Straight from AeroTech:

"AeroTech DMS™ Motor Thrust Ring Advisory

It has come to our attention that there have been two (2) recently reported instances of the factory glued-on thrust rings of high power (H-class and larger) DMS Disposable Motor System single-use rocket motors breaking off the motor casing during flight. This usually results in the bare motor flying through the rocket and into the air, often in an unstable and unpredictable manner.

Customers are advised to examine the strength of the glued-on thrust rings on their DMS motors before flight, and take one or more of the following steps to mitigate this problem:

1. Apply a generous amount of CA (cyanoacrylate) glue to the forward bulkhead side of the thrust ring/motor casing interface. Allow the CA to thoroughly penetrate the space between the ring and case, soak into the ring and allow it to solidify completely before use.

2. Tightly wrap a layer of 3/8” wide or wider masking tape around the motor case immediately adjacent to the thrust ring, to a thickness of 1/16”.

3. Remove the glued-on thrust ring and tightly wrap a layer of 3/4” wide masking tape around the motor case, flush with the nozzle end of the case, to a thickness of 1/16”.

4. Use a motor block within the motor mount tube that will transfer the thrust of the motor to the airframe and prevent the forward movement of the motor within the tube.

AeroTech is continuing to examine and evaluate the situation and will take appropriate action on modifying new production shortly.

Your understanding and patience is appreciated!"