uncommon scenarios like this.“
The Federal Aviation Administration has confirmed it has opened an investigation into the incident to determine the sequence of events and whether any procedural or air traffic control issues contributed to the loss of separation.
Go-arounds are a routine and safe manoeuvre in commercial aviation. However, TCAS Resolution Advisories are relatively rare and indicate that aircraft have come close enough for onboard systems to direct pilots to take immediate action to maintain safe separation. The investigation will examine why both aircraft were assigned converging climb paths following the aborted landing.