Britain's Prince William (L) smiles as he walks with his girlfriend Kate Middleton at RAF Cranwell, central England April 11, 2008.

Prince William graduated as a Royal Air Force pilot Friday after successfully completing an intensive flying course.

The prince, 25, received his wings from his father Prince Charles in a graduation ceremony at the RAF Cranwell air base in Lincolnshire.

A smiling Charles spoke to his son as he stuck on the wings badge and shook hands with him afterwards.

William, second in line to the throne, temporarily left his army officer role for a specially slimmed-down four-month RAF course, aimed at preparing him for his future duties as head of the armed forces when he becomes king.

He learnt how to fly propeller-powered planes and helicopters and is the fourth generation of British royals to become an RAF pilot.

The prince's girlfriend Kate Middleton was among his guests. Charles's second wife Camilla, Duchess of Cornwall, and Lady Sarah McCorquodale -- the sister of William's mother Diana, princess of Wales -- also attended.

Air Chief Marshal Glenn Torpy told the graduates: "This is probably one of the most significant milestones in an aviator's career. It's something that not many people can do and you should be very proud of what you have done."

Middleton's appearance at William's graduation ceremony at Sandhurst military academy in December 2006 helped build the expectation that the couple, who have dated since 2003, when they were both students at St. Andrews University in Scotland, were headed for marriage.

An April 2007 report that the pair had split up seemed to pour cold water on the fevered speculation.

Their appearance together prompted bookmakers William Hill to cut their odds on a 2008 engagement from 2-1 to evens.

(Agencies)