Got all my bills paid early, and had just a bit left over. Went back to Hobby Lobby and bought a set of whistling rockets. Found some interesting stuff...
The head and fins are foam. The body is wrapped with a vinyl sticker. Looks like the fins are glued onto the wrap with hot glue or epoxy. The body, finger pulls, and the "hooks" are plastic.
I grabbed the finger pull and twisted. Was able to pull it out fairly easily.
The body tube is hard translucent plastic.
This is how the whistling head is attached...
It's kind of a "good news/ bad news" sort of deal. The body tube ID is too small for 18mm engines. 14mm will fit fine with centering rings. It looks like it *might* be possible to transplant the head onto BT20 stock, if I can tease the head out of the plastic tube. I have no problem flying this on a 13mm engine. I don't know if I will just spit the engine (they're really light), or try to build a motor mount with streamer/whatever. I also have no problem letting the plastic body with the foam-covered head free fall back. Obviously, it's going to arc over and come in nose first. Before you take that deep breath to start yelling at me, that's exactly what these things are designed to do. Label on the package says "flys to 150 feet". I don't know if a 13mm motor will carry it any higher, but I doubt there would be any significant increase in terminal velocity over the rubber band powered flights.
It's snowing and really, really cold outside right now or I would try one of these out with the rubber band. Nope for tomorrow. In fact, pencil out all of next week...