Helicopters & Flying Spinners
This is a very complex firework, partly in the construction but mostly in the physics. Flying spinners a.k.a. helicopters have to have their wings placed in the correct place and have to be balanced exactly, otherwise they will not work. If it is just perfect, the fuse will light the propellant/color compound which will spray the colored flames and sparks squeezeing the hot gasses out of the fuse hole which will propel the whole firework in circles, thus acting like a helicopter because of the plastic wing unit. When the propellant is all burnt and the flight comes to an end, the burst charge is ignited and the stars are blown out and ignited at the same time.