L3 Certification - NAR vs. TRIPOLI . . . What's Required for Each ?

[Ez2cDave]

I am planning my Level 3 Cert and need some info on the specific differences in the requirements between NAR vs. TRIPOLI.

I'm currently NAR only, but could easily reactivate my Tripoli number.

Thanks, in advance!

Dave F.

 

[Steve Shannon]

Dave,
I recommend you look in the high power Rocketry forum, not the mid-power forum. If you don’t find what you want there, I’d be happy to answer your questions there.

 

[cwbullet]

Moved to High Power. If you report errant posts to the wrong forum, mods will move them.

 

[Steve Shannon]

Here’s a previous thread discussing the same topic:
Tripoli vs NAR
https://www.rocketryforum.com/index.php?threads/Tripoli-vs-NAR.142897/

The procedures are so similar that the real question is usually which you have easier access to, a couple of TAPs or an L3CC. Many TAPs are L3CCs and vice versa. Both organizations have online lists of the TAPs or L3CCs.
Good luck!

 

[Ez2cDave]

Dave,
I recommend you look in the high power Rocketry forum, not the mid-power forum. If you don’t find what you want there, I’d be happy to answer your questions there.

OK . . . Now that we are "in the right place" . . . ( Thanks, Chuck ) !

Item by item and requirement by requirement, what are the differences between NAR & TRIPOLI Level 3 Certification ?

Thanks,

Dave F.

 

[Steve Shannon]

OK . . . Now that we are "in the right place" . . . ( Thanks, Chuck ) !

Item by item and requirement by requirement, what are the differences between NAR & TRIPOLI Level 3 Certification ?

Thanks,

Dave F.

Tripoli:
https://www.tripoli.org/Level3

NAR:
https://www.nar.org/high-power-rocketry-info/level-3-certification/

 

[Bat-mite]

Only ones I can think of are:

TRA - pre-flight need two TAPs / NAR - need one L3CC

TRA - cert flight witness/sign-off by TAP / NAR - witness/signoff by one L3CC and one L2/L3 member

 

[Steve Shannon]

Another difference is that for NAR, the design must be approved before construction begins:
Prior to the start of construction of the Level 3 Certification project, the flyer shall submit detailed plans for L3CC member review and approval. The purpose of the review is to ensure the rocket will be structurally and functionally adequate for the stresses encountered during launch and recovery.

That’s specifically required by NAR. It’s a good idea for both organizations. In general it “appears” that Tripoli leaves more up to the judgement of its TAPs where NAR L3CC members are slightly more procedure driven, but in practice I’ve not seen a difference.

 

[Ez2cDave]

Here’s a previous thread discussing the same topic:
Tripoli vs NAR
https://www.rocketryforum.com/index.php?threads/Tripoli-vs-NAR.142897/

The procedures are so similar that the real question is usually which you have easier access to, a couple of TAPs or an L3CC. Many TAPs are L3CCs and vice versa. Both organizations have online lists of the TAPs or L3CCs.
Good luck!

Steve,

I also read the threads where L3CC's and TAP's arecapriciously throwing in their own "hoops" for rocketeers to jump through, above and beyond NAR or TRIPOLI requirements . . .

I want to verify the following, for BOTH the NAR & TRIPOLI :

(1) Minimum Thrust / Weight ratio is 3:1 ( Per Safety Codes 7 Tripoli "Safe Launch Practices" )

(2) Is one arming switch per altimeter required or can one switch arm the entire system ?

(3) Are the "formally-stated" requirements the only ones that count toward certification?


The NAR openly lists all of the L3CC's on its website . . . TRIPOLI requires Membership to see the list on the website.

How about supplying a list of the TAP's to help me decide ?

In 2005, Mark Canepa provided this handy chart in "Modern High-Power Rocketry 2, although outdated . . . For example the infamous NAR "6-Switch" requirement was in place at that time ( Alt1, Alt2, Drogue Charge 1, Drogue Charge 2, Main Charge 1, Main Charge 2 ) - That was ridiculous and added unnecessary "failure modes" !




Dave F.

 

[Nytrunner]

In practice, mandatory build inspection could have potentially prevented a TRA L3 cert failure earlier this year.

