Breaking News:Prince William and King Charles Clashed Over Use of Helicopter for Kate Middleton and Their Children, New Book Claims

The alleged disagreement between the royals is detailed in a new biography about the Princess of Wales

King Charles and Prince William were involved in a dispute earlier this year surrounding the safety of the royal family flying in a helicopter, a new book claims.

According to Robert Jobson’s soon-to-be-released biography, Catherine, The Princess of Wales, the King, 75, “raised concerns” with William, 42, over his helicopter use with Kate Middleton and their children, Prince George, Princess Charlotte and Prince Louis, that sparked a tense disagreement between the pair.

In an excerpt from Jobson’s book, per The Daily Mail, King Charles brought up his worries on the matter after coming to terms with his mortality following his cancer diagnosis, which was announced in February.

The King even presented experienced pilot William with “a formal document acknowledging the risks involved and taking full responsibility for his actions” amid their dispute, the new book claims.

Charles’ concerns echoed that of his late mother Queen Elizabeth, who previously requested William not fly with his family on a helicopter from Kensington Palace to his former residence of Anmer Hall in Norfolk, which is a 115-mile journey, according to Robson.

Queen Elizabeth “didn’t hold back” on her opinion, an aide shares in the new book, after being haunted by the 1967 helicopter crash that killed her flight captain.