Tripoli booting FAR?

[TonyL]

This seems like an unfortunate precedent. I believe that the majority of organizations to whom FAR provides services are universities and not necessarily TRA members.

This edict suggests that following the TRA safety code to the letter is no longer sufficient, and that events and activities are also subject to approval by the BOD.

The obvious question is whether the BOD is planning on editing the TUSC to reflect this additional requirement, or just add language that FAR is excluded as a place that can host "Tripoli Launches" per the safety code definition? Neither seems appropriate.

That FAR does not necessarily follow the TRA safety code for non-TRA activities seems besides the point.

One would think that the more constructive response would be to educate the membership that activities at FAR that are not in conformance with the TRA safety code are not considered "Tripoli launches", and thus are not covered by TRA insurance, same as any other non-TRA safety code compliant activity anywhere else.

 

[AlexBruccoleri]

Not true. The safe distances for model rockets has its foundation in an analysis done at MIT. There are plenty of other models out there for blast field prediction based on energy, action time, material size and density. There have also been tests to verify the models (NM Tech in Socorro has done this work). I'm not going to point to them on the open web. Make whatever conclusion you want, but educate yourself first.

I straight up asked the pyrotechnics committee for reference material and they referenced the Jay Apt report, which is great work but not what I was looking for. I am looking for some models that derive the safe distance table. If you claim such analysis exist for NFPA 1127 (not 1122) please share it or send a link. I am eager to “educate myself”, as you suggest.

 

[ksaves2]

NAR insurance covers you wherever you launch as long as the safety code is followed. This isn’t the case with TRA. But for the purpose of a certification flight, it can take place anywhere the safety code is followed and the waiver is valid. That doesn’t mean the insurance is active.

NAR only covers for certified motor loads. I highly doubt that's what is being used here. TRA covers research loads at an appropriate site. If TRA hierarchy wants to vacate them (FAR), fine by me as I trust the hierarchy. If they're (FAR) is doing some really big dangerous stuff that TRA feels the site can't handle, then ditch them as I don't want to be paying their insurance fees!!!

Yeah, I fly modroc stuff at a site around the corner from me but I DO NOT violate motor impulse rules. Am NAR/TRA dual member as I got involved in mixing propellant years ago. Only take certified loads to an NAR sponsered launch and leave my mixed stuff at home.

There was a mentor who come down to our TRA club to show us how to mix and he clued us in to Dr. McCreary's classic book on the subject. The local TRA prefect bought a commercial mixer and we could mix 20kgs. of propellant at a time. Only deal was to agree on what mix to make which wasn't hard to do. Tiger tail, Wimpy red and a host of others in my notebook downstairs that I know where it's at!! Only thing one had to do was bring chems, casting tubes or labor. Those days were so much fun doing rocket community mixing in the Spring and Summer. I did some small time mixing in my garage. If a flyer was in financial straits they'd still get grains to take home for their motors from a community mix. I thought that was so cool.

One bit of advice, "Never buy a Kitchen Aid mixer from a rocket guy for food!" Can never get the chemicals out of the paddle or bowl. A mentor told me that.

Oh if a TRA flier was in a bit of financial distress, no problem. The prefect had bought over 2000 lbs of various AP grain sizes and if the flier helped with the mixing and packing, they'd get some grains to take home for their hardware. The prefect was "hardcore" if you ask me.

Shoot if there was a batch mixing scheduled and we decided what kind of mix in advance, I'd calculate how much AP of various grain sizes it would take for the motors I wanted along with the mag and other additives. R45, curative etc. and bring it in from my stash to dump into the pot. We didn't do motors that needed to be baked in an oven like PBAN. I saw some PBAN research motors go up at a research launch one time and man did they have a "kick". The club didn't have an oven to "bake" rocket motors so we stayed away from PBAN and stuck with HTPB that could cure at room temp. Once a rocket motor oven always a rocket motor oven. Didn't want to invest in that. HTPB was fun enough.

At most mixing sessions I went to the prefect would say, "You're the doctor you do the mix!" Yeah I have an M.D. though retired now and had a background in biochemistry in ancient times before all this DNA sequencing stuff came out. Mixing chems was still in my mind so it was easy to measure and mix in an industrial mixer. The club members would get drunk on beer but I only drank water or soda pop while mixing. Drunk folks can still hand pack pretty good. The prefect invested in a very accurate scale that I figured out how to use in an instant. Once everything was packed and done, I'd have a beer or two.