But all is clear in hindsight, and different TAPs have different approval philosphies.

 

[tim cubbedge]

yea, you will find that the certification process can be somewhat subjective.

 

[Bat-mite]

(1) Minimum Thrust / Weight ratio is 3:1 ( Per Safety Codes 7 Tripoli "Safe Launch Practices" )

TAP/L3CC may have to accept 3:1, but site RSO may not approve your cert flight if that T:W ratio is insufficient for the field or the weather.

 

[Steve Shannon]

TAP/L3CC may have to accept 3:1, but site RSO may not approve your cert flight if that T:W ratio is insufficient for the field or the weather.

I doubt you will find many TAPs who accept less than 5:1 initial thrust to weight. 3:1 is taken directly from NFPA 1127, but it says 3:1 average. The real criteria is the speed the rocket is traveling when it leaves the guidance of the launch rail.

 

[Bat-mite]

The real criteria is the speed the rocket is traveling when it leaves the guidance of the launch rail.

Absolutely!

 

[Steve Shannon]

Steve,

I also read the threads where L3CC's and TAP's arecapriciously throwing in their own "hoops" for rocketeers to jump through, above and beyond NAR or TRIPOLI requirements . . .

I want to verify the following, for BOTH the NAR & TRIPOLI :

(1) Minimum Thrust / Weight ratio is 3:1 ( Per Safety Codes 7 Tripoli "Safe Launch Practices" )

(2) Is one arming switch per altimeter required or can one switch arm the entire system ?

(3) Are the "formally-stated" requirements the only ones that count toward certification?


The NAR openly lists all of the L3CC's on its website . . . TRIPOLI requires Membership to see the list on the website.

How about supplying a list of the TAP's to help me decide ?

In 2005, Mark Canepa provided this handy chart in "Modern High-Power Rocketry 2, although outdated . . . For example the infamous NAR "6-Switch" requirement was in place at that time ( Alt1, Alt2, Drogue Charge 1, Drogue Charge 2, Main Charge 1, Main Charge 2 ) - That was ridiculous and added unnecessary "failure modes" !

View attachment 382924


Dave F.

1. Depending on your motor and simulation results, a TAP might allow you to get by with 3:1, but I would expect 5:1.
2. One arming switch in total does not satisfy the electronics redundancy requirement. You need one for each of your electronics systems.
3. No; TAPs and L3CC members may use their judgement.

I’ll bring up the “security” surrounding the TAP list at our next conference call. I think I know why it’s members only. One of the things both organizations try to prevent is “TAP shopping” or “L3CC shopping” which is when a candidate tries to find a TAP or L3CC who allows the candidate to do what they want. If you want to pm me with your location I can tell you who the TAPs are nearest you.

 

[roytyson]

One thing I learned about the arming switches, NAR does not allow wireless switches, they must be physical switches with gaps in current streams. Tripoli allows wireless switches, such as my Eggtimer Protons, as long as the TAPs agree and the flying fields will allow this. I got permission from my TAPs and from Kloudbusters so I have all wifi switches on my L3 build.

 

[Ez2cDave]

1. Depending on your motor and simulation results, a TAP might allow you to get by with 3:1, but I would expect 5:1.

Steve,

My concern on the thrust / weight ratio ( using the "average thrust" of the motor ) is that I want to use an AEROTECH M650W "Moonburner" . . . The flight objectives, other than Certification, are to remain sub-transonic ( below .8 Mach / 900 fps ).

Due to the long "tail-off", typical of a Moonburner, it makes the "usable thrust number" for the M650W look artificially low.

As a "hypothetical" example, a 3:1 maximum weight, "by the numbers" would be 48.7 lb for an M650W ( There is NO WAY I would ever fly that heavy a rocket on that motor, even in perfect weather ) . . . At 5:1, by the numbers", a maximum weight would be 29.2 lb ( Difficult to make that weight in a 7.5" diameter rocket, considering that the motor weighs about 11 lbs., by itself, loaded. )

HOWEVER, in looking at the Thrust Curve, it is plain to see that the motor has plenty of "kick" at ignition and adequate thrust for the first 4.5 seconds or so . . .

