In January 2009, William transferred his commission to the RAF and was promoted to Flight Lieutenant.
He trained to become a helicopter pilot with the RAF's Search and Rescue Force.
In January 2010, he graduated from the Defence Helicopter Flying School at RAF Shawbury.
On 26 January 2010, he transferred to the Search and Rescue Training Unit at RAF Valley, Anglesey, to receive training on the Sea King search and rescue helicopter; he graduated in September 2010.
This made him the first member of the British royal family since Henry VII to live in Wales.

William's first rescue mission as co-pilot of an RAF Sea King was a response to an emergency call from Liverpool Coastguard on 2 October 2010.
In November 2011, he participated in a search-and-rescue mission involving a cargo ship that was sinking in the Irish Sea; William, as a co-pilot, helped rescue two sailors.

William was deployed to the Falkland Islands for a six-week tour with No.
1564 Flight from February to March 2012.
The Argentine government condemned the Duke's deployment to the islands close to the 30th anniversary of the beginning of the Falklands War as a "provocative act".

In June 2012 Prince William gained a qualification to be captain or pilot in command of a Sea King rather than a co-pilot.
His active service as an RAF search-and-rescue pilot ended in September 2013.
In January 2009, William transferred his commission to the RAF and was promoted to Flight Lieutenant. He trained to become a helicopter pilot with the RAF's Search and Rescue Force. In January 2010, he graduated from the Defence Helicopter Flying School at RAF Shawbury. On 26 January 2010, he transferred to the Search and Rescue Training Unit at RAF Valley, Anglesey, to receive training on the Sea King search and rescue helicopter; he graduated in September 2010. This made him the first member of the British royal family since Henry VII to live in Wales.
William's first rescue mission as co-pilot of an RAF Sea King was a response to an emergency call from Liverpool Coastguard on 2 October 2010. In November 2011, he participated in a search-and-rescue mission involving a cargo ship that was sinking in the Irish Sea; William, as a co-pilot, helped rescue two sailors.
William was deployed to the Falkland Islands for a six-week tour with No. 1564 Flight from February to March 2012. The Argentine government condemned the Duke's deployment to the islands close to the 30th anniversary of the beginning of the Falklands War as a "provocative act".
In June 2012 Prince William gained a qualification to be captain or pilot in command of a Sea King rather than a co-pilot. His active service as an RAF search-and-rescue pilot ended in September 2013.
Prince William, Duke of Cambridge