Skells are pilotable mechs. They can run, drive, and fly. They're Transformable and that means that if something falls off, the transformation can no longer happen correctly. Why would you pilot something that can no longer perform properly if it get's damaged?
Skells can fly, if a module get's slapped to them. This equates to rockets stuck to their shoulders. When they do fly, do they have wings? If the flimsy looking flaps count as wings then yes, but on the crazy scale they are about half way.
A Skell won't directly try to kill you, but flying without good wings, and fear of death via damage when trying to transform launches a Skell to 4th.
Next up, we find out way back to Azeroth, hopefully not flying using a Skell -- because the next WoW mount might cause some damage.