The Delta Formation creates a letter D, starting with three airplanes up front in Line Abreast position. Row two consists out of two aircraft flying Line Abreast and the fifth plane flies behind them, on its own. It is possible to fly the Delta Formation with five aircraft only, as you can see in the top right image.
In Delta Formation, each row of planes flies a little lower than the row in front of it. This ensures that the planes do not fly into each others propwash (air that is disrupted by a plane’s propeller).
The Delta Formation is a very wide formation. Therefore, watching the formation turn in Delta is spectacular to watch. The formation is very manoeuvrable, making it easy to do lazy eights.