The King has handed his heir Prince William a senior military role closely linked to younger son Prince Harry in a rare joint appearance that has sparked some controversy.

The King presented William with the title of Colonel-in-Chief of the Army Air Corps, a position that the monarch held for 32 years.

The role makes William the head of the regiment that his brother Harry served in during his time in the British Army.

The presentation was made at the air base where Harry learned to fly, and in front of an Apache helicopter – which was what Harry piloted during his two tours of Afghanistan.

The appointment was watched by service personnel at the Army Flying Museum in southern England on Monday (UK time).

The King, 75, did not mention Harry but gave a glowing endorsement of the Prince of Wales saying: “He’s a very good pilot indeed.”

“I do hope you’ll go from strength to strength with the Prince of Wales as your new Colonel-in-Chief.”

It comes as Prince Harry last week was unable to meet with his father during a visit to London for his Invictus Games, reportedly due to the King’s busy schedule.

William is a former helicopter search and rescue pilot for Britain’s Royal Air Force.

Harry rose to the rank of Apache helicopter commander during his decade of service and was deployed to Afghanistan from 2007-2008 and 2012-2013.

It had been widely thought Harry would take on the role until he stepped back from royal duties in 2020 and moved to the US with wife Meghan Markle.

Father and son in front of an Apache helicopter as the King hands over his title. Photo: Getty

The visit was the King’s latest engagement since he returned to work at the end of April, almost three months after Buckingham Palace announced he was being treated for an unspecified type of cancer.

It was the first father-and-son public engagement since 2022.

William, 41, had also taken a break from official duties for several weeks in March and April, choosing to spend time with and care for his wife Kate, after she revealed she was having preventative chemotherapy for cancer.

He said on Friday she was “doing well”.

At Monday’s handover, the King said he was saying goodbye with “sadness” but the Army Air Corps would go from “strength to strength” under the Prince of Wales.

“Look after yourselves and I can’t tell you how proud it has made me to have been involved with you all this time,” he said.

The Prince of Wales in his military uniform. Photo: Getty

The title transfer was announced last August after the King’s accession to the throne upon the death of his mother, Queen Elizabeth.

William spent time with the Corps, viewing training, equipment and hearing from soldiers later on Monday.

He changed into his military uniform and climbed into the co-pilot seat of an Apache.

-with AAP