Leader Pale Ale, a tribute to the iconic Lancaster Bomber of the Royal Air Force Battle of Britain Memorial Flight based at RAF Coningsby, PA474is one of only two airworthy Lancasters that exist today of the 7377 aircraft built. The current 460 Sqn RAAF: 'Leader' livery serves as a living memorial that commemorates the monumental sacrifice of those who served in Bomber Command. Lest We Forget.