L3 practice launch, or not?

I would like to ask the opinion of the group: When you finish your level 3 rocket, what are the advantages and disadvantages of making a test flight before the certification attempt? Presumably the test flight would be on an L motor (and the rocket is capable of being safely launched on said L motor).

My inclination is to go ahead and make the first flight with the M. It isn't much more expensive, and if it doesn't work, I just try again with another M. If it does work, I get my cert. If the rocket gets destroyed, that's probably just as likely with an L or an M. The rocket is built extra-sturdy, so an M isn't going to shred it. The most likely failure modes would be a recovery failure or a motor CATO, I think.

What do you more experienced guys think?

-- David

Reply to
David
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I agree with you. That's what I figured when I did mine & it worked out fine.

Good luck.

Reply to
Phil Stein

I would recommend going ahead and flying with the M motor. 90% of the failures are recovery. This is just as likely with an L as with the M.

Tom

Reply to
Tom Binford

It's up to you, but if you do an "L" flight first you can prove out the systems before the "hey everybody watch this" effect of a cert attempt is involved.

(And if you use an Aerotech 75/5120 motor, you might be able to find some of the original L1120-labeled reloads, so you can do nearly-identical "L" and "M" flights! :)

-dave w

Reply to
David Weinshenker

David, It depends on your design and weight. If you are doing a standard design rocket and you have several larger rockets successfully built and flown, go for it full up M. on the other hand if you have an exotic design, such as a saucer or pyramid of death, maybe a test flight on a smaller K or L motor is something to consider, providing the weight of the rocket will allow for a simulation, indicating a possible successful flight on a lesser motor. You did not indicate if you are doing TRA or NAR L3. However, whichever L3 process you are using, talk to you LC3 if NAR, or your TAP if TRA. If you want and you use RockSim, send me you RockSim file and I'll give you a opinion via private email.

Fred Wallace

5763, TAP
Reply to
W. E.Fred Wallace

I agree.

I would restate the question as "should I have a spare rocket"?

Of course!!

LOC Rocks.

Reply to
Jerry Irvine

Thank you for your input.

Reply to
Jerry Irvine

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Reply to
W. E.Fred Wallace

Fred said exactly what I was going to write and would like to see. I will add if you are test launching a non standard design to ballast it to the same CG as the M (or larger) motor. May require TAIL weight! I test flew my L-3 on an O motor at a non TRA-NAR launch then used a 6000ns M for the cert.

Mark TAP,..... and other thankless positions

Reply to
Mark Clark

Do your cert flight. If you encounter a problem, you encounter a problem. There's a slight chance that a repair of a damaged and documented bird come under scrutiny.

If it's ready, do it!!! :-)>

Reply to
Gene

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