Flyte is an old Magykal power which can only be used when one is in possesion of the true flight charm. The true charm was crafted using the golden threads from the spiders of Aurum. To activate this ability, one must hold the charm and picture themselves in Flyte to truely Flye.
Simon Heap restored the long lost charm during of Flyte (book) with the help of Hugh Fox, the Chief Hermatic Scribe at the time. However, the charm did not work properly for Simon, as it was incomplete. When Septimus Heap aquired the charm, he held it in his hand and to his amazement found that it bonded with his charm that Marcia Overstrand had given him during Magyk (book). He was in posession of the Flyte charm until Marcellus Pye took the charm from him, claiming to be its rightful owner. Septimus regained the Flyte Charm when Marcellus gave it back to him in a golden box in return for the Potion of Eternal Youth the Septimus crafted for him. Since this event, Marcia has consfiscated it multiple times.