Photo: BOB HULSE
The cool bit is that they are using the same "jet propulsion" system that they do underwater - the resolution is not great but I think the streamers coming out the back of the squid in the photo are the jets of water, firing them out of the sea like a rocket. (Quite literally like a water rocket.)
Air resistance is clearly less than water resistance and so it may not come as a surprise to find out that the squid can actually achieve a higher velocity in the air:
"Because they knew the intervals of time between each photo, O'Dor and his colleagues were able to estimate the squid's velocity and acceleration, and compare them with these values for squid in water. They found that the velocity in air while the squid were propelling themselves with the water jet was five times faster than than any measurements O'Dor had made for comparable squid species in water."
There still seems to be a bit of debate regarding the significance of the "flying" behaviour but first author Ronald O'Dor is convinced that it is normal squid behaviour. He even goes as far as to propose that they might be doing it routinely to save energy. Given the acceleration, I think it also fits the standard predator-avoidance explanation for other marine flyers. More research needed, so hopefully lots more flying squid pictures to come!