The G-91T advanced jet trainer was based on the G-91R and gained both length and wingspan on the original. It maintained the single-seater's characteristics and kept an acceptable range. MM6344 actually flew as SA-44 with the Scuola Volo Basico Avanzato Aviogetti at Amendola.
The G.91Y was considerably superior to the earlier versions in almost every aspect. The most noticeable difference are the two J85 engines that replaced the single Bristol Orpheus but there were many more improvements. This one flew for many years with the 101°Gruppo CBR/8°Stormo, of which it displays the symbols on nose and tail respectively.
In the PAN version of the G.91, the guns have been replaced by counterweights, and pitch dampers and the smoke system have been added, all especially for use by the 313° Gruppo Addestramento Acrobatico, better known as the "Frecce Tricolori".