Side question on the freefalling rocket discussion

[clscharrer]

Although I built my first rocket in the 70's, I didn't start flying them until a few years ago (an unrelated discussion), so I am a rookie in this arena. I agree with the general population of the group about following the safety rules, and not try to develop a rocket that is inherently unsafe by design. That said, what if the rocket is an off the shelf production version, with seemingly unsafe parts? I have purchased a couple of small 1.5" fiberglass MPR's from what I would consider one of the major manufacturers, and the nose cones have very pointy aluminum tips. The look is real cool, but I wince when I look at them and think about what could happen if the recovery system malfunctions. Most of my rockets are fiberglass medium power, (my training back in the day was custom cars so my passion for this sport is a lot about finished Hot Rods). My fleet is no frills, fairly robust but easy to repair if needed, and the fins and nose cone tips do get banged up on good flights. But I look at these two new ones and can only imagine how bad their flights could end. Are these metal tipped nose cones considered a safety risk? I have thought about blunting them but I am pretty sure that is inconsequential to what might happen if they come in ballistic. Is there an unspoken rule I missed?

 

[Steve Shannon]

Those small nosecone would be prohibited by the model rocket safety code. The high power safety codes don’t prohibit metal tips and simply restrict the use of metal to “as needed.”

First, I’m not a fan of metal tips on high power rockets, but that is just my opinion. In my opinion they’re just not needed, although a lot of people seem to believe they are for supersonic flights to prevent heat damage. The thing is, having a pointy tip actually increases the heat concentration. A rounded tip of would not heat up as much but would create more drag. I believe there’s a sweet spot where a small rounded tip of wood or a thermosetting compound would work well without looking as dangerous. And that’s where the danger lies in my opinion, the immediate perception people have when they see a very sharp metal tip on a nosecone doesn’t exactly scream “It’s all about safety!”
But, realistically, if a person were ever struck by a high power rocket under flight, the presence or absence of a metal tip would almost certainly provide no added risk or protection.

 

[CPUTommy]

If building a rocket properly, with the right adhesive, with the correct motor, there is usually no issues.
Now Darwin steps in.
He has helped me achieve
-motor failure on ignition..
-motor failure on lift
-motor retention on boost
-motor delay failure
-shock cord separation
-chute not opening
My best was when the shock cord broke and the nose cone was perfectly weighted which made the chute climb and climb until it hit the jet stream and left this country.. its probably in England somewhere at this point. I RECOVERED THE ROCKET minus the nose cone and chute.

I had to have these failures in order to improve my building. I've made changes to fly bigger more powerful rockets is a natural progression. Launch enough rockets and you WILL have failures, the ones you can control are what you improve. The failures that happen. Well.. welcome to rocketry.

 

[clscharrer]

Those small nosecone would be prohibited by the model rocket safety code. The high power safety codes don’t prohibit metal tips and simply restrict the use of metal to “as needed.”

Just to be clear, if I want to launch these with G or smaller, I would probably violate the code. If I wanted to go with a H or higher (they are only 29mm mounts, so not a lot of options there), that would be OK? I doubt I could do that where we launch since our waiver is only 3500', and small G's are sim'ing close to that for these two runts. I also don't have L1 yet, but have another larger rocket to go for that this summer, a little better suited for the field we use. Sounds like I just need to hunt down a 1.5" VK plastic nose cone I can stick on these for launches, then put the shiny spearheads back on for display.

 

[High Desert Rocketry]

The last person I heard of that was killed by a model rocket was with a cardboard rocket and plastic nose cone.

All can be dangerous. That is why construction/preparation and attention during launches are always important.

 

[Steve Shannon]

Just to be clear, if I want to launch these with G or smaller, I would probably violate the code. If I wanted to go with a H or higher (they are only 29mm mounts, so not a lot of options there), that would be OK? I doubt I could do that where we launch since our waiver is only 3500', and small G's are sim'ing close to that for these two runts. I also don't have L1 yet, but have another larger rocket to go for that this summer, a little better suited for the field we use. Sounds like I just need to hunt down a 1.5" VK plastic nose cone I can stick on these for launches, then put the shiny spearheads back on for display.

