Certification Pass or Fail

[rcktnut]

sigh. Fine. I'll accept it was sarcasm.

Seriously, all good.

Thank you, any possibility that you can resurrect your build thread on your pail rocket?

DAllen: I remember that you or one of your partners had a very extensive build thread on the Porta-Potty many pics. etc. thru the whole process, including the sub scales, any chance you could resurrect that? BTW your Porta-Potty flight was not my first choice, could not find a video of KY Michaelsons Porta-Potty flight until now. LDRS was the key word.
You should be proud, excellent flight wise as compared to thee Rocketman himself!!
Both threads would be great to see again, take my mind off my over emphasizing my opinion in this thread.
I have to start a resurrection thread on good old builds of the past!!

 

[Steve Shannon]

Seems the bottom line is that there is no bottom line.

again
from NAR high power code

1. Materials. I will use only lightweight materials such as paper, wood, rubber, plastic, fiberglass, or when necessary ductile metal, for the construction of my rocket.

here’s what I stole from Tripoli safety code 1-3 Model Rocket definition

It has structural parts made of paper, wood, or breakable plastic, it has a means for returning it to the ground so it can be flown again; and its primary use is for purposes of education, recreation, and sporting competition.

well shoot, the motor casings are NON-ductile metal, the screw eyes and bolts and nuts and swivels are metal, and sure as heck the BBs in the nose cones aren’t ductile.

while the NAR wording is actually crystal clear (no non-ductile metal), the APPLICATION is equally clearly subjective as LOTS of non-ductile metal parts ARE clearly allowed. Also probably a bit inconsistent as clearly in @sr205347d case the evaluators passed the rocket and many seasoned people here are of different opinions.

not sure if Tripoli is better or worse, they throw in word “structural”…. again what determines whether a part is “structural” or not? The answer is there is no “what” that determines it, there is a “who”, and that is the RSO for regular flights and the certifying official for cert flights. In other words, completely subjective. (A big hunking steel screw eye holding a nose cone full of a few lbs (or more) of BBs sure seems structural to me. (Then again, I am an L-0!))

point is not that these rules are vague or bad, in fact experience has shown they are EXCELLENT as demonstrated by a fantastic safety record that beats many other hobbies (maybe not stamp collecting.). We have professional organizations that come up with these subjective rules, create a culture of safety first, fun second, and we deputize RSOs and evaluators to use their best judgement in applying these rules. Because human judgement is involved, almost by definition things will be inconsistent at times, and that’s okay too. For the most part it works, although the previous post to this (posted during my authoring this diatribe) has a point.

seems like the most consistent advice to would-be L-1s, 2s, and 3s is to know who will be the certifying officials and get their input BEFORE THE BUILD, at least if it is anything but a kit built stock.

1. The TUSC (Tripoli Unified Safety Code) has several sections. The Model Rocket section rules don’t apply to High Power Rockets and the High Power sections has rules that don’t apply to Model Rockets.
2. Later in the TUSC, copper and aluminum are specified as ductile metals.
3. We would love to have you attend a Tripoli launch sometime, hopefully one I’m at, although those are fewer now than a few years ago.

 

[BABAR]

I absolutely hate this guidance, and here's why. You're advocating someone build a one-off certification rocket, something that they may never care about or fly again, and something that may well be unlike something they actually plan to fly.

To me, a certification rocket should be the kind of rocket the flier enjoys. If you're a minimum diameter, performance flier, then build a certification rocket accordingly. If you like big, slow rockets, then that's what your certification rocket should be.

Demonstrate that you've got a clue about how to move on to the next level of the type of flying you like to do. Don't merely check a box and do the minimum effort.

If I'm someone who likes minimum diameter, high performance rockets, how does my Level 3 on a stack of 5 gallon buckets demonstrate anything about my readiness to shove an N5800 in a minimum diameter rocket? It doesn't.

It's no difference if someone does Level 1 on an H128 in a 4" airframe and their next flight is a minimum diameter 38mm with an I600.

