Squid launching from the water had been reported by sailors for centuries and dismissed as brief accidental leaps. A photographic sequence taken in the North Pacific and analysed by Jun Yamamoto and colleagues in 2013 established that the animals do more than jump.
The sequence shows a distinct set of phases. The squid jets hard to break the surface, continues to expel water while airborne, then spreads its fins and the membranes between its arms into two lifting surfaces and adopts a glide posture. Before re-entry it folds the fins back. Estimated ground speeds of over ten metres per second and glide distances of a few tens of metres were derived from the imagery.
Whether this counts as flight depends on definition: there is no flapping, and the trajectory is ballistic with lift, so gliding is the appropriate word. The function is likely escape from predators such as tuna, though energy saving during migration has also been proposed. The number of squid species that do this, and how often, remains poorly quantified because the events are brief and hard to observe.