trying to understand how the rules work:)

Steve Shannon

Well-Known Member
TRF Supporter
Joined
Jul 23, 2011
Messages
8,495
Reaction score
6,923
Location
Butte, Montana
Exactly Fred, the TRA forum does have some very experienced flyers especially technically, but they aren't necessarily any better than the rest of us, and some are just as full of BS as some of the ones on TRF.
Yea - I'm not sure why Steve is thinking things are better at the TRA forum.
I find the volume much lower but with similar signal to noise.
It’s simple. The Tripoli Forum is the only place where an official answer, relative to Tripoli rules or procedures, will be provided.
 

MikeT

Well-Known Member
Joined
Aug 11, 2016
Messages
294
Reaction score
286
We're 4 pages in, and I haven't seen a single helpful post that informs WHY this is a fail. A zipper is thisclose to detaching the recovery system from the airframe, and endangering members of the public. Think of any major piece of your rocket that detaches at apogee, and burns in. Anything that gets dangerous to the Public gets banned. Try to buy a chemistry set, or a pair of lawn darts. Tripoli and NAR are providing insurance for us for following the rules; as the risk of damage increases, so does the level of responsibility. The certification process is the natural progression of this need for responsibility.
yes, this ignores the members of the staff, but they should have enough sense to look up, lol. That's why you get experienced people to work events. :)
The only thing that keeps this hobby alive is being risk adverse, and keeping the public at large from thinking we're a bunch of whackos reliving the v2 attacks on London.
I'll admit, I joined Tripoli because I was interested in making rocket motors. I used to to a lot of chemistry, and apcp motors seem to me to be a lot safer than the old ways.
In the course of learning urethane chemistry, and a whole bunch of organic chem, I realized just how bad it could go wrong working with these compounds, either as a mix, or a finished motor.
The thing I've learned over life is that the more energy involved, the worse it is when it goes bad. This includes all forms of energy, kinetic, chemical, pressure, temperature, all can bite you hard. And our entire world is one of unintended consequences.

I had a colleague learn that LN2 will collect O2 out of the air, and a magnet will pull droplets of it out of the ln2.
Anything oily burns in LNo2. See why they say "No food in labs":)?

Doing 140 down the interstate feels great, until your ponytail comes out of your leathers, lol. or you hit something; Newton is unforgiving.
Sure there was 14 seconds was just way to long of a delay.

Mike
 

Frederocket

Well-Known Member
TRF Supporter
Joined
Jul 31, 2011
Messages
585
Reaction score
194
Location
Maryland
Only somewhat related, but I went to a launch today and heard that a group of college students were there on Saturday to do their L1 certs. They were choosing the H550 as well. Is there some college challenge going on nation-wide that is driving the choice for the H550 as the motor of choice for beginner college L1 attempts. I've honestly never flown one. I got my L1 on an H97, L2 on J350 and largest motor I've flown to date was a K1100.

I think most of the L1 attempts I've seen over the years were on an H128. H550 is a much more aggressive and higher impulse motor. Just curious why people are choosing that for L1 attempts if they are in a college program.

Sandy.
What better way to test building skills than with a butt kicking motor, like the AT H550. Kind of reminds me of the old days when if your rocket could stand up to a Kosdon Fast load without a shred or ripping off a fin, you had a real winner.:):clapping:
 
Last edited:

wsume99

Well-Known Member
TRF Supporter
Joined
Feb 28, 2014
Messages
354
Reaction score
132
Location
Ohio
for sure more than helpful. I have a ton of notes and my professor is overwhelmed by the amount of information that HPR really is.
Yeah, this lesson was strange one at that. from trying to figure out how we got lucky, to possible reasons the rocket zippered, to understanding rules and regulations and then being guided in many different directions from local sources. Now that i understand how lvl 1 SHOULD work. I think my next launches will be better.

This is the root cause of the problem. Why in the hell is the professor assigning a capstone project that involves reaching L3 certification if he/she is personally overwhelmed by HPR?????? This is something that should be addressed by the dean of the engineering school IMO.
 

FredA

Well-Known Member
Joined
Jan 18, 2009
Messages
2,791
Reaction score
962
It’s simple. The Tripoli Forum is the only place where an official answer, relative to Tripoli rules or procedures, will be provided.
Really????
Your answers here seem to be as official as those over there....or do you answer differently here?
I don't see an "Official Q&A" section there.
Nor a "Rules FAQ" section being updated as these things come up.
Just a generic HelpDesk.

I see LESS activity there - do the TRA BOD read and interact there daily?
What I do see is [over] half of the flying world locked out over there and thus makes is way less interesting.
 

JoePfeiffer

OpenRocketeer
Joined
Jun 15, 2013
Messages
415
Reaction score
411
Location
Las Cruces, NM, USA
The H550ST is one of the few (maybe only) DMS motors that is also available as a RMS reload, it would be easy to miss that unless you either fly them or see them an awful lot at the preflight safety checks. I like punchy motors in small rockets for myself, love W9 and Vmax's.
I do too, but I wouldn't use one on a cert flight..
 

Pem Tech

Notorious Member
Joined
Jan 19, 2009
Messages
4,743
Reaction score
361
Location
Llama Central
Rather than trying to justify that “it’s not that bad”, own the failure - we all have them. Do a root cause analysis, and learn from it. Rather than convincing yourself “they were all the same”, think about the variables.
I second that emotion...
Accept that there was a problem and perform a failure analysis to identify the cause.
 