-Kevin

Interesting points.

1. Would you at least agree that for a certification build, if a flyer is going to go “off-script” and build something eloquent rather than a stock basic minimum requirement kit, he or she should run it by the appropriate NAR or Tripoli approval authority BEFORE starting the build?

2. I like the idea of “build something you’re gonna want to fly more than once.” On the other hand, if a flyer’s “dream rocket” for that level has something a few leagues off “nominal” (like breakaway fins, or a helicopter recovery ) that might not be the best choice for a certification attempt, or at least should prompt the flyer to seek counseling (for the build plan, not necessarily for himself or herself!)

3. RE: Jumping from a 4” H to a min diameter I.

We had a saying at the Air Force Academy, “ if the minimum wasn’t the minimum it wouldn’t be the minimum.” Some people are always gonna put as little effort as allowed to get the cert and then push the top of the envelope. The (or at least A) safety factor is that the flyer still has to get that min diameter I past the RSO, at least at a club sanctioned launch (which given HPR generally requires a waiver [ @burkefj has some notable exceptions] most HPR flights are done in this setting.). Puts a lot of responsibility on the people signing off the flight cards to ask not only about the rocket but about the experience of the flyer. Fortunately nobody wants to be remembered as the guy who signed off that flight that went totally catywampus and ended up on the evening news with a gazillion YouTube hits.

I think the NAR president (or somebody else important) commented on an unacceptable percentage of “off-nominal “ HPR flights at last big event in a recent Sport Rocketry issue. I will always remember my one NSL attendance where a pretty big rocket did a vertical 360 plus loop around 100 feet AGL before (fortunately) heading DOWNrange. My underwear stayed white (mostly), not sure about the flyer’s or the RSO’s!

Yet another reason excuse for me to stay L-0! Even then, I have to remember that, aside from Darwin Award power line incidents, I think the only death attributed to model rocketry was NOT from a HPR rocket.

 

[troj]

Thank you, any possibility that you can resurrect your build thread on your pail rocket?

This one?

Or are you interested in another variant of it? I have some ideas....

-Kevin

 

[troj]

Interesting points.

1. Would you at least agree that for a certification build, if a flyer is going to go “off-script” and build something eloquent rather than a stock basic minimum requirement kit, he or she should run it by the appropriate NAR or Tripoli approval authority BEFORE starting the build?

2. I like the idea of “build something you’re gonna want to fly more than once.” On the other hand, if a flyer’s “dream rocket” for that level has something a few leagues off “nominal” (like breakaway fins, or a helicopter recovery ) that might not be the best choice for a certification attempt, or at least should prompt the flyer to seek counseling (for the build plan, not necessarily for himself or herself!)

3. RE: Jumping from a 4” H to a min diameter I.

We had a saying at the Air Force Academy, “ if the minimum wasn’t the minimum it wouldn’t be the minimum.” Some people are always gonna put as little effort as allowed to get the cert and then push the top of the envelope. The (or at least A) safety factor is that the flyer still has to get that min diameter I past the RSO, at least at a club sanctioned launch (which given HPR generally requires a waiver [ @burkefj has some notable exceptions] most HPR flights are done in this setting.). Puts a lot of responsibility on the people signing off the flight cards to ask not only about the rocket but about the experience of the flyer. Fortunately nobody wants to be remembered as the guy who signed off that flight that went totally catywampus and ended up on the evening news with a gazillion YouTube hits.

I think the NAR president (or somebody else important) commented on an unacceptable percentage of “off-nominal “ HPR flights at last big event in a recent Sport Rocketry issue. I will always remember my one NSL attendance where a pretty big rocket did a vertical 360 plus loop around 100 feet AGL before (fortunately) heading DOWNrange. My underwear stayed white (mostly), not sure about the flyer’s or the RSO’s!

Yet another reason excuse for me to stay L-0! Even then, I have to remember that, aside from Darwin Award power line incidents, I think the only death attributed to model rocketry was NOT from a HPR rocket.