There are lots of 29 mm motors in the H and I impulse ranges. It’s also possible for G powered rockets to be high power rockets, based on the actual definition of high power motors that is established in NFPA 1125 and 1127. Good luck with your certification this summer!

 

[icyclops]

Just to be clear, if I want to launch these with G or smaller, I would probably violate the code. If I wanted to go with a H or higher (they are only 29mm mounts, so not a lot of options there), that would be OK? I doubt I could do that where we launch since our waiver is only 3500', and small G's are sim'ing close to that for these two runts. I also don't have L1 yet, but have another larger rocket to go for that this summer, a little better suited for the field we use. Sounds like I just need to hunt down a 1.5" VK plastic nose cone I can stick on these for launches, then put the shiny spearheads back on for display.

Sounds like a plan...

 

[teepot]

If you swap nose cones your going to have to rebalance the rocket for CG. And maybe for CP too if the profiles of the two cones are different.

 

[tab28682]

Now Darwin steps in.
.....
My best was when the shock cord broke and the nose cone was perfectly weighted which made the chute climb and climb until it hit the jet stream and left this country.. its probably in England somewhere at this point. I RECOVERED THE ROCKET minus the nose cone........

Just to prevent others from misunderstsnding, a "perfectly weighted" nose cone on a parachute does not cause the laws of gravity to be repealed.

A nose cone on a parachute will climb only if the air mass it is in is climbing, as a result of a thermal or something similar.

On the original topic: Given that cardboard airframes and plastic nose cones have been involved in a fatal accident and have penetrated automotive sheet metal and glass, I do not see any additional risk to people or property with a small metal tip on a nose.

 

[CPUTommy]

After a serious crash, im really rethinking the metal nose cones.

Seen to many punch holes in the ice....

Just cant fathom it hitting ANYTHING.

 

[BABAR]

On the original topic: Given that cardboard airframes and plastic nose cones have been involved in a fatal accident and have penetrated automotive sheet metal and glass, I do not see any additional risk to people or property with a small metal tip on a nose.

You are certainly entitled to your opinion, and in this case you make a decent argument that you are right.

doesn’t change the rules. For high power, metal used may be allowed “as necessary” for high power launches. However, high power launches require a waiver and are commonly performed at clubs Where an RSO reviews the rocket for safety and makes a determination of whether the metal is “as necessary” or not.

low power. NAR rule NUMBER 1.

“Materials. I will use only lightweight, non-metal parts for the nose, body, and fins of my rocket.”

https://www.nar.org/safety-information/model-rocket-safety-code/
Your opinion, no matter how insightful and potentially correct, is irrelevant. If you violate the code with a metal tipped rocket flown on a low or mid power motor, you will (most likely ) not be allowed to fly it at a NAR CLUB lunch. I am not Tripoli so I don’t know what their ruling will be. Also, if you use a metal tipped nose cone on a low power rocket whether you sneak it in at a sanctioned launch, or if you launch it privately, if something bad happens, and you are a NAR member, most likely NAR insurance will not cover you if you violate the code. Legally anything CAN happen, sanctioned launch or not, but if someone or something gets hurt in an accident, while you are likely to get sued either way, you stand a better chance of coming out of such a suit personally if your launch followed the letter and spirit of the safety code than if you didn’t. Since pretty much every kit and every motor comes with a copy or reference to the code, judges and juries are not likely to be kind or generous to YOU if you violate it, even if the nature of the injury has NOTHING to do with said injury.

Laws and safety codes may or may not make sense to you, and you may have valid arguments. But they are still the standards against which you will be judged when fecal turbine action occurs.

In fact, 'the law is an ass' is from a play published by the English dramatist George Chapman in 1654 - Revenge for Honour:

Ere he shall lose an eye for such a trifle... For doing deeds of nature! I'm ashamed. The law is such an ass.

 

[tab28682]

You are certainly entitled to your opinion, and in this case you make a decent argument that you are right.

doesn’t change the rules. For high power, metal used may be allowed “as necessary” for high power launches. However, high power launches require a waiver and are commonly performed at clubs Where an RSO reviews the rocket for safety and makes a determination of whether the metal is “as necessary” or not.

low power. NAR rule NUMBER 1.

