Not a bird, not a plane ...

... not a butterfly, not a moth. It is a caddisfly, one of the Trichoptera.

^{Olympus Stylus 1s, 42mm, ISO160, f5.6, 1/160s}

Many larvae of caddisflies are aquatic and dress themselves: they use silk to make protective cases of gravel, sand, twigs, and other things they find, and can look like this:

^{Photo by Kristian Peters, from Wikimedia Commons, under a CC BY-SA 3.0 license}

Or this:

^{Photo by Ashley Pond, from Wikimedia Commons, under a CC BY-SA 2.5 license}

Not the prettiest of flying insects, but the larvae are quite interesting.