Prince William learnt to fly earlier this year
Prince William is to train as a full-time pilot with the RAF Search and Rescue Force, Clarence House has said.
William, who learned to fly with the RAF earlier this year, said he wanted to "serve operationally".
The prince is an officer in the Household Cavalry Regiment and has also spent time with the Navy and Army.
He said he wanted to build on his experience "especially because, for good reasons, I was not able to deploy to Afghanistan this year".
He added: "It has been a real privilege to have spent the past year understanding and experiencing all aspects of the British Armed Forces.
"I now want to build on the experience and training I have received to serve operationally."
William undertook a shortened training course - less than four months compared with the usual four years - and was awarded his wings by his father Prince Charles in April.
The time I spent with the RAF earlier this year made me realise how much I love flying
His first solo flight came just eight days into his RAF training, when he piloted a propeller-driven Grob 115 E light aircraft round the airfield at RAF Cranwell.
He then trained on the faster Tucano T1 plane at RAF Linton-on-Ouse in North Yorkshire.
His final placement was at RAF Shawbury, Shropshire, where he learnt to fly the Squirrel helicopter.
Announcing his plans, the prince said: "The time I spent with the RAF earlier this year made me realise how much I love flying.
"Joining Search and Rescue is a perfect opportunity for me to serve in the Forces operationally, while contributing to a vital part of the country's emergency services."
He will begin 18 months of search and rescue training in January and continue his charitable and royal duties until then, Clarence House said.
He could be flying operationally in 2010 at one of six UK-based RAF Sarf units.
During his training he was criticised for landing a military helicopter in a field belonging to his girlfriend Kate Middleton's family in Berkshire.
At the time, the Ministry of Defence said the landing was fully authorised as part of the prince's attachment to the RAF.