Based on a "hypothetical" 48.7 lb rocket, it would be above a 3:1 ratio for the first 4.5 seconds on the burn ( 9.1 second burn time ) . . . BUT, 5:1 would only occur for about the first second of powered flight ( NO WAY ! )

At 29.2 lb, the 3:1 ratio is exceeded up until about 6.5 seconds into the burn . . . 5:1 would be exceeded, until 4.5 seconds into the burn.

Naturally, my L3 project has not been built yet, but I am predicting a nominal maximum liftoff weight of 35 lb ( shooting for less ) . . . . That would exceed 3:1 for 6 seconds of the burn and 5:1 for 4 seconds of the burn. I will be flying off a 12ft. Black Sky Extreme rail.

Motor Data below :

Dave F.

 

[Nytrunner]

BUT, 5:1 would only occur for about the first second of powered flight ( NO WAY ! )

Why "No way"? If your rocket isn't up to stable speed by the 1 second into the flight, you've got bigger problems.

Reasonable reviewers will look at the velocity profile of your rocket

 

[Flyfalcons]

A 7.5" rocket shouldn't have difficulty staying less than transonic on an M with more oomph than that 650. Just running a quick Thrustcurve, a 30 pound 7.5 inch rocket only gets 724fps (mach 0.65) on an M1297W, with a much more comfortable margin off the pad. It seems like you're trying to make the 650 do what it wasn't really meant to do.

 

[Steve Shannon]

It’s that initial kick that gets the rocket off the pad. That’s why I said 5:1 initially. 35 lbs. loaded is pretty light for a 7.5 inch rocket, but I don’t think you need to worry about going supersonic. I think mine was 40#. On an M1297 it went about 5k, but was very easy to see the whole time.
Your TAPs or L3CC are there to help you through all of this also.

 

[JoeG]

My L3 was 7.5" and about 35lbs. M1297 put it at 6200'. Nowhere near Mach. I think around 400+mph but would have to look it up. Like Steve's it was visible all the way and landed not that far away.

 

[rharshberger]

My L3 was 7.5" and about 35lbs. M1297 put it at 6200'. Nowhere near Mach. I think around 400+mph but would have to look it up. Like Steve's it was visible all the way and landed not that far away.

My L3 was 5.38" and 35lbs, 7800' and 700fps ( iirc), its amazing how much difference that 2" of diameter makes. It was visible all the way up and down.
I did my cert NAR but my L3CC was also a TAP, most if not all of my choices for L3CC "locally" are also TAPS. One thing about NAR L3 certs is that they dont expire if your membership lapses, TRA's certs lapse after a certain amount of time if you let your membership lapse (2 years?).

 

[OverTheTop]

L3 certification is a bit subjective. Work with your TAP/L3CC people as to what they want from you. If you are unhappy you can try other people to certify you with the relevant flight. For example, some TAP/L3CC want to be able to see the entire flight, so MD flights out of sight are not acceptable, even though data would show the sink rates and validate recovery performance. It is a personal thing, on top of the official requirements. You could try and negotiate otherwise, but that may not lead to a successful outcome and just add to the stress.

 

[Ez2cDave]

One thing about NAR L3 certs is that they dont expire if your membership lapses, TRA's certs lapse after a certain amount of time if you let your membership lapse (2 years?).

I knew that cert levels "go away" in Tripoli, for lapsed membership of ONE YEAR.

However, Cert Levels can be transferred from TRIPOLI to NAR and vice-versa . . .

https://www.tripoli.org/CertificationFAQ

QUOTE :

"note: If you allow your TRA membership to expire, your certification will be reset to Level 0 one year after the expiry of your membership. When a members certification has reset, you will be required to re-fly/re-sit exams as any other member who wishes to obtain the certification level.

What do I need to do to get my NAR certification level transferred to Tripoli?

Send a copy of your NAR card showing current member status and NAR cert level. Mail a copy to HQ, or fax a copy to HQ, or scan and email a copy to HQ.

END QUOTE :

https://www.nar.org/high-power-rocketry-info

QUOTE :

"Cross Certification

NAR members who are currently Tripoli Rocketry Association HPR certified may cross-certify with NAR at the same level by completing the identification portion of a NAR high power application and attaching proof of current Tripoli certification (e.g., photocopy of Tripoli consumer confirmation card) to NAR headquarters with a request that their certification level be updated.

