Question about TARC rules

Hey guys,

It looks like I'll get to mentor a local TARC team and I had a question. In the rulebook it mentions that all guidance upon liftoff must be at least 6' long and 1/4" in diameter. The team members I talked to said their rocket is about 2.5' long and is going to fly C6 to D12 (I'm a bit nervous on that one). I'm a bit afraid that there's a bit of overkill with this launcher, do I have anything to be concerned with? Am I going to have to build a nice PVC pad for this?

Thanks,
Jason

Down in High Meadows, VA at the finals, they have a 6 foot 1/4 inch rod. We have usually used a 4 or 5 foot rod when testing and while making our qualifying flights. Does the rocket have a quick or slow accelleration? If it is quick, you should be fine. With a c6 booster, you may be a little slow off the pad. All that means if you make it to VA, your rocket will be more stable coming off the pad. But no, it is not required to have a 6 foot rod when flying, it is just the reccomended. You can also use any of your own equipment down in VA.

Originally posted by jetra2
. The team members I talked to said their rocket is about 2.5' long and is going to fly C6 to D12 (I'm a bit nervous on that one).

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Me too - is there a reason they not using the D12 as the booster?

Hi Jason:
You should ask rule interpretation questions over on the https://groups.yahoo.com/group/NARTARC/ forum as you'll get an official interpretation from Trip Barber.

Take a look at https://groups.yahoo.com/group/NARTARC/message/3891 for the answer to your launch rod question.

Originally posted by runandgun13
You can also use any of your own equipment down in VA.

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Provided it is at least the equivalent of a 1/4" diameter, 6' long rod, and is approved by the officials.

Will M also gives good advice--use our forum to get reliable rules interpretations.

--tc
TARC forum moderator

Originally posted by runandgun13
Down in High Meadows, VA at the finals, they have a 6 foot 1/4 inch rod. We have usually used a 4 or 5 foot rod when testing and while making our qualifying flights. Does the rocket have a quick or slow accelleration? If it is quick, you should be fine. With a c6 booster, you may be a little slow off the pad. All that means if you make it to VA, your rocket will be more stable coming off the pad. But no, it is not required to have a 6 foot rod when flying, it is just the reccomended. You can also use any of your own equipment down in VA.

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All TARC mentors and competitors need to read the rule book and handbook before they launch their rocket. Rockets still have to meet NAR safety rules.

The following quotations specifically address the launch rod length and motor selection questions.

The 2007 TARC rules requires "at least 6 feet of rigid guidance, including use of a rod diameter of at least 1/4 inch, if a rod is used."

https://www.aia-aerospace.org/aianews/features/team_america/pdf/2007_rules.pdf

Additionally, the rocket must use a motor or combination of motors such that "... the motor(s) you pick provide enough thrust to give your size/weight rocket a speed of 40 ft/sec or so by the time it reaches the end of its launcher, so that it does not "stagger" slowly into the air and tip over and fly non-vertically if there is any wind. Generally, you need a motor or combination of motors whose combined average thrust is at least five times the rocket liftoff weight. As a rule of thumb, make sure that the model's motors' combined average thrust (in units of Newtons, which is how these are marked on the engine casing) is at least 25 times the rocket's liftoff weight in units of pounds."

https://www.aia-aerospace.org/aianews/features/team_america/pdf/2007_handbook.pdf

Bob Krech
MA TARC mentor