Man those were fun days. Prefect eventually died, the TRA prefecture folded and the launchsite went fallow. Still, nice memories for me.

Kurt

 

[bad_idea]

If they're (FAR) is doing some really big dangerous stuff that TRA feels the site can't handle, then ditch them as I don't want to be paying their insurance fees!!!

Don't worry, you weren't paying their insurance fees. The overwhelming majority of FAR activities - including this recent P test - do not conform to the Tripoli safety code but are rather performed under FAR's safety rules. As they are not TRA safety code compliant, they were never covered by Tripoli insurance.

The only FAR activities which would have been insured by TRA insurance were occasional launches where TRA distances and other rules were observed as a service to Tripoli members who specially requested a TRA-compliant launch. I'm told that was exceedingly rare.

Yeah, I fly modroc stuff at a site around the corner from me but I DO NOT violate motor impulse rules. Am NAR/TRA dual member as I got involved in mixing propellant years ago. Only take certified loads to an NAR sponsered launch and leave my mixed stuff at home.

In case you're flying research on your local field and you don't know (a lot of people don't), TRA insurance requires prior approval of the launch site. I believe the review and approval process is started upon submission of the landowner form, but not having had reason to do this myself so far, I've not reached out to the insurance contacts at TRA to ask the specifics.

 

[TonyL]

Well I guess I have learned something about TRA insurance, and on topics which never really come up when setting up a home field and doing the usual garden variety paperwork.

That said, the safety code only mentions 'landowner permission/constraints followed' without any definition that was easy to tie directly to this statement. If there is some requirement between issuing a 'certificate of liability insurance' and 'landowner permission', it is not clearly indicated from my reading. Along those lines, the insurance page implies that a member's activities are also covered at non-TRA events that follow the safety code, but it is not clear that this is or is not the case from reading the different levels of requirements for insurance coverage.

Ultimately I don't particularly care which way it is defined, as long as it is clearly communicated [which I would argue it could definitely improve]. I use FAR for my purposes and never had any expectation of TRA insurance because the letter of the code was not practical to follow, however safe practices were and will be followed there when I do my testing.

 

[bad_idea]

Along those lines, the insurance page implies that a member's activities are also covered at non-TRA events that follow the safety code, but it is not clear that this is or is not the case from reading the different levels of requirements for insurance coverage.

The insurance page specifically mentions the insurance is valid at "approved launch locations" and goes on in the FAQ to discuss the need for TRA to do risk assessment of a launch site for it to be covered. I agree it could be a lot more clear what steps should be followed. I've been thinking it would be nice to have TRA insurance as well as NAR insurance when flying at my local park, so maybe I'll go down that road myself sometime soon.

 

[rcktnut]

There WAS a P cato. There's no "what if", the question is "what has occurred?" We have the opportunity to learn from it. Checking the debris field is one of those things that needs to be done to validate the safe distances we use.

Those safe distances were recently brought back for experimental motors to the same as commercial motors.

Although this was NOT a Tripoli launch, Tripoli has the opportunity to validate their own safety distances. Failure to do so would be a missed opportunity. P catos don't occur that often so the data set we're using cannot be that large for our safety assurance.

No 2 P catos are going to be the same or any motor designation for that matter. I always thought that the minimum safe distances were established for protection from a rocket strike rather than a motor cato. I don't know about EX but I always thought that in the event of motor over pressurization they were designed to blow the aft closure off. I know I seen split casings already, but they were just that split and not totally fragmented. There is nothing to stop anybody from moving further away if not comfy with the minimum requirement.

 

[OzHybrid]

No 2 P catos are going to be the same or any motor designation for that matter. I always thought that the minimum safe distances were established for protection from a rocket strike rather than a motor cato. I don't know about EX but I always thought that in the event of motor over pressurization they were designed to blow the aft closure off. I know I seen split casings already, but they were just that split and not totally fragmented. There is nothing to stop anybody from moving further away if not comfy with the minimum requirement.

