Hi Bob I could be wrong on this but another member here on the forum indicated that TRA has sent out a notice to all their prefects that air starts on anything J or larger has to be more than just a timer. Hopefully somebody will chime in and clarify. I do not believe this is a rule yet however LDRS may also go by the new suggestions for safety. I do have a question into the L DRS section with the request for clarification of this.
Nick,
There is no rule restricting timer usage for staging rockets nor was there a notice sent to the prefects. While the Tripoli Board of Directors did indeed discuss this at length, our conclusion was that flyer education would be a better venue than rule making.
Take launch rods for example. Years ago, virtually every high power rocket has a big launch lug on the side. Then along came rail buttons. Flyers soon learned the advantages of flying off of rails which included no more rod whip and less aerodynamic drag on the airframe. Over the past few years the usage of large rods has almost dried up because we, as a hobby, found a better way.
Think of timers as "electronic launch rods". While timers work, there are many ways of igniting the sustainer while really increasing safety at the launch site.
The biggest argument I hear against using one of these smart altimeters is cost. Folks don't want to pony up extra cash even if deep down inside they may agree that using one is a better way. Let's face it, high power rocketry is expensive. Staged rocketry is like twice as expensive. We've all seen the video of the scary two stage flight that started this whole discussion. Had the flyer spent the $69 for the altimeter it would have not ignited the $65 sustainer motor and the flight would still have been ugly but would not have been nearly as dangerous. Net delta $4!
At my range, every once and a while someone will show up with a high power rocket that has 1/2" launch lugs on it. When I question the flyer about them I normally get "Well, I'm old school!" Folks, my translation of that statement falls into one of two categories. One, "I've had this rocket a long time and I'm too cheap or lazy to put rail buttons on it." or two, "I know there are better ways but I don't care about safety."
Don't go "old school" with staging electronics. Your safety and the safety of the folks around you should be very important to you.
Bob Brown
Vice President, Tripoli Rocketry Association
Prefect, Kloudbusters Rocket Club,
High Power Flyer