Prince William is trading in his flight suit for more formal attire as a younger generation of royals takes on the ceremonial duties of their older relatives.

Pilot William Wales, as he was known on the job with the East Anglian Air Ambulance, worked his last shift on Thursday. Often on duty for over nine straight hours, the second heir to the throne has been responsible for helicoptering medical crews to serious emergencies for about two years.

William penned a heartfelt goodbye to his colleagues, which was published on Thursday by a local newspaper. He reflected on meeting Britons under the direst of circumstances, sharing moments of extreme emotion, marvelling at the skill of emergency surgeons, and bearing witness to death and tragedy.

“One of the first call outs I made was to a young man who had committed suicide; it was an incredibly tough day and had a profound effect on all of us, not least in my determination now to draw attention to this issue,” he wrote in the East Anglian Daily Times.

“We are sent to only one per cent of ambulance call outs, where having a trauma team and getting the hospital to the patient quickly, can mean the difference between life and death” he wrote. “I have watched our medical team perform surgery on a patient within minutes of jumping off the helicopter -- their level of skill is astounding.”

William recalled the first time he heard the emergency line ring on base, and the accompanying feeling of pride in knowing that his swift actions could save the lives of his countrymen. He spoke of one such call where his team was first on the scene of a serious car crash.

“Another rescue that sticks in my mind was to a young man who was involved in a road accident,” William wrote. “His uncle in the car with him sadly didn’t survive, and I was sure that from what we were faced with he wouldn’t either -- but thanks to the skills of our medical team he is alive today.”

As William takes on full-time royal duties, another member of the family is stepping aside. His grandfather Prince Philip will attend his final public engagement next week at Buckingham Palace. The 96-year-old is said to have appeared at more than 22,000 royal events.

Kensington Palace and East Anglian Air Ambulance tweeted a series of messages on Thursday documenting William’s final evening on the job. They include pictures of the Queen inspecting a rescue helicopter, William running his final pre-flight checks on Anglia One, and shots of the prince posing with colleagues.

William ended his written tribute by thanking the first responders he served with for their dedication to a physically and mentally demanding job.

“As I hang up my flight suit, I am proud to have served with such an incredible team of people, who save lives across the region every day.”