London - Within hours of graduating as a pilot from Britain's Royal Air Force (RAF), Prince William used a helicopter training exercise to fly himself to a party, picking up his younger brother Harry in London on the way.

The Ministry of Defence (MoD) Tuesday revealed details of the actions of 25-year-old William, saying that the sortie was always planned as a finale of his four-month air force training.

William, a serving officer in the British Army, undertook the trip after receiving his wings as an RAF pilot during a ceremony in Lincolnshire, on the east coast of Britain Friday.

He piloted a Chinook helicopter to London, picked up Harry, 23, and proceeded to fly to a stag party for Peter Phillips, the son of Princess Anne, on the Isle of Wight, off the south coast of Britain.

The training flight included all the test elements of flying in busy air traffic over London, crossing water and landing in an enclosed helicopter pad, the MoD said.

"Flying at low level Prince William piloted the heavy support RAF Chinook helicopter through the busy London flying lanes to a helicopter landing site in central London before departing the lanes to the South West, making a water crossing and an approach to a civilian airfield routinely used by Chinook squadrons," said the statement.

William's instructor, who was not named, reportedly said: "Prince William showed natural piloting skills and an ability to pick things up quickly."