Queen Elizabeth II’s biggest fear during her royal tours and engagements has just been revealed.

Royal biographer Robert Hardman, the author of “Queen of the World,” said that Her Majesty doesn’t particularly enjoy riding the plane. She is also famously stoical about the dangers of the royal life while on her excursions.

“If St. Christopher, the patron saint of travelers, can afford any extra protection then so much the better,” he said.

Hardman also referenced former royal photographer Reginald Davis, who covered the majority of the Queen’s early royal tours. Davis revealed that the Queen once told him that she never felt relaxed while flying.

But even though she is not a huge fan of traveling by plane, the monarch enjoys doing her royal duties when she gets to her destination. Charles Anson, the Queen’s former press secretary, told the Radio Times that Her Majesty actually enjoys traveling – just not by plane.

“She is genuinely curious about people, their different cultures, traditions, and quirks,” he said.

In related news, the monarch also made headlines this week after it was revealed that her husband, Prince Philip, got into an accident. According to CNN, the 97-year-old retired royal was the one driving his vehicle when it crashed and flipped to the other side.

The accident took place around 10 a.m. on a public road near the Queen’s Sandringham estate in Norfolk. Photos of the Duke of Edinburgh’s Land Rover were also released online. But it has been confirmed that Prince Philip was unhurt.

Following the collision, Prince Philip saw a doctor. Prior to this, he and his female companion were both given breath tests and passed.

Meanwhile, royal fans and critics couldn’t help but wonder whether or not Prince Philip should still be allowed to drive. The United Kingdom requires drivers older than 70 years old to renew their license every three years. Prince Philip is required to have a driver’s license, but the Queen doesn’t.

“The decision to hang up your keys is a tough one but should be based on personal advice from your GP and family rather than being based on some arbitrary age,” Edmund King, president of UK’s Automobile Association, told The Telegraph.

Queen Elizabeth II Queen Elizabeth II enjoys traveling but not by plane. Pictured: The Queen smiles as she arrives before the Opening of the Flanders' Fields Memorial Garden at Wellington Barracks on November 6, 2014 in London, England. Photo: Getty Images/Stefan Warmuth-WPA Pool