Regarding checking in advance - for Level 3, a flier should always check before buying parts/starting the build. Even if they plan to build a kit stock. For Level 1/Level 2, if you're going to do something unique, then it's a good idea, but not required. But if they don't, they need to be prepared for the cert authority to decline to permit a cert flight using the rocket.

-Kevin

 

[Orestes Mayo]

I get that vibe from certain flyers, but not from most. Or from the organization. All of them are just toys when compared with real rockets.

And I've never been to a launch that wasn't set up for all low impulse levels. Have a look at these flight statistics for LDRS 39, there were as many C flights as K flights. At a glance, it looks like an easy 25% of the total # of flights were F and under:

View attachment 615441

This makes me happy. I have gotten more involved with MPR in the last 3 months and will be flying for my L1 in December but still love both building and flying LPR in the park. It is afterall what got most of us into this in the first place.

 

[Orestes Mayo]

Must be another NAR thing as Tripoli does not allow helicopter, glider, tumble, ect ect, must be standard parachute recovery for a cert flight

Not a NAR thing. Maybe some clubs do it.

 

[SolarYellow]

It's probably a good idea to fly a cert rocket on motors just below the line a couple times before going for the cert. i.e., if you're going to cert with a baby or modest H, fly a G80 or two before putting that H in it. Make sure you've got multiple nominal flights on the bird before the "big show." Not just working once, but working consistently. With your prep procedures and accompanying check list dialed in.

 

[Ronz Rocketz]

Agree 100% The cert team has spoken ability has been proven.
With the rainbow fish rocket the fins/ sustainer snagged the chute that deployed just fine. Rocket had a bit of horizontal flight to it. No damage to rocket.
The one with the fin issue, was designed to do just what it did, everybody objecting to the results is saying the result was due to too small of a chute resulting in to fast of a decent rate. OP said it was a 36 in. chute, which is more than sufficient for that weight of a rocket including the weight added by the 3D printed add ons. Decent rate, chute sufficient. Fin reattached easily for another flight.

Rainbow fish deployment:

View attachment 615525

The video shows that the chute ejected but didn't deploy because it got snagged causing the rocket to descend at an unsafe rate, IMHO. However as you mention, that's up to the discretion of the certification team.

The checklist doesn't say the chute has to deploy, just that it has no damage.

Does the recovery system being used follow the requirements of an Active Recovery deployment system required for
certifying? Inspect the recovery system. Verify that the shock cord is not cut or frayed and is free of burns. Are the shock
cord mounts securely mounted to the model? Are sharp edges present which may cut shock cords, parachute risers, and
suspension lines? Is hardware, e.g. swivels, screw eyes, sufficiently strong to withstand recovery loads. If required, perform
a pull test on the recovery system. Is parachute protection (e.g. wadding) adequate? Check for parachute damage, e.g.
tears, burns, which may spread during recovery.

As the rocketeer carries the rocket away, it appears to be in one piece so difficult for me to say if there was any damage. I did witness a Level 1 attempt where the NC separated because the rocketeer used a single knot to attach the cord to the eyelet. No damage to the rocket and flew again successfully and then later for its Level 2. My question is, is it more important for the rocket to function as intended in a safe manner, or is it more important that the rocket suffered no significant damage?

 

[BABAR]

. My question is, is it more important for the rocket to function as intended in a safe manner, or is it more important that the rocket suffered no significant damage?

no brainer. Safety is always paramount.

I would expect an official to fail any flight where there was any evidence of unsafe performance, regardless of a pristine condition of rocket post flight. Whereas “significant damage” is subjective.

you can always repair or replace a damaged rocket. Safety violations, or more specifically the potential CONSEQUENCES of safety violations, may not ”buff out” easily if at all.

 

[Ronz Rocketz]

no brainer. Safety is always paramount.