This is about examining the evidence from an actual event and using that evidence to validate Tripoli or any other organisations launch safety distances. Not about anyones preferences. Evidence based safety distances.
If the debris is within those distances you can say " we checked, and the safe distances are set correctly." If not adjust them.
But if we don't check them, "Why not?" would be a legitimate question from an insurance company. Us monitoring our own safety is a better option. And it's not difficult. And then we can say we did it. If asked.....
Insurance companies have a habit of denying you insurance for something that you reasonably should have known. So we should, very reasonably check, that we don't know it.....or should have known.

 

[terryg]

Ehh, there's P (and larger) CATOs at BALLS every year that they could be looking at if they needed to. I don't know the exact success rate, but I know it isn't very high. At least people are further away, and I say that as someone who has attended plenty of both FAR and TRA events and plans to go to more of both.

Any links to videos of these CATOs? This the most spectacular one that I have seen!

 

[eggplant]

Any links to videos of these CATOs? This the most spectacular one that I have seen!

The CU P was especially "showy", probably because the under-cured propellant fractured into a lot of tiny pieces, which then went in every direction, making a firework effect.

I'm not too much of a CATO connoisseur, as I don't think it is a part of our hobby that we should celebrate or share too much outside of safety discussions. But seeing as this is sort of a safety discussion, here are a couple that I think are notable:

First, one that was at Airfest rather than BALLS, but is definitely one of the most energetic I've seen video of:

Must have happened at extremely high pressure. Note that it did send out a ton of shrapnel (some of which landed _quite_ far from the pad), and a voice on an intercom, probably the RSO, laughs and says "do it again". Even if they stand a bit too close at FAR, that's not an attitude I've personally heard there.

Here's one from a while ago:

Notice the van parked near the pad. It isn't being used this way in this video, but I've seen plenty of older videos from BALLS where people use a vehicle as cover to stand really close to a rocket. I haven't seen this as much in videos from recent years, but it seems they used to operate on closer to FAR rules.

Finally, here's an R letting go:

This one seems to have been observed from a reasonable distance!

 

[ksaves2]

In case you're flying research on your local field and you don't know (a lot of people don't), TRA insurance requires prior approval of the launch site. I believe the review and approval process is started upon submission of the landowner form, but not having had reason to do this myself so far, I've not reached out to the insurance contacts at TRA to ask the specifics.

I just use bp and small commercial APCP commercial motors for local flights and follow modroc rules. Don't do research at the local field though I've done ground tests with a hole in the ground there. Sure I'm on my own with that but nothing is flying so I can live with the risk as I have a remote ignition system and can stand a very......long....ways away. With small motor testing, I've never had an "over pressurization". It's actually a city golf driving range and with good weather, the duffers go out to the links in the early mornings and don't do the driving range. I was usually the only one out there most of the time. The city put a small parking lot in the southwest corner for R/C people and hobbyists. That's where I go. I used to fly R/C sailplanes, planes and helicopters there but sold off all my R/C stuff as I was bored with it and didn't have the time to fly when working. The city meant the area to be used for that. Now retired, I wished I would have kept all the R/C stuff. Big mistake on my part.
I remember one time in the early morning I flew a very small DD rocket that went up high. I had been flying some small BP rockets and there were a few duffers on the driving range. The field is extremely large so I didn't and they didn't have an issue with it. They knew I was flying and the rockets landed off to the side from them. The DD rocket went up, I glanced and the three duffers looked up and the rocket had a good smoke trail. I and they saw the apogee event and of course the rocket was descending at a high rate of speed under drogue as planned. The main blew, deployed nominally and landed close to them softly. I went over to collect the rocket and the golfers were "blown away" as to how I did that. I got the rocket and showed them it, the electronics and how the magic is done. They were enthused but I told them I was done flying for the day as I launched all my prepped rockets by then and they don't have to
worry about it if they want to continue practicing driving balls. The amazement on a person's face for the first time that we rocket people take for granted with the expected flight events is a true pleasure to see. I've been at this for over 15 years so I've kept updated on the rules by NAR and TRA. I only go to a certified launch site to do HPR associated with a club.

