Fighter jets have rehearsed a fly-past over Anglesey for the Diamond Jubilee, although the actual event will be over Windsor Castle.
More than 200 spectators watched Hawk, Tornado and Hercules planes take to the skies on Tuesday at Mona Airfield.
Pilots had to pretend it was the Queen’s residence in Berkshire.
On Saturday, 80 aircraft will take place in the real fly-past, which is part of the celebrations to mark the Queen’s 60-year reign.
RAF Flt Lt Rob Pitt told BBC Wales the pilots taking part were highly skilled, and the level of complexity was “very, very high”.
“The Royal Air Force train the absolute best combat fast jet pilots in the world and all of those combat fast jet pilots come through Royal Air Force Valley to do that training,” he added.
“So they’ve been training for this with the commanding officer for quite some time. I think today is going to bear the fruit of those efforts.”
RAF squadron leader Albie Fox said the 80 aircraft would be simulating the Battle of Britain on Saturday.
“This is one of the more complex fly-pasts there have been because there are so many aircrafts taking part,” he added.
“It is quite complex and it takes a lot of choreography to make sure it happens correctly.”
The Duke of Cambridge is based at RAF Valley, where he is a search and rescue helicopter pilot.
Sourced by BBC