I would expect an official to fail any flight where there was any evidence of unsafe performance, regardless of a pristine condition of rocket post flight. Whereas “significant damage” is subjective.

you can always repair or replace a damaged rocket. Safety violations, or more specifically the potential CONSEQUENCES of safety violations, may not ”buff out” easily if at all.

I agree. I feel that NAR/TRA should emphasize this more in the certification process, especially in the NAR checklist which appears to be more focused on the condition of the rocket before the flight instead of the actual results. I apologize for my sacrilegious language.

Now if we're talking about disposing of suspect A10 motors, that's a different matter.

 

[KenECoyote]

 

[Rschub]

I demand you certify me.

 

[tsmith1315]

I demand you certify me.

None shall pass!

 

[sharkbait]

Not a NAR thing. Maybe some clubs do it.

Actually it is a NAR thing, I am educating myself on the NAR cert rules, it says must be active recovery, please read the NAR definition of active recovery, which includes but limitited to parachutes, stresmers, helicopter, R/C controls ect ect

Tripoli is crystal clear, parachute recovery that’s all

 

[rcktnut]

While we are at it here's another to contemplate: It passed with about a 1.5 in. zipper.

 

[Troy3003]

While we are at it here's another to contemplate: It passed with about a 1.5 in. zipper.

That one should have never passed. There are plenty of examples I’m sure. Some of the guys probably need to firm up their passing standards. It’s pretty cut and dry now, not much interpretation needed.

 

[Buckeye]

While we are at it here's another to contemplate: It passed with about a 1.5 in. zipper.

Nope. Faulty motor and zipper. Fail.

 

[TheTank]

Nope. Faulty motor and zipper. Fail.

Faulty motor… or drilled incorrectly which would also be another reason for a fail in my book. Ive never seen a DMS motor pop that early into the burn before. Not a motor defect I have ever seen.

 

[-Slick-Ice]

3. RE: Jumping from a 4” H to a min diameter I.

Although it wasn't a minimum diameter, I did my L1 on a 3" with the H135 that everyone suggested. I should have just used the I180 that I like way better. It's like a 2% "I" motor with way better initial thrust "but it's a reload and shouldn't be used for your L1"

 

[Ronz Rocketz]

While we are at it here's another to contemplate: It passed with about a 1.5 in. zipper.

NAR says that minor zippering is okay if the NC can go back on it and relaunch. Assuming the shoulder is 1.5in, possible. It looked beautiful coming down, but I agree, who's to say it wasn't an incorrect drilling. It's 1/8in per second, right?

Actually it is a NAR thing, I am educating myself on the NAR cert rules, it says must be active recovery, please read the NAR definition of active recovery, which includes but limitited to parachutes, stresmers, helicopter, R/C controls ect ect

Tripoli is crystal clear, parachute recovery that’s all

True. My point is that it says parachute recovery. It doesn't say the parachute has to fully deploy, only that it has to come down at a safe speed.

 

[Steve Shannon]

It's 1/8in per second, right?

You know that’ll stick in some poor rocketeers head, right?

For those who don’t know, it’s 1/32” per second.

 

[Ronz Rocketz]

You know that’ll stick in some poor rocketeers head, right?

For those who don’t know, it’s 1/32” per second.

I know. My bad, but that could be why the motor popped early.

@KenECoyote
Duct tape is the handyman's tool!!!

 

[BABAR]

For those who don’t know, it’s 1/32” per second.

Hmmm. not sure if this is a helpful mnemonic, but earth gravity is 32 feet per second squared

 

[Voyager1]

… "but it's a reload and shouldn't be used for your L1"

Why?

 

[-Slick-Ice]

Because they need to watch you assemble seemed to be the biggest reason. They were actually right about something though. I wouldn't have had time to try again if I had to clean the case since it was getting close to the end of the day.

 

[sharkbait]

NAR says that minor zippering is okay if the NC can go back on it and relaunch. Assuming the shoulder is 1.5in, possible. It looked beautiful coming down, but I agree, who's to say it wasn't an incorrect drilling. It's 1/8in per second, right?


