Terminal velocity is the highest velocity attainable by an object as it falls through a fluid.
In order for a Franklin-type starship to achieve liftoff from a planet's surface, it must achieve terminal velocity to get the stabilizers to provide lift. In 2263 of the alternate reality, the crew of the USS Enterprise dropped the USS Franklin off of a cliff on Altamid in order to launch the ship. The Franklin reached terminal velocity moments before it would've crashed and successfully achieved liftoff. (Star Trek Beyond)