The Thunderbirds Diamond at the Chicago Air Show 2001

It's not normal to see the Thunderbirds from this head-on angle, because airshow regulations generally prohibit a group of aircraft (or even single aircraft) from flying directly over a crowd, in order to reduce the probability of an accident.   But I was able to get these shots because my vantage point at the end of Fullerton Street jutted out into Lake Michigan quite a bit further than the official "show center" line at North Beach.

The original Thunderbirds consisted of a four plane team flying in a classic "diamond" formation.   This is still the basis of the team demonstration today.