On July 20, 2020, a United Airlines Boeing 787-10 approached a runway of Paris-Charles de Gaulle Airport (CDG) on which an Easyjet Airbus A320-214 was waiting to take off. 

The French Bureau of Enquiry and Analysis for Civil Aviation Safety (BEA) released its final report on the incident on July 19, 2021.

The United Airlines Boeing 787 was carrying out flight UA57 from Newark Airport (EWR) to Paris-Charles de Gaulle Airport (CDG). 

As the investigators found out, it was the mistake of an air traffic controller that oriented the Boeing 787 towards the wrong runway. This day, landings were carried out on runway 09L and take-offs on runway 09R. 

However, shortly before the arrival of the United flight, another Boeing 787 operated by Air France demanded to land on runway 09R, the longest of the two, due to a technical problem.

On the first contact with the crew of the United Airlines Boeing 787 on an ILS approach on runway 09L, the controller made a slip and cleared the crew to land on runway 09R instead of runway 09L, the report explains. 

“Understand cleared to land 09 Right, sidestep for 9 Right United 57,” the flight crew read back, hoping for a confirmation that they would have to do a side-step maneuver. They did not receive an answer from the controller.

In the meantime, the controller cleared the crew of an Easyjet Airbus A320 to line up for takeoff on runway 09R, as the United flight was engaging their side-step maneuver. 

Fortunately, the Easyjet crew saw the Boeing 787 on approach and questioned the controller about its presence before adding “Go around 09R, go around.”

The United flight crew which had already located the Airbus A320 on the runway aborted its approach. The Boeing 787 flew over the Airbus A320 at a height of approximately 300 feet (91 meters).

The BEA found that the position of the controller, which had no visual on the runways, may have contributed to the mistake. Moreover, given the COVID-19 health crisis period and the decrease in traffic, the controller might have lacked practice. Finally, the usage of the word “Understand” instead of “Confirm” from the flight crew failed to raise the controller’s attention. The report praises the vigilance of the two crews, which helped prevent a potential runway collision.

As a side note, the BEA pointed out the fact that Eurocontrol recommends flight crew to re-confirm the clearance with ATC rather than repeating what they heard.