I have come across this numerous times when using a parachute with a model rocket. When the nose cone pops after the pressure has built up in the main tube forcing the parachute to deploy, the suspension lines become tangled up causing the the parachute to not deploy correctly. A spacer has been added to the suspension lines that when the parachute catches the first bit of air, the spacer will slide down that suspension lines thus keeping the suspension lines free from entanglement. This is due to upward for of the airpressure filling the parachute and the downward motion of gravity pulling the rocket to the ground. Another added feature that I will be adding and testing in the next few months are suspension tube guides along the leading edges of the parachute. What guides will accomplish is they will place a little weight on the leading edges of the parachute. When the chute catches the air the gravity will pull on the tubes due to their weighing more then the parachute does. As the parachute fills with airthe tubes will force the leading edge of the parachute to form a vase like shape thus catching more air and eleviating the possibility of a blow-out. A blow-out is when the dynamics of the parachute allow the air build up in the center of the parachute to escape out of one of side's causing the parachute to collapse. The tubes used are the launch tower guide tube that comes with every rocket model kit. One tube should be placed between each set of suspension line eyes equa distance from each other with the suspension line being ran through the tube.