 

[High Desert Rocketry]

No 2 P catos are going to be the same or any motor designation for that matter. I always thought that the minimum safe distances were established for protection from a rocket strike rather than a motor cato. I don't know about EX but I always thought that in the event of motor over pressurization they were designed to blow the aft closure off. I know I seen split casings already, but they were just that split and not totally fragmented. There is nothing to stop anybody from moving further away if not comfy with the minimum requirement.

Safe distance does not protect against a rocket strike. The farther the pad, the faster the rocket will be traveling into the flight line if it goes 'cruise missile' or 'land shark'. Also, unless built correctly with a secure launch pad and angled away from the flight line, a rocket could come down ballistically on the flight line, I'm sure most of us going to launch events have witnessed this. And this is the reason when I do RSO/LCO at FAR I ask people to stop what they're doing when they hear a countdown and look at the rocket launch to make sure it goes vertical AND deploys a chute.

Prepping rockets under an easy up or in an RV doesn't help when they call out 'Heads Up'. How easy is it to see a 38 or even a 54mm minimum diameter rocket coming down ballistically from 10,000' that is headed for you? At FAR you can step under our reinforced concrete overhead protection bunker. I'm not saying our bunkers are always superior to 'safe distance' as it depends on what is happening to the rocket. I can say that for commonly doing both large experimental solid and liquid bi-prop rockets, launches to over 50,000', and just about every weekend, with thousands of people a year, to my knowledge, our only injury has been taken care of with a band-aid.

As for fragments, I've had aluminum motor cases fragment in as many as 15 sharp-edged pieces and have known other people who have fragmented them into even more pieces and fragments falling from a rocket high up in flight don't follow 'safe distance'.. Launching HPR is a dangerous activity that demands paying attention to what you are doing and what is going on for your safety and the safety of others. I launched my first EX (research rocket) 65 years ago and many since and was only injured when driving from the airport to the motel at a rocket competition back east with students when a driver on the interstate fell asleep and smashed into us causing me and another student to go to 'an unplanned visit to the ER'.

 

[High Desert Rocketry]

A group was about 1/2 miles or so away and took this video. You can see how far some of the grain were projected. One grain went through the skylight of the prep building and started a fire inside.

This also shows why 2000 ft is a good safe distance.

That video looks like it was taken from our neighbor's test/launch facility. We at one time were going to do a L-3 cert with the flyer using a N-impulse motor. That requires 1,000' TRA 'safe distance'. Our option to do this was to either have everyone from the FAR facility go 1,000' away or launch from 1,000' away. We secured permission from the neighboring facility to launch the rocket from there. Based on the measurements we did, this video in question taken from the Ryder rental truck was less than 1,000' away.

Safe distance is great and I always used it when doing association certs or record flights, so are the bunkers. A combination of both is ideal.

 

[ksaves2]

Ahhh when our local group was doing research stuff. Did a test with a 75mm cased M motor we mixed.

HTBP and let it cure for a couple of days. The L3 Prefect was in a semi-rural area and it was in the "early" days of Ex (oh gosh) research motors.

The butt end third of the homemade snap ringed cased motor was above the ground hole. The button was pushed and an over pressurization occurred that blew the case wide open. The back end flew between me and the Prefect! We were standing wide apart over a hundred and something feet away but heard the whistling of the shard between us.

It was the lower third of the motor casing and the Al was splayed out and could have sliced anyone in it's path to bits. Had to walk a long ways to pick up the
piece and it was before I had a cellphone that could take pictures.

Thank heavens his neighbors were supportive of our rocketry endeavors. Man, I wished I could have inherited that fragment when the Prefect died
of natural causes several years later. It was so dastardly looking. I'm not proud of it but we became more cautious because of it.

We buried our motor tests so much deeper into the ground thereafter. Didn't have any flying shards to deal with. Just maybe a small crater.

Kurt

 

[ksaves2]

Ahhhh, The deal with big mixed motors is this and only this.......... Trying to test an extremely large motor is pretty difficult for many.
After buying all the "stuff" to make the motor they likely just go with whatever a motor simulator tells them to do. Unfortunately, that's not good enough.

Make the motor without doing a ground test and one is flirt'in with disaster.
The thing is investing the $$$$$ to make a large motor makes it hard to do appropriate testing because it costs so much. Hence the "overpressurization" stuff that is seen in a myriad of videos out there.

