A Virgin Atlantic plane returned to Heathrow earlier this week after it emerged the first officer had failed to complete its final flight test.
The Airbus A330 plane was almost 40 minutes into its journey to New York on Monday when the two pilots on board realized the “assignment error”, the airline said.
The VS3 flight had reached the skies over Ireland before returning to Heathrow and landed more than an hour and a half after taking off.
A replacement for the first officer was found, and the plane took off again for New York.
Virgin Atlantic insists that safety was not compromised.
The initial first officer joined the carrier in 2017.
He was fully qualified under UK aviation regulations, but had not completed a final assessment flight which is part of the airline’s internal requirements.
Flight VS3 was reversed because the captain had not been designated as the trainer.
Control of an aircraft is usually shared between a first officer and the captain, but the captain has ultimate responsibility for what happens on a flight.
A Virgin Atlantic spokeswoman said: “Due to a roster error, flight VS3 from London Heathrow to New York-JFK returned to Heathrow on Monday 2 May shortly after takeoff.
“The qualified first officer, flying alongside an experienced captain, was replaced by a new pilot to ensure full compliance with Virgin Atlantic’s training protocols, which exceed industry standards.
“We apologize for any inconvenience caused to our customers, who arrived two hours and 40 minutes later than scheduled as a result of the crew change.”