Imagine being 20,000 feet in the air and learning that your pilot hasn’t completed training. That’s what happened to passengers earlier this week while aboard Flight VS3.

On Monday (May 2), passengers on a Virgin Atlantic flight were about 40 minutes into their trip when crew members learned one of their pilots had not completed their final flying test. The flight was traveling from London to New York’s JFK Airport.

According to The Sun, a source said, “You could have cut the tension in the cockpit with a knife.”

Another source told the outlet, “It was embarrassing for everyone and the passengers were furious” when speaking about how the plane had to turn around to get a replacement pilot.

A spokesperson for the airline told CNN that the issue was due to a “rostering error.”

The spokesperson said, “Due to a rostering error, Flight VS3 from London Heathrow to New York-JFK returned to Heathrow on Monday [May 2] shortly after take-off.”

“The qualified first officer, who was flying alongside an experienced captain, was replaced with a new pilot to ensure full compliance with Virgin Atlantic’s training protocols, which exceed industry standards,” the spokesperson added.

In the official statement, it was revealed that the pilot had started with the company in 2017. Although they were qualified under UK standards, they still were required to pass a “final assessment” flight.

The company claims that the flight captain on board with the pilot was “highly experienced” and had been with Virgin Atlantic for 17 years. According to reports, both pilots were fully qualified to operate an aircraft of that magnitude. The company also claimed that no aviation protocols or safety standards were breached during the incident.

The UK’s Civil Aviation Authority mirrored the company’s statements adding, “Both pilots were suitably licensed and qualified to undertake the flight.”

All passengers made it to their final destination unharmed, but because of the issue, the flight’s arrival time was delayed by almost three hours.