In "Mission to Domino", after the Trix destroy Red Fountain, the school's staff and students flee to Alfea on four Red Fountain aircrafts.
In "The Crown of Dreams", the Specialists arrive to Domino on a Red Fountain aircraft in time to help the Winx fight against the Snow Monster and the Ice monsters sent by the Trix. The ship fires at the monster before landing in front of the Royal Palace of Domino.
Sky later explains that, after Red Fountain was destroyed and the Specialists took refuge in Alfea, he spoke to Professor Palladium who told him Bloom was on Domino and opened a portal for him so he could go find Bloom. Once the mission of the Winx on Domino is complete and the monster is defeated, the Winx and the Specialists return to Magix on the aircraft and at the end of the episode, the Red Fountain aircraft passes through the portal.
A Red Fountain aircraft before passing through a portal
In "Storming Cloudtower", the Winx and the Specialists arrive at Alfea through the Red Fountain aircraft.
This class of aircraft appears to have been replaced by the Hawks, Owls and Crows after the Specialists returned to Red Fountain after the Trix were defeated.
Unlike later Red Fountain ships such as the Hawk and the Owl, this model of Red Fountain aircraft does not appear to be capable of traveling between planets through faster-than-light speed since it required Professor Palladium to open a portal to be able to go to Domino.