Hawks were allowed in, someone pointed out that the dead sparrows fly the same aircraft. some good photos here if you're interested:
100Years Navy plus Lusty in London 9th May 09
and
Lusty Sunday
100 Years FLY NAVY Greenwich 10th May 2009
and
Fly Navy 100 090509, another take
in fact just go to..
Modern Military Photography • UK Airshow Review Message Board
and look for the london threads .