lakeroadster
When in doubt... build hell-for-stout!
Updated list 2019-07-08: see post #1
I disagree with making MESS available. There are way too many problems with this.
I disagree with making MESS available. There are way too many problems with this.
1. We don't know ABSOLUTELY what happened with the motor....if black powder, was it thermal cycled? If composite and single use, was it dropped?
2. We don't know ABSOLUTELY how the motor was built (reloadables) I was at a launch, the motor cato's, the LCO tells the flyer to get another motor and reload from me (I am a vendor). I got to the rocket and the problem was obvious - it was a AT motor, where they put the spacer on the nozzle side of the forward closure. This was absolutely operator error. Now let's talk about ungreased O rings, missing phenolic discs, cross-threaded CTI 38's.
3. We don't know ABSOLUTELY why the motor failed. I've been doing it for a long while, but I bet I haven't seen everything.....and sometimes there's not enough to do a post mortum.
4. We don't ABSOLUTELY know there's a issue with a lot, date of manufacture or type. It could have just been a one-off problem, such as a bubble in the propellant, a bad liner, crappy O ring or just bad luck. Don't forget NASA lost a few space shuttles. Anecdotal reports are generally not statistically significant. We also haven't talked about what is significant...5% of a lot? If that were the case a lot of 1000 would need 51 failures, only attributable to the motor, to have some significance.
5. If we get to blaming every one-off or any of the above failures on the motor, it costs someone money. Either dealers eat the motors or the manufacture would have to. Either way is unfair....
6. No other American system is set up to report singular failures (or for that matter, few are set up for multiple failures). Go ahead and try to find manufacture data on how many microwaves of a certain model failed, or how many washing machines failed. I feel fairly confident in stating that everyone's vehicle will fail eventually, in some way. The battery in my F350 died after 5 years outside....expected, but a failure none the same. Anyone gonna stop buying some sort of vehicle? Anyone yelling to find out how many F350 batteries died in 5 years?
ps JMHO but if you work that hard to make a beautiful model, then you accept the risk when you go to fly it. my Decim8te got wrecked hitting a tree limb, under full chute. Stuff happens. I admire the work of the space modelers in our group and a good friend is one. I don't have 10% his skill, and admire his work. He's done a lot of re-do's because the finish got scratched on a nominal flight....never complains......
You could use this same "don't allow the free sharing of data" for pretty much everything in life.
I'd rather have the data and make up my own mind.
E9 and E12 motors are the perfect example of why users should share data. We ABSOLUTELY know they are more prone to CATO than the other variants of BP motors.
hmm... let's crowd source another decision...
cars kill people, directly due to failures https://www.ranker.com/list/catastrophic-car-failures/amandatullos
bicycles safe? https://www.rospa.com/rospaweb/docs...fety/cyclists/cycling-accidents-factsheet.pdf
guess not
guess we're to horses....
https://mentalfloss.com/article/91277/australia-horses-kill-more-people-venomous-creatures-do
walking?
https://www.nsc.org/home-safety/safety-topics/distracted-walking
guess we should all stay home. Isn't that one way to look at the data? Isn't everything else NOT SAFE because you risk DEATH?
ps I absolutely fly my loc viper 4 on D12-7's, every time.....never been a fan of the E9, mostly because it burns so long and doesn't have a whole lot of thrust.
It would also be interesting to have a lawyer speak on liable issues from accusing a motor to be bad...Not that they would, but could. I'm too old to mess with that gimble lock. I want to retire SOON.
pss. now show me one other consumer product where crowd sourced data is absolutely shared at a per incident / per person level.......
I agree with cbrarick, unless you know how many motors were produced from each lot the reported failures are only anecdotal. Even then, it may not be statistically significant... if you have one cato on a 98mm N motor and the manufacturer only produced 100 of them, is that any different than 1,000 catos on a motor where 100,000 were produced? Generally, only the manufacturers have that data, and that fact that vendors have instituted recalls and remediations for some of their products (i.e. CTI 38mm forward closure issue, AT DMS L1000 case issue, etc.) based on user-submitted incidents shows that the current system is working.
I agree with cbrarick, unless you know how many motors were produced from each lot the reported failures are only anecdotal. Even then, it may not be statistically significant... if you have one cato on a 98mm N motor and the manufacturer only produced 100 of them, is that any different than 1,000 catos on a motor where 100,000 were produced? Generally, only the manufacturers have that data, and that fact that vendors have instituted recalls and remediations for some of their products (i.e. CTI 38mm forward closure issue, AT DMS L1000 case issue, etc.) based on user-submitted incidents shows that the current system is working.
I don't think anyone is asking for statistical analysis of the data or absolutes, only high level trending data. If a motor has been on the market for 15 years with no reported failures and suddenly there are 10 reported failures in the span of a few months, all in the same manner by different people and the commonality is that they all came from a certain batch, then why would you not support adding that batch to a "suspected bad motor" list?
geez didn't mean to be condescending..I actually said I wasn't qualified to do the analysis. You can be a math savant and not understand the question, therefore not be qualified to perform the analysis. I"m really glad that we have the two organizations doing it for us. They are immersed in a way that they probably ask questions we haven't even considered. The problem is that counts of motor blowing up don't do much good.
