The article says:
Later we read:''Moreover, they found, the glider worked. More than two millennia after its construction, it still sailed easily through the air at only the slightest flick of the hand.''
Later still, we read''The model makes a perfect glider as it is. Even though over 2,000 years old, it will soar a considerable distance with only a slight jerk of the hand''
A little biased then? If it's a model airplane, it glides perfectly for a considerable distance, but if it's a model bird, it would (erm obviously to the author) be ''hurled through the air'' and would not glide? Hmm'' It is also possible that the artifact served as a child's toy, though its design would not allow it to glide like a bird if hurled through the air.''
Replicas of the throw sticks found in Tutankhamun's tomb were found to return like boomerangs, so the AE knew something of designing objects for flight of sorts.
Here's a couple of examples.
I would expect the standard of workmanship to be higher if this was carved by a craftsman, as they were highly skilled, so this artifact looks like either an unskilled adult's attempt, or a child's version IMHO.
I haven't read enough about the subject matter really though, and hopefully readers here would not be satisfied with that article linked to above, in isolation.
Nebankh