My 1/4 Scale Patriot Missile had been sitting on a shelf for over a year after the middle of the airframe blew up during deployment.  I don't know if the piston got jammed or if I used too much gun powder, but the last time I launched it the parachute came out through the side of the airframe.  Above is a picture of what is left of the original rocket along with the parts I will use to repair it.