New rules will restrict flying over the Duke and Duchess of Cambridge's Norfolk home, over security concerns.
The ban affects Sandringham House and Anmer Hall, which are part of the Queen's estate in the Norfolk village of Sandringham.
Sandringham House is the Queen's private home and where the Royal Family traditionally celebrate Christmas. It is also a commercial estate, with its museum and grounds open to visitors.
The Duke and Duchess of Cambridge moved to Anmer Hall last year with their children after he joined the East Anglian Air Ambulance as a pilot.
The regulation comes into force on 1 November for Anmer Hall and 1 December for Sandringham House.