Comments
29mm inside adapter in 38mm mount. CATO at ignition. Rocket lifted three feet up rail and slid back down. Forward half of airframe did not separate from back end. No flame visible out the back, no burning grain observed, no evidence of extended burning inside the airframe.
Forward closure and front of adapter were torn free and embedded in dog barf inside airframe. Motor casing kicked out rear of rocket. Rest of adapter remained in rocket. Recovered all parts of the motor except the rear grain (despite extensive search by several people around the pad). O-rings were all in place, forward insulator was still inside airframe as well. No “leftover” parts found at table where I assembled motor, checklist was checked off at each step. No issue threading closures at assembly.
Ejection cap was still in place on forward closure, powder inside. The threads on the closure and casing forward end appeared fine. Delay appeared not to have ignited at all, although delay spacer had some charring. Forward grain appears to have burned along c-slot and around/under the grain casing. The front end of the liner was heavily damaged but the rear part of the liner was relatively intact. The motor casing had a large gouge on the aft closure and the casing bulged at the aft end, likely from the impact that gouged the aft closure. Unable to unscrew the aft closure due to the damage.
On-field discussion suggested that the igniter might have gotten caught and not pushed out of the motor as it lit, causing an overpressure situation. I used the supplied igniter from the reload pack.