True. My point is that it says parachute recovery. It doesn't say the parachute has to fully deploy, only that it has to come down at a safe speed.

This is really really stretching it. How many people pack or position their chutes so they get ejected but do not open and are sized such that there is still a safe decent rate and landing with a balled up or fouled chute,? You might as well save some money and ball up a pair of underwear and stuff them in a sock and tie it on your nose cone. Again, beyond safety, the purpose of the cert process is to show your competency of flying bigger, heavier rockets with larger more powerful motors. I am not belittling L1 but if you don’t learn proper recovery techniques like proper chute packing, harness management, and chute positioning location with a small L1 bird where even with recovery system failure can still sometimes bring a rocket down and not get damaged then you will not be prepared for larger rockets that are Not forgiving or safe to descend without fully deployed chutes,

 

[Ronz Rocketz]

This is really really stretching it. How many people pack or position their chutes so they get ejected but do not open and are sized such that there is still a safe decent rate and landing with a balled up or fouled chute,? You might as well save some money and ball up a pair of underwear and stuff them in a sock and tie it on your nose cone. Again, beyond safety, the purpose of the cert process is to show your competency of flying bigger, heavier rockets with larger more powerful motors. I am not belittling L1 but if you don’t learn proper recovery techniques like proper chute packing, harness management, and chute positioning location with a small L1 bird where even with recovery system failure can still sometimes bring a rocket down and not get damaged then you will not be prepared for larger rockets that are Not forgiving or safe to descend without fully deployed chutes,

I totally agree, but that's not what I'm reading in the NAR checklist that I quoted and in the Active Recovery definition below. IMHO, if the chute doesn't deploy, then that's an automatic fail (to quote Dredd) with all due respect to @rcktnut (who I suspect was present if not involved in the Rainbow Fish certification?). If so, then I apologize to @rcktnut because it's a great video... I just disagree with the conclusion.

There are some ambiguous terms in the definition such as "dramatically reduces the vertical descent rate" and "safely recovering the rocket". Also, what is the definition of "deployed"? In the end, it's up to the cert team to make the judgement call as @rcktnut mentioned in post #150.

DEFINITION: Active Recovery is the deployment of a primary recovery device that actively changes the physical configuration and dramatically reduces the vertical descent rate of the rocket model when deployed. This device must be of sufficient size, based on the weight of the model, so that the device is capable of safely recovering the rocket. The active recovery device can include parachutes, streamers, helicopter devices, R/C control and any other devices that are physically deployed to provide safe recovery of the model.

 

[MikeT]

While we are at it here's another to contemplate: It passed with about a 1.5 in. zipper.

I would have failed that one.

 

[sharkbait]

I totally agree, but that's not what I'm reading in the NAR checklist that I quoted and in the Active Recovery definition below. IMHO, if the chute doesn't deploy, then that's an automatic fail (to quote Dredd) with all due respect to @rcktnut (who I suspect was present if not involved in the Rainbow Fish certification?). If so, then I apologize to @rcktnut because it's a great video... I just disagree with the conclusion.

There are some ambiguous terms in the definition such as "dramatically reduces the vertical descent rate" and "safely recovering the rocket". Also, what is the definition of "deployed"? In the end, it's up to the cert team to make the judgement call as @rcktnut mentioned in post #150.



View attachment 615700

I guess we can mince words and lawyer this thing till the cows come, but bottom line is parachutes are put in rockets to fully deploy or (fully inflate) to bring the rocket back to earth in a controlled manner at a safe descent rate.
Rules and guidelines are almost never worded as such that they are 100% fool proof or subject to some manipulation of gray areas but the cert team or cert person should not be passing flights that do not show proper recovery whether the rocket is damaged or not.

I agree with you on the rainbow fish, the girl obviously put a lot of time and effort into that project but it should have failed, my experience is that a person that shows that much energy and dedication would learn more from a fail than a pass and find that correcting the problems and achieving success on the next go round is even more gratifying.