Even Charle's data is limited in it's use. His review found 6.78% of E9s and 6.98% of E12s Catoe'd...out of a convenience sample of I don't know how many.....
Plus, there's a participation bias. I rarely post any flights and never post commercial CATOs. You? Isn't there a selection bias as to who posts: Those who enjoy that and those that had a bad experience...Others? I don't know. Plus there's another selection bias - you gotta know about the site to do your rocket review, and have a machine that allows you to do so. Apparently C6's never CATO on rocketreviews, but I've seen it happen. then you have to throw in the independent variable of lot/manufacture date. Perhaps (I really don't know) the E9's only blew in one batch, making that one higher and every other lot zero, absolutely safe..... I think, after a long time going to lots of launches, that I've seen close to one of everything CATO. It's the risks we take when we fly.
I, for one, hope that before either cato site releases data to the general public, they consult their lawyers. i'd be curious what they say. They may not like the idea.
Anyhow, peace out everyone. For those that don't like my opinion, please forgive me and forget it...cause I'm out of here....
geez didn't mean to be condescending..I actually said I wasn't qualified to do the analysis. You can be a math savant and not understand the question, therefore not be qualified to perform the analysis. I"m really glad that we have the two organizations doing it for us. They are immersed in a way that they probably ask questions we haven't even considered. The problem is that counts of motor blowing up don't do much good.
Even Charle's data is limited in it's use. His review found 6.78% of E9s and 6.98% of E12s Catoe'd...out of a convenience sample of I don't know how many.....
Plus, there's a participation bias. I rarely post any flights and never post commercial CATOs. You? Isn't there a selection bias as to who posts: Those who enjoy that and those that had a bad experience...Others? I don't know. Plus there's another selection bias - you gotta know about the site to do your rocket review, and have a machine that allows you to do so. Apparently C6's never CATO on rocketreviews, but I've seen it happen. then you have to throw in the independent variable of lot/manufacture date. Perhaps (I really don't know) the E9's only blew in one batch, making that one higher and every other lot zero, absolutely safe..... I think, after a long time going to lots of launches, that I've seen close to one of everything CATO. It's the risks we take when we fly.
I, for one, hope that before either cato site releases data to the general public, they consult their lawyers. i'd be curious what they say. They may not like the idea.
Anyhow, peace out everyone. For those that don't like my opinion, please forgive me and forget it...cause I'm out of here....
MESS reports are not useless. There is far more data in the MESS database than anywhere else. We are in the process of making it more widely available.Why? MESS reports are essentially useless.
I posted this in another thread, but here's a demo site where you can see the current status:
https://motorcato.herokuapp.com/
Thanks for the suggestions; I'll think more about them. Sorting by date should be easy. The database doesn't have info other than what is entered, but could be enriched through ThrustCurve.org.I'd like to offer some feedback and make some requests.
Thanks John. I can see my own reports!
I'd like to offer some feedback and make some requests.
- The searches come up with date order scrambled. It would be nice to sort newest-oldest by default.
- I'd like a motor diameter sort column or filter option. That might not be in the database (at least without a join) so it might not be an easy request, I'm guessing. I asked because I was looking at the Pro38 1G failures, and I recognized my G78BS - but the related motors (like G69SK) didn't pop to me. I had to look at Pro38.com to check the codes and see the commonality.
- If there is only one failure of a motor designation, clicking the link takes you to that mess - full text description, categorical entries, etc. Otherwise, I don't see a way to get to a specific report. The motor designation links pull up all the failures for that motor. I'm thinking one or the other is a mistake. Try 'P38'. I also tried a date search to get to a single motor listing, but it still pulled up list of all reports for that motor.
- Speaking of which, is there a handy way to validate the motor designation? Maybe against the Thrustcurve database? The P38 above is actually a J530. Some quick browsing and searching highlights the errors in data entry. SU v reload seems to be very common.
- Search by location?
- Search/order by propellant?
Thanks for the suggestions; I'll think more about them. Sorting by date should be easy. The database doesn't have info other than what is entered, but could be enriched through ThrustCurve.org.
The first column in search results (the clipboard) will take you to that single report. Clicking on a manufacturer will take you to all reports for that manufacturer and clicking on a common name will take you to all reports for that motor. (As you noticed, if there is only one report, it takes you to the detailed data for that report.) This seems logical to me, but you're the second person to mention that the behavior isn't intuitive, so something needs to be done here.
The common CATOs I've seen in the BP 24mm motors are spitting the nozzle aft, and/or spitting the whole fuel grain forward. So nozzle problems and grain to casing adhesion problems.
Composite motors have their own issues. Nothing is perfect.
Enter your email address to join: