You are right, if you break the waiver you fail even if the rocket lands 5 ft from the prefect or person doing the cert and is in perfect shape and everything worked as designed.

31K on a 54mm L? I would think that that would have to be a perfect rocket at the perfect time on a perfect day from a perfect launch site. John W what do you think? What kit or rocket is it?

Maybe it is just me be I would really like to see my cert and make sure everything works and keeping it close for recovery.

20k is a big hurdle, have you got lots of experience in high altitude flights? Do you have much experience with dual deployment and have a good track record? If you do not have DD down I would recommend a J to start then go big. It is a big jump to go from an I motor to an L.

I am not trying to talk you out of doing what you have in mind but safety is very important and if there is something you can do to be safer I hope you will do it. With all that is going on with the different agencies that over see our hobby we need to be even more vigilant in keeping the hobby safe and risks to a minimum. And I also think you want to do everything you can to get your rocket back in one piece.

Good luck, I will be there and hope to see it fly.

James offers good counsel on all the above. Yep, if you break the waiver, you fail the cert. Ditto if you land outside the cylinder of the waiver.

Regarding an L730 on a minimum diameter. That is theoretically doable, but it is a dicey shot. I've done several J570s on a 38mm rocket, but an L730 in a 54mm rocket would likely exceed M2 and it would be a safety issue that I personally would not feel comfy with. Should you lose a fin (very possible given the geometry of the rocket and the physics involved) you would be skywriting with a very dangerous rocket. Are you using a fin can, or did you mount the fins directly? Be *very* careful and consider using an away cell if you go this route. Make sure everyone on the flight line is 100% dialed in to what you are doing, just in case fast decisions must be made.

Regarding 31K on an L730. The current Tripoli L record is 31,316', and that was done on an L330 (not an L730). The L330's lower average thrust, 200 add'l NS, and longer burn make it a much better candidate for altitude than an L730. I've personally never heard of an L730 going much over 20K. You'd have to drop several lbs. of lead into it to get it up to optimal mass... and all that lead takes space, complicating other parts of the puzzle.

Everyone that knows me knows I'm all for pushing the envelope. An L730 in a minimum diameter rocket for an L2 cert is pushing the envelope in a number of directions. I'll help you if I can, but I suggest walking before sprinting 😯 If you didn't use a fin can, you'd better have at least 3-5 layers of glass and/or carbon over the fins and the airframe better be filament wound glass or carbon. The rocket needs to be as short as possible (say 55" or less?), you'd better be undeniably certain of the CG/CP, and you need to have the cone pinned very, very, very securely into place.

Have you thought of trying a K550 or something similar first?

Sorry for the long reply. We all want a safe flight.

J

I'm a little concerned because others flying the same rocket on the same motor said they hit 31K? Thoughts?

Rockets are like Fish.... thier stories are bigger than they are. 😆

Like James said, Cert with "J" Motor first. Then do the "L".
You will have plenty of time to destroy your Rocket, after your Cert. 😆

Have you thought of trying a K550 or something similar first?
J

John, it is his L2, I would think the largest motor he has used is an I unless working with someone on a group project. Or he was certified some time ago and had let it laps.

sserell, I also would be willing to help if I can. Both John and I are TRA TAP members have done numerous certifications at all levels. NCR does not have any rules that say that you need to do your L1 on an H motor and your L2 on a J but it there are two motor classifications and L2 has 3, you should work through them and learn as you go. Trying to go to fast can be risky and you may learn the hard way and that can increase the risk for spectators.

Go slow, the hobby is not going anywere.

Like James said, Cert with "J" Motor first. Then do the "L".
You will have plenty of time to destroy your Rocket, after your Cert. 😆

K's are great too. there are a few K's out there that are fun!

Indeed, James - you are right again! I had said K550... a J415 has a lot of snort and if someone did an L2 on a full J that is minimum diameter, that is cool. There are some great 54mm J's that would be a nice test.

Remember, the LCO has to sign off on this -- and his word is final. If the LCO deems the flight, the rocket/motor combo, the conditions, or the rocket itself unsuitable, then it can't fly. If someone came up with an I motor in an Alpha, it probably wouldn't be allowed to fly. Same rationale may come into play here. We have great LCOs, and we must defer to their judgment.

JW

Actually, it comes down to the RSO's (GOD on the range) decision. And everything advice wise offered has been excellant counsel. Costly mistakes happen with a GO attitude and inexperience or lack thereof.

I'm a big fan of MD rockets... specifically have a 54mm bird designed around the L330 and currently down to 54" although I have a new Von Karmen nose for it and haven't measured it with that nose yet. Sims to just shy of 32K on the L330 and I'm trying to figure out how to squeak another 3" out of it... got Tripoli clearance, got the motor (one - perhaps the last of the Ellis L330's) and am aiming for the TRA L record... perfect conditions must apply.

In any event, don't believe much of what you see from Rocksim aside from CP and CG calcs... Good luck to all seeking records.

Warren

In any event, don't believe much of what you see from Rocksim aside from CP and CG calcs... Good luck to all seeking records.
Warren

And you need to keep in mind that both are dynamic.

Thanks for the feedback. I think I'll go with a small J to cert and then step up to the big stuff. I was concerned about the waiver because as Warren mentioned Rocksim doesn't always sim perfect, esp when you're pushing the envelope.
Someone asked - the kit is a Mongoose from Performance Rocketry - all CF with a high temp really great epoxy. Can't wait to fly it.
The 31k on an L730 - don't know thats just what someone reported and they new it would be close to the TRA record but didn't submit it. All I know is just because somethings a record doesn't necessarily mean it can't be shattered - look at Delius and his new M record! Pretty impressive.
Anyhow even if its sims to 19,500 should I try to get a waiver for higher altitude to avoid possibly violating the 20k waiver when I fly it on an L? I don't want to get the club in trouble with the FAA and thought it better to be safe. -Sean

if you are prediction that close to the waiver you should fly when the windows are open to avoid any problems.

Good choice on going with the smaller motor. What is the biggest motor that you have flown? what is your dual deploy experience?

We *may* have a higher window in July, see Joe Hinton for the details. If we do, I'm going to fly the rocket on the home page of this site to see if I can increment my current personal best.

BTW, it was Curt Von Delius who flew the L record. He is an amazing flyer.

Great call on going with the J first! I really think that is the best way to go.

JW

Curt is the guy from "up over" right? Is so I spend some time talking to him at LDRS about some of his flights and looked at photo's and discussed his airframe and fins used. FYI, he uses Kelly Composites for his fins and then rolls his own airframe.

Yep, if you break the waiver, you fail the cert.

Not to mention that Joe Hinton, who is responsible for us staying under the waiver, will kick your butt. At only 5'7", I take that seriously. Plus, you don't want to jeopardize the fun of all. This is a very good question and good of you to bring it up. Welcome! You've gotten the best advice from the best. Just travel up the alphabet and enjoy the journey. As with J350's, K550's are some of my favorite motors. James is right, the hobby isn't going anywhere. There's time. Enjoy!