I took advantage of a fairly still day to launch some rockets this weekend, while most of the flights were uneventful, the Big Daddy decided to put on a show... Loaded up with the same Aerotech E18 motor I flew at the Tripoli launch the weekend before, it decided to CATO just a few feet off the end of the rod.
When the motor blew,the nozzle & propellant (which self-extinguished) were ejected. Everything except the aft closure were recovered.
The image above is three consecutive frames from the video.
I believe the cause of the aft closure failure was due to it not being fully secured in place. The closure was done up tight, however I believe that the liner tube may have been a fraction longer than normal, causing the aft closure to not screw in completely thus only having a small portion of thread engaged. As the motor came up to full-pressure, it simply pushed the ass end out of the motor in a bright flash of light. Impressive flight for all the wrong reasons! Check out the video after the jump.