Originally Posted by MarkB.

For those unfamiliar:

The failure mode on the 18mm X-15 was ballistic recovery. The engine was positively retained by the plastic retainer, but was very loosely held in place and the ejection charge was vented around the engine rather than pushing out the parachute. Keep in mind that it's a relatively heavy injection-molded RTF. It also needed at least a half ounce of clay up front as it was, to paraphrase GH, unpredictable, off the pad.

It didn't come with clay and it needed a proper engine mount.

The rocket was subject of a consumer recall. - if you sent it back to Estes, they'd send you some plastic flying saucer. I just kept mine and flew it around the house making whoosing noises when no one's around.

Supposedly, a Cub Scout got hit by one that penetrated his torso under his arm pit and had to have it surgically removed. Not Estes' finest hour. . . .