With large amateur mixed motors, I'd say above N or O it might take a tractor with a backhoe to dig a test hole if one wanted to do a test.

If one's motor case blows even in a test firing, it's a big pile of money down the hole. Hence one is going to continue to see larger mixed motor rockets over pressurize and blow at launches because it's too much money to test appropriately. Kurt (a curmudgeon)

 

[rcktnut]

Safe distance does not protect against a rocket strike. The farther the pad, the faster the rocket will be traveling into the flight line if it goes 'cruise missile' or 'land shark'. Also, unless built correctly with a secure launch pad and angled away from the flight line, a rocket could come down ballistically on the flight line, I'm sure most of us going to launch events have witnessed this. And this is the reason when I do RSO/LCO at FAR I ask people to stop what they're doing when they hear a countdown and look at the rocket launch to make sure it goes vertical AND deploys a chute.

Prepping rockets under an easy up or in an RV doesn't help when they call out 'Heads Up'. How easy is it to see a 38 or even a 54mm minimum diameter rocket coming down ballistically from 10,000' that is headed for you? At FAR you can step under our reinforced concrete overhead protection bunker. I'm not saying our bunkers are always superior to 'safe distance' as it depends on what is happening to the rocket. I can say that for commonly doing both large experimental solid and liquid bi-prop rockets, launches to over 50,000', and just about every weekend, with thousands of people a year, to my knowledge, our only injury has been taken care of with a band-aid.

As for fragments, I've had aluminum motor cases fragment in as many as 15 sharp-edged pieces and have known other people who have fragmented them into even more pieces and fragments falling from a rocket high up in flight don't follow 'safe distance'.. Launching HPR is a dangerous activity that demands paying attention to what you are doing and what is going on for your safety and the safety of others. I launched my first EX (research rocket) 65 years ago and many since and was only injured when driving from the airport to the motel at a rocket competition back east with students when a driver on the interstate fell asleep and smashed into us causing me and another student to go to 'an unplanned visit to the ER'.

The further away you are from a rocket when launched the more time you have to react in case of a land shark, unstable rocket etc. In my post I thought that was the basic reason for the establishment of a minimum safe distance. I don't think the sole reason is because of a possible motor cato. I was defending the 2000 ft distance from the P motor. I was reacting to post # 76 calling for an investigation of lets call it the blast radius. I personally feel totally safe being that distance from a P as compared to 15ft. from a D or 30 ft. from a G impulse motor. I most definitely agree there is no such thing as a safe distance as far as ballistic recoveries, high altitude catos, or shreds go.

 

[High Desert Rocketry]

Ahhhh, The deal with big mixed motors is this and only this.......... Trying to test an extremely large motor is pretty difficult for many.
After buying all the "stuff" to make the motor they likely just go with whatever a motor simulator tells them to do. Unfortunately, that's not good enough.

Make the motor without doing a ground test and one is flirt'in with disaster.
The thing is investing the $$$$$ to make a large motor makes it hard to do appropriate testing because it costs so much. Hence the "overpressurization" stuff that is seen in a myriad of videos out there.

With large amateur mixed motors, I'd say above N or O it might take a tractor with a backhoe to dig a test hole if one wanted to do a test.

If one's motor case blows even in a test firing, it's a big pile of money down the hole. Hence one is going to continue to see larger mixed motor rockets over pressurize and blow at launches because it's too much money to test appropriately. Kurt (a curmudgeon)

I wasn't at Sunday's 'P' motor incident, I left Saturday after the launch waiver ended but from what people told me they had static tested the motor a couple of times and this was to be the flight, so I was told. But successful static testing doesn't guarantee all the following motors will behave nominally...just look at how many commercial motors CATO for various reasons. But you are correct, big motors 'should' be static tested before flying them. Largest EX motor I've flown was a 6" full O but that was having done the testing of numerous other motors up to Q-impulse. But all the full O motors performed as expected...knock on wood.

We static tested 3 large 12" motors, each larger than the previous (more grains), and all were done with holes dug into the ground to minimize the radial spread of fragments if a CATO occurred. There are both advantages and disadvantages to using that method.