The Duke of Cambridge will return to the skies tomorrow as he begins his new job as an air ambulance pilot.
William began a civilian pilot course in September before undergoing dedicated 999-response training in order to take up the role with the East Anglian Air Ambulance (EAAA).
He has now completed the training and is expected to report for his first day of duty based at Cambridge Airport.
The former RAF search and rescue helicopter pilot will work as a co-pilot transporting patients to hospital from emergencies ranging from road accidents to heart attacks.
He will work alongside a pilot and a team of medics flying missions over Norfolk, Suffolk, Cambridgeshire and Bedfordshire.
The role will be his main job but his roster will take into account the duties and responsibilities he will continue to undertake on behalf of the Queen.
He is employed by Bond Air Services which operates the air ambulance on behalf of the charity and will be paid a salary which he will donate in full to good causes.
Speaking when the appointment was announced, Patrick Peal, EAAA chief executive, said the organisation would benefit both from William's skills as a pilot and from a boost to the charity's profile.
Mr Peal added: ''This is really good news for the charity and we're delighted His Highness has decided to fly with us.
''We are confident this will help raise the profile of the charity and other air ambulance charities in the region and across the UK.
''We're looking forward to him being part of the team.
''It is a very close-knit crew with the pilot operating closely with the doctor and paramedic so we need a strong team in every operation we go on.''
William, who was already qualified to be a captain or pilot of a Sea King helicopter, took unpaid leave in April following the first phase of his training with East Anglian Air Ambulance.
Following the birth of Princess Charlotte in May, he and Kate have spent much of their time away from the public eye at their home, Anmer Hall, on the Sandringham estate in Norfolk.
But following her christening earlier this month, he has completed a number of public engagements as well as being seen at Wimbledon with his wife.
The couple are expected to split their time between Anmer Hall and their apartment at Kensington Palace.
The charity recently launched its newest air ambulance, a H145 T2 helicopter, which will be flown by William and his fellow pilots.
The EAAA needs to raise £7.5 million a year to continue its work.