“Materials. I will use only lightweight, non-metal parts for the nose, body, and fins of my rocket.”

https://www.nar.org/safety-information/model-rocket-safety-code/
Your opinion, no matter how insightful and potentially correct, is irrelevant.

......

Note that I am offering an opinion on risk assessment alone that is 100% valid in that context. I could care less if you think it is irrelevant or not. Please note that nowhere did I suggest that anyone violate the NAR safety code.

You may step down from your high horse now.

 

[Steve Shannon]

You are certainly entitled to your opinion, and in this case you make a decent argument that you are right.

doesn’t change the rules. For high power, metal used may be allowed “as necessary” for high power launches. However, high power launches require a waiver and are commonly performed at clubs Where an RSO reviews the rocket for safety and makes a determination of whether the metal is “as necessary” or not.

low power. NAR rule NUMBER 1.

“Materials. I will use only lightweight, non-metal parts for the nose, body, and fins of my rocket.”

https://www.nar.org/safety-information/model-rocket-safety-code/
Your opinion, no matter how insightful and potentially correct, is irrelevant. If you violate the code with a metal tipped rocket flown on a low or mid power motor, you will (most likely ) not be allowed to fly it at a NAR CLUB lunch. I am not Tripoli so I don’t know what their ruling will be. Also, if you use a metal tipped nose cone on a low power rocket whether you sneak it in at a sanctioned launch, or if you launch it privately, if something bad happens, and you are a NAR member, most likely NAR insurance will not cover you if you violate the code. Legally anything CAN happen, sanctioned launch or not, but if someone or something gets hurt in an accident, while you are likely to get sued either way, you stand a better chance of coming out of such a suit personally if your launch followed the letter and spirit of the safety code than if you didn’t. Since pretty much every kit and every motor comes with a copy or reference to the code, judges and juries are not likely to be kind or generous to YOU if you violate it, even if the nature of the injury has NOTHING to do with said injury.

Laws and safety codes may or may not make sense to you, and you may have valid arguments. But they are still the standards against which you will be judged when fecal turbine action occurs.

In fact, 'the law is an ass' is from a play published by the English dramatist George Chapman in 1654 - Revenge for Honour:

I don’t think anyone has been suggesting that metal nosecones or fins may be acceptable for model rockets. That’s clearly against NFPA 1122. My comments were limited to HPR.

 

[BABAR]

On the original topic: Given that cardboard airframes and plastic nose cones have been involved in a fatal accident and have penetrated automotive sheet metal and glass, I do not see any additional risk to people or property with a small metal tip on a nose.

Note that I am offering an opinion on risk assessment alone that is 100% valid in that context. I could care less if you think it is irrelevant or not. Please note that nowhere did I suggest that anyone violate the NAR safety code.

You may step down from your high horse now.

My apologies for misconstruing your context. When I read, “I do not see any additional risk to people or property with a small metal tip on a nose cone,” sounded to me like you are saying that, “It’s okay to do that.” As you have posted, clearly that was not your intent, and I have plopped off my high horse into the horse hockey. Sound like we are clearly on the same page, metal nose cones or nose cone tips are not appropriate for low and mid power rocketry.

you have my best wishes.

 

[icyclops]

I don’t think anyone has been suggesting that metal nosecones or fins may be acceptable for model rockets. That’s clearly against NFPA 1122. My comments were limited to HPR.

No, but a lot of HP flyers try and justify using them...period. For LP, it really does not matter...it is against the safety code and you are right...no NAR launch will allow such an attempt. My opinion and problem is people can justify safety with ballistic examples and blah, blah, blah....As I have said before, just try and justify using that metal tipped nose cone when the personal injury attorneys come knocking....then you can use all the ballistic examples you like....

regardless of what folks ma feel about using metal for structural purposes in HP....fiberglass, wood coatings have been used for years with high altitude success....sorry for the text, just tired of “plastic is as deadly as metal” talk.....

 

[MidOH]

My metal noseconed rockets are for club fields with big boy rules.

Some clubs are plastic nose cones only.

Some clubs say "soft materials only". Sometimes fiberglass fins are frowned upon.

I don't bother swapping cones. I have a dozen paper rockets, and a half dozen fiberglass rockets ready to rock any given weekend. I simply pick the appropriate ones. (And box up the others to)