Joined
Dec 19, 2011
Messages
340
Reaction score
258
Location
Lebanon,IN
Certifications are about proving you have sufficient experience to fly safely. One part of that experience is flying enough to know when a simulation is not giving you good advice. Sometimes we learn it the hard way--like your situation--but often just asking the opinion of other seasoned flyers can tell you if you are "in the zone" for delays, altitude settings, etc. Let your simulations inform you, but always gut check them against real experiences. It's like the doctor who always takes what they see in the clinic over what they read in a medical book.
 

Steve Shannon

Well-Known Member
TRF Supporter
Joined
Jul 23, 2011
Messages
8,495
Reaction score
6,923
Location
Butte, Montana
Really????
Your answers here seem to be as official as those over there....or do you answer differently here?
I don't see an "Official Q&A" section there.
Nor a "Rules FAQ" section being updated as these things come up.
Just a generic HelpDesk.

I see LESS activity there - do the TRA BOD read and interact there daily?
What I do see is [over] half of the flying world locked out over there and thus makes is way less interesting.
I’ll always give answers to the best of my ability regardless of where I’m posting, but I’m no longer the president and my posts here don’t have any official status. And yes, I believe most (if not all) of the board feel obliged to read the Tripoli Forums as part of their duties.
 

Grog6

Well-Known Member
TRF Supporter
Joined
Jul 18, 2021
Messages
822
Reaction score
705
Location
Oak Ridge TN
Something I learned in 30 years of electronics is: Sims lie! Anytime you get near a boundry of an equation, or are trying really big or small numbers, they will gove you wonderfully wrong answers. At the extrees, where you put everything is more important than the value of the component. :) I was amazed to find out what it takes to make a 2ghz amplifier, and drive that signal 10" across a pcb, lol.
 

rharshberger

Well-Known Member
Joined
Oct 13, 2014
Messages
11,991
Reaction score
3,816
Location
Pasco, WA
I’ll always give answers to the best of my ability regardless of where I’m posting, but I’m no longer the president and my posts here don’t have any official status. And yes, I believe most (if not all) of the board feel obliged to read the Tripoli Forums as part of their duties.
Your answers Steve are almost always informative and precise, and very often quoting official sources (all good things). However as a member of the TRA BoD any responses you make here (or elsewhere) unless prefaced otherwise can be construed as an official position (or at least a level of approval) especially when its in reference to a thread like this one.
 

Steve Shannon

Well-Known Member
TRF Supporter
Joined
Jul 23, 2011
Messages
8,495
Reaction score
6,923
Location
Butte, Montana
Your answers Steve are almost always informative and precise, and very often quoting official sources (all good things). However as a member of the TRA BoD any responses you make here (or elsewhere) unless prefaced otherwise can be construed as an official position (or at least a level of approval) especially when its in reference to a thread like this one.
Then I will have to limit my participation here and that is probably for the best.
 

rharshberger

Well-Known Member
Joined
Oct 13, 2014
Messages
11,991
Reaction score
3,816
Location
Pasco, WA
Then I will have to limit my participation here and that is probably for the best.

That would be a loss Steve
It would be a loss, you have excellent and correct information, and you are a truly decent person and I can't recall ever "hearing/seeing" you be unnecessarily negative to anyone.
 

gldknght

Well-Known Member
Joined
Jan 26, 2011
Messages
1,000
Reaction score
267
Location
The Edge of Nowhere
My team did a lvl 1 flight today and one of the rockets didnt pass due to excessive damage, but the damage was minor and im not sure how it failed cert. The rocket can fly again easily. Here is an image of the damage. It flew with a H550 and a 14 second ejection delay. Now, im not slamming the committee who said it failed, i just want to understand so that next week our level 2 we dont run into issues.

View attachment 541930
Yeah, that's not "minor" damage. That's a major zipper and will require serious repairs to make the rocket safe to fly again. I would have given that a fail also.

I think you need a much shorter delay, but would need to see a video of your flight to say for certain.
 

gldknght

Well-Known Member
Joined
Jan 26, 2011
Messages
1,000
Reaction score
267
Location
The Edge of Nowhere
Please help us understand why it is catastrophic? is it because if we stuck a new h550 in it, it wouldnt fly?
This, exactly. That rocket with that huge zipper (yes, it IS a huge zipper) will not safely fly again without major repair. No LCO / RSO would allow it. It would be dangerous, because as soon as the rocket left the launch pad, it would most likely come apart. Burning rocket motor parts on the ground, fire hazard, Uncontrolled rocket parts flying around, I shouldn't even need to say how bad that is!

Whether the rocket is repairable is beside the point. It can not fly as is. That's the definition of catastrophic failure.
 

smstachwick

LPR/MPR sport flier with an eye to HPR and scale
TRF Supporter
Joined
Jul 29, 2021
Messages
2,654
Reaction score
2,571
Location
Poway, CA
This, exactly. That rocket with that huge zipper (yes, it IS a huge zipper) will not safely fly again without major repair. No LCO / RSO would allow it. It would be dangerous, because as soon as the rocket left the launch pad, it would most likely come apart. Burning rocket motor parts on the ground, fire hazard, Uncontrolled rocket parts flying around, I shouldn't even need to say how bad that is!

Whether the rocket is repairable is beside the point. It can not fly as is. That's the definition of catastrophic failure.
Correct.

However, there have been about 6 pages of discussion on this, not all of it respectful. I think the topic is done unless we get new developments.
 
Top