Prince William is fulfilling a lifetime ambition after beginning training to become a pilot.
After the RAF, Prince William will spend time with the Navy
The 25-year-old Royal has started intensive training with the RAF, where he will learn how to fly fixed-wing aircraft and helicopters.
Flying Officer Wales is following in the footsteps of his father, Prince Charles, and uncle, Prince Andrew, who both trained as pilots.
Until now, Prince William has spent his military career on solid ground as troop commander and second lieutenant with the Household Cavalry's Blues and Royals.
But in preparation for his future role as head of the entire Armed Forces, the prince will gain experience with both the RAF and, later in the year, the Royal Navy.
As his four-month course began, Clarence House released photographs of him taken during pre-training tests at RAF Cranwell in Lincolnshire in November.
In one, he is seen in the cockpit of an aircraft and in another, he appears in his full RAF uniform.
Along with about 11 other students, William will first take the controls of a propeller driven Grob 115E light aircraft, known as the Tutor.
Sqn Ldr Roger Bousfield, who will be William's instructor, said: "Students need to have good hand-eye co-ordination, confidence, decision-making skills and 'captaincy' - being able to cope with things, react well and react quickly."
"The first thing is to familiarise Flying Officer Wales with the plane, get him used to the controls and what they can do and very quickly we will go into acrobatics - looping the loop is one of the fun things we'll be doing."
After the Tutor, William is due to move to RAF Linton-on-Ouse in North Yorkshire, where he will be taught to handle the faster, more powerful Tucano T1 plane.
And finally, he will go to RAF Shawbury in Shropshire for training in the Squirrel HT 1 helicopter.
Instructor Sqn Ldr Rich Allison said: "He'll have to forget about moving and learn to hover."
Like all other students at RAF Cranwell, William will live in the mess.
There is a bar on site but students are bound by the strict "bottle to throttle" rule which bans alcohol for 12 hours before any flight.
Gp Cpt Nick Seward, Commandant of the Central Flying School, said he wanted the prince to gain an understanding of the RAF's ethos and how it differs from the Army.
"If successful, he will be awarded his RAF wings and in anticipation of this, a graduation ceremony is planned for April," Gp Cpt Seward said.
After his training, Flying Officer Wales will spend time with several front-line units, including search and rescue and fighter aircraft.
Usually pilot training takes three to four years, and Sqn Ldr Kevin Marsh, who is overseeing his attachment, said the short course would be "pretty tough".
"We have adapted the course and we have cut out anything superfluous to his specific needs because we're not teaching him to be an operational pilot - we're teaching him to be a competent pilot," Sqn Ldr Marsh said.
Prince Charles earned his RAF wings in 1971, while Prince Andrew flew Sea King helicopters during the Falklands War, acting as a decoy target to protect British ships from missile fire.
Before travelling to RAF Cranwell, William visited patients and staff evacuated from the Royal Marsden Hospital after the fire there last Wednesday.
He became president of the Marsden last year, a post previously held by his mother Diana, Princess of Wales.