That piccie was taken at Duxford flying Legends...by the look of those planes in the pic...I'd say 2005 (Ah...just seen the date on the piccie !).
I've got a full breakdown of all the composite 'wings' that made that formation so I wont cheat and enter.
Amongst the planes you will often see in these balboa's at FL' are :- Buchon, Skyraider, Corsair, Mitchell, Fury, Spifire, Hurricane, Mustang, Yak, Kittyhawk, Tomahawk, Hawk, Thunderbolt, Catalina, Tigercat, Hellcat, Bearcat. And dont forget, 2005 was the year the SAAB B17A arrived on the flightline !.The Tigercat allways led the main formation until it was sold and went over the Pond
By the way, the noise generated from all those 'Planes...you didnt so much hear it as felt it !.
Roll on this years event.