[quote=deefer dog;9113858]
Indeed sky9, density altitude DOES affect all aircraft, fast jets included. Although perhaps not an issue in this accident, the fact remains that as the density altitude increases, so too does TAS relative to IAS. QUOTE]
Sure it would make a bigger circle if the TAS was greater, but as any display pilot would tell you - one never aims for a round loop if one starts from a low level. It just is not the safe way to do it in a display.
Except, of course, all competition aerobatic pilots......
It's a bit silly to make generalisations, as we regularly see square loops at quite low levels in displays.