Rocket bike stunt was dangerous

By The Standard Staff - 08/15/2007

I was disappointed to see the name of the National Association of Rocketry in the story about C.J. “Turbo” Turner in the Standard during Evel Knievel Days. I am proud to belong to this organization and serve as senior adviser to the NAR Montana Section. NAR was created in 1958 because people were experimenting (unsafely and unsuccessfully) with rockets following the launch of Sputnik and the beginning of the space race.

The founders of NAR wanted to provide a safe alternative for people wanting to learn about rocketry. Their every effort since then has been to promote this hobby safely. They have worked with the Tripoli Rocketry Association, National Fire Protection Agency, and the Consumer Protection Safety Council to create official safety codes to ensure safe rocketry activities.

Although I cannot speak for the national organization, I can tell you as an officer of NAR Montana that the kind of stunt that Turner promotes completely disregards some of the most basic tenets of our safety code, particularly the safe standoff distance for participants and spectators. This rule was created in order to prevent injury caused by a motor failure.

For a complex rocket, a rocket with more than a single motor installed with motors of the impulse used by Turner, the safe standoff distance is 300 feet. That means that Turner and all spectators should be at least that far away when he ignites his motors.

Also, because the safety code requires that we launch rockets nearly vertical, the motors that we use to propel our rockets are designed to fail axially, not radially. That means that when the occasional failure does happen, the motor bursts toward the two ends of the motor, usually spitting out the nozzle and rear closure toward the ground and the bulkhead straight up.

If that were to happen to Turner, the hot bulkhead could strike him in the back or the head. The hot nozzle and rear closure could fly with great force down the street, free to strike someone hoping to snap a picture. The burning fuel grains would probably be extinguished by the immediate loss of pressure, but they might also throw burning propellant in any direction. That fuel is very difficult to put out as it contains its own oxidizer.

Third, the motors that Turner is using are legally classified as Class B explosive, as is gun powder, but NAR and TRA have been suing for several years to have that classification overturned. Ammonium Perchlorate Composite Propellant has been engineered to function by burning at a very controlled rate. Boasting about explosives and being crazy enough to strap them to his back in order to promote this stunt harms the hobby.

Fourth, using solid propellant is just stupid. Others have mounted hybrid or peroxide rockets to bikes. The advantage is that they can be instantly shut off if something happens. Those types of rocket motors are used with a deadman switch so that releasing the grip shuts off the motor. If Turner falls off his bike it will spin around wildly and uncontrollably, shooting very hot exhaust gases in every direction. I don’t believe he has adequately analyzed that failure mode.

For the reasons above, Turner is doing a stunt that is irresponsible and unsafe to himself and the unsuspecting spectators. Unfortunately it also damages the reputation of true rocketeers, like the members of our club who get together monthly to learn about rocketry and to launch responsibly. We study aerodynamics, control systems, propulsion, craftsmanship, and composite materials in pursuit of our hobby.

Since the beginning of NAR there has never been a serious accident or injury to a NAR member while following the safety codes. To see a copy of the High Power Rocketry Safety Code go to http://www.nar.org/NARhpsc.html. Our club web site is at www.bigskyrocketry.org. Our launches are currently suspended due to fire restrictions, but we hope to resume later this month or September.

— Steve Shannon lives at 3427 Hannibal St. in Butte.