Prince William has come under fire for landing an RAF helicopter in the garden of his girlfriend Kate Middleton's home.

He reportedly asked Miss Middleton's parents' permission to land at their home in Berkshire because of a shortage of landing spaces in neighbouring Hampshire.

The Prince was criticised for flying himself and brother Prince William to a stag party in a Chinook helicopter last week.

The Ministry of Defence (MoD) defended his latest flight, saying it was part of a two-hour training session authorised as part of William's four-month RAF attachment.

The MoD said in a statement: "Battlefield helicopter crews routinely practise landing in fields and confined spaces away from their airfields as a vital part of their training for operations.

"These highly-honed skills are used daily in conflict zones such as Iraq and Afghanistan.

"Opportunities to use alternatives are therefore regularly seized. The aircraft landed in the field, after taking all necessary safety precautions, and was on the ground for 20 seconds.

"No one got on or off the aircraft. This was very much a routine training sortie that achieved essential training objectives."

William, the fourth successive generation of the monarchy to become an RAF pilot, received his Royal Air Force wings from his father Prince Charles on April 11 in a ceremony attended by Miss Middleton.

Known as Flying Officer William Wales, he is due to start an attachment to the Royal Navy in June.

© Independent Television News Limited 2009. All rights reserved.