Why Prince William is causing increasing alarm at the Palace, insiders tell RICHARD EDEN

It was a sight to cheer all those who cherish the Prince and Princess of Wales’s close relationship with their children.

On a scheduled British Airways flight to Barcelona during his half-term holiday from Eton College, Prince George was sat next to his father, Prince William.

Fellow passengers were delighted to see the heir to the throne, 44, and his 13-year-old son, the future king, spurning a private jet for the two-hour journey to Spain’s second city last week. The pair were apparently engaged in excited chatter as they discussed the event they were travelling to see: a Champions League football match between Barcelona and their beloved Aston Villa at the Spanish club’s Spotify Camp Nou stadium.

While I am among those who share the delight at the warm relationship between father and teenage son, there is something about the situation that sends a shiver down my spine.

It is the fact that the pair travelled together – something royal protocol suggests should not happen. The reason for the convention is compelling: the line of succession must be preserved above all else. Should an aviation disaster occur, multiple future monarchs could be lost at the same time, jeopardising the future of the monarchy.

Not only did Princes William and George travel on the same flight to Spain, but they are also understood to have flown on the same plane home.

It is certainly a departure from what happened when William reached the age of 12 – he stopped travelling with his father, King Charles.

The late Queen Elizabeth’s former pilot Graham Laurie revealed that William flew with his parents and brother, Prince Harry, until his 12th birthday in 1994. ‘After that, he had to have a separate aircraft,’ Laurie recalled in an interview on Hello! magazine’s A Right Royal Podcast.

The pilot said exceptions were made only when the Queen granted written permission for William to fly with his father.

Even worse than flying together on aeroplanes (which have an excellent safety record), William and his immediate family often travel on helicopters as a group, I am told by Palace insiders.

William won his general RAF pilot wings in 2008 after completing initial flying training on both fixed-wing aircraft and basic helicopters. By 2012, he had qualified as a Search and Rescue Operational Captain, giving him full command of RAF helicopters.

A year ago, he confirmed that he still piloted helicopters, explaining how flying was his ‘happy place’ as he reminisced with former air force colleagues.

During a visit to RAF Benson in Oxfordshire, he described how the sound of Sea King helicopters still went ‘straight to my heart’.

When asked if he still spent any time in the cockpit, William replied: ‘I do still fly, yeah – I keep my hours going. When you learn that skill set, you just don’t want it to go.’

Helicopters are far more dangerous than planes. As recently as June this year, three members of the Royal Navy died in a Merlin Mk4 helicopter that crashed during a training exercise in Devon.

My worries about William travelling with George may be shared by the King. According to the respected royal biographer Robert Jobson, the monarch raised concerns about his elder son’s ‘stubborn refusal’ to take his advice on safeguarding the succession.

Writing in his 2024 book – Catherine, the Princess of Wales: The Biography – Jobson reported: ‘Earlier this year, the King had raised concerns with his son about the wisdom of William using his helicopter to fly his entire family around the country.

‘An experienced pilot, William had upset the late Queen when he defied her request not to pilot his family the 115 miles from Kensington Palace to Anmer Hall, their home in Norfolk. The Queen, haunted by the 1967 crash that killed the Captain of the Queen’s Flight Air Commodore John Blount DFC (although no royals were on board), “did not hold back”, one aide said.’

Jobson added: ‘After being diagnosed with cancer, King Charles – perhaps reminded of his own mortality – echoed his late mother’s concerns.

‘And when William refused to stop flying with his family, Charles insisted that he sign a formal document, acknowledging the risks involved and taking full responsibility for his actions.’

Monarchists need no reminding that after Prince William and his children, the Duke of Sussex is next in line to the throne.

The prospect of Harry as King and Meghan as our Queen, after everything they’ve done to undermine the Royal Family, is enough to turn even the most ardent monarchist republican.