Mad fly (volo folle) is an acrobatic figure you can see here. 
In the comments in the following pictures 
http://www.ww2incolor.com/italian-forces/Savoia-Marchetti_SM.html
some of you thougnt to a bad flying discipline; in reality they were raising this acrobatic figure. Considering they were flying over Madrid in a war mission, actually they were demonstrating selfconfidence and air superiority.
DVX

Mad fly

The Arditi were the Italian assault troops of WWI, to understand the equivalent of German sturm-truppen or stoss-truppen. After the war many of them joined the fascism and the first squadristi, giving some of their symbols to the fascism: the black shirt, the black flames on collar and the dagger.
As you can see in this 1938 pic, the Arditi veterans section of Florence alone can show 7 gold medals and many silver and bronze... 
DVX

Veterans of WWI Arditi

Another pic of this acrobatic figure. DVX