NAR HPR certifications, once earned, are valid whenever NAR membership is current, and are reinstated after membership lapses."

END QUOTE :

Dave F.

 

[rharshberger]

I knew that cert levels "go away" in Tripoli, for lapsed membership of ONE YEAR.

However, Cert Levels can be transferred from TRIPOLI to NAR and vice-versa . . .

https://www.tripoli.org/CertificationFAQ

QUOTE :

"note: If you allow your TRA membership to expire, your certification will be reset to Level 0 one year after the expiry of your membership. When a members certification has reset, you will be required to re-fly/re-sit exams as any other member who wishes to obtain the certification level.

What do I need to do to get my NAR certification level transferred to Tripoli?

Send a copy of your NAR card showing current member status and NAR cert level. Mail a copy to HQ, or fax a copy to HQ, or scan and email a copy to HQ.

END QUOTE :

https://www.nar.org/high-power-rocketry-info

QUOTE :

"Cross Certification

NAR members who are currently Tripoli Rocketry Association HPR certified may cross-certify with NAR at the same level by completing the identification portion of a NAR high power application and attaching proof of current Tripoli certification (e.g., photocopy of Tripoli consumer confirmation card) to NAR headquarters with a request that their certification level be updated.

NAR HPR certifications, once earned, are valid whenever NAR membership is current, and are reinstated after membership lapses."

END QUOTE :

Dave F.

I was pointing that out just in case you were not a member of both, or others who are not aware. [emoji3]

 

[Steve Shannon]

I call that NAR certification insurance.

 

[Ez2cDave]

I call that NAR certification insurance.

Steve.

So, if Tripoli Members transfer their cert levels to NAR, allow their Tripoli memberships to lapse for a few years, and then reactivate their old Tripoli number, they get all of their Tripoli Cert levels back, simply by transferring them back to Tripoli, from NAR ?

Why not just make Tripoli Cert levels "lifetime", too ?

Dave F.

 

[Ez2cDave]

I was pointing that out just in case you were not a member of both, or others who are not aware. [emoji3]

Rich,

I knew that . . . I just added the text from both organizations, in one location.

Thanks,

Dave F.

 

[Steve Shannon]

Steve.

So, if Tripoli Members transfer their cert levels to NAR, allow their Tripoli memberships to lapse for a few years, and then reactivate their old Tripoli number, they get all of their Tripoli Cert levels back, simply by transferring them back to Tripoli, from NAR ?

Why not just make Tripoli Cert levels "lifetime", too ?

Dave F.

I know that if I go too long without flying, I’ve lost some expertise. Personally, I think it was a mistake for NAR to make certs lifetime, and we don’t want to make the same mistake, but at the same time the only people who don’t have lifetime certs are Tripoli members who don’t belong to NAR. I wish knew exactly the right thing to do.

 

[Ez2cDave]

I know that if I go too long without flying, I’ve lost some expertise. Personally, I think it was a mistake for NAR to make certs lifetime, and we don’t want to make the same mistake, but at the same time the only people who don’t have lifetime certs are Tripoli members who don’t belong to NAR. I wish knew exactly the right thing to do.

Steve,

Well, since Tripoli currently allows cert levels to be transferred to NAR and vice-versa . . . Cert levels, essentially, already are "lifetime", since all someone has to do is join or re-join Tripoli, transfer lifetime NAR levels over and "bingo" the levels are all back, like they never left. NAR made them "lifetime" to "poke Tripoli in the eye with a stick", by making it look like Tripoli was only interested in the money coming in and was "holding members hostage", by de-certifying members who left Tripoli ( cash flow stops ) and later came back.

My suggestion is this . . .

NAR only accepted HPR because TRIPOLI was starting to decimate the NAR Membership, as people who wanted to fly motors larger than a "G" flocked to Tripoli, while being threatened by the NAR.

Now, in the same vein, the "lifetime certifications" need to be embraced by Tripoli, as well.

Have you ever read this article ? . . . It's eye-opening !

https://www.skybusters.org/NOTRA/The LDRS Story.pdf

Dave F.