Helicopter failed to open. Rocket fell straight down and buried about a foot in the ground. Believe they have a design issues where the helicopter blades lock into the side of the rocket and prevent them from opening. Couldn’t open the blade a before the launch but incorrectly figured the force of the engine would open when it reached top of flight. Estes has been very difficult to work with since I have tried under warranty. Lately had to send them pictures of the rocket but still don’t have a reply. The failure is a design issue.