Megascale Flight (5e Spell)
From D&D Wiki
|Casting time:||1 action|
You touch a willing creature. The target gains a flying speed of 600 feet for the duration. While the spell lasts, the creature can spend 1 minute, during which it can take no actions besides the Dash action, to fully power its flight. While the creature is flying at full power, it can reach speeds equivalent to approximately 5 times the speed of sound (1 mile/second) in the atmosphere, or 1 light-year per hour in vacuum. In this state, the only actions the can take are the dash action or to return to combat speed, which it can do as an action.
When the spell ends, the target falls if it is still aloft, unless it can stop the fall. Once the target has a minute or less of the spell remaining, it is mentally notified of how much time is remaining via a 60-second countdown.