Do composite propellant model rocket motors ever fail? How do they fail?
Occasionally (usually less than 1% of the time) a composite model rocket motor will fail. The most common failure mode of a single-use motor is a case failure, where the casing will split into two or more pieces upon ignition, usually caused by a defect in the case itself. Most of the time the propellant will extinguish itself when this happens! Other modes may include a low-pressure ignition due to improper initiator installation and, rarely, ejection charge failure. For reloadable motors, the most common failure mode is a burn-through of the forward closure, usually as a result of improper motor assembly.
