Staying under level one certification

Please forgive me if this has been asked before but I am having trouble finding specific clarity:
As I am not level one certified just yet here is my Q.
I have Aerotech 20/40-120 RMS cases, if I were to build a twin 29mm setup, say in a Minie Magg, could I fly 2 G53FJs and still be ok without Level one cert?
The Minie can be built under 1500G weight, just barely
the G53 has 60 grams of propellant and 53N of average thrust
so -
3.3lb rocket
120 grams of propellant (in 2 separate motors)
106N average thrust (but again in 2 separate motors)

thanks all for your thoughts here - I have no intention of starting this build if I would be breaking any rules (I would not be able to fly it legally at my club and of course will not risk putting them in jeopardy in any way)

CoachSteve said:

Please forgive me if this has been asked before but I am having trouble finding specific clarity:
As I am not level one certified just yet here is my Q.
I have Aerotech 20/40-120 RMS cases, if I were to build a twin 29mm setup, say in a Minie Magg, could I fly 2 G53FJs and still be ok without Level one cert?
The Minie can be built under 1500G weight, just barely
the G53 has 60 grains of propellant and 53N of average thrust
so -
3.3lb rocket
120 grains of propellant (in 2 separate motors)
106N average thrust (but again in 2 separate motors)

thanks all for your thoughts here - I have no intention of starting this build if I would be breaking any rules (I would not be able to fly it legally at my club and of course will not risk putting them in jeopardy in any way)

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I think you mean grams of weight for your motors, rather than grains.
Assuming each is 60 grams, that’s 120 grams. If the Minnie is already almost 1500 grams (say 1400) the total ends up at 1520 (1400 + 120 = 1520) so there must be a waiver.
But your two motors don’t add up to 320 Newton seconds of impulse and neither one exceeds 160 N-s, so you would not need to be certified.
I’m answering from memory, so maybe someone will catch me in a mistake.

2x g76g in the same case may be a better choice, dramatically more leap off the pad. Harder to ignite though, but I've not had trouble with 'em.

You should be able to cut the weight if you stick to woodglue, cut the glassine, maybe hole & skin the fins ( if necessary ).

I am for sure thinking of ways to "lighten up" the minie - if needed
So, for the rocket weight - to be under the 1500G cert weight - does that mean the rocket or the rocket plus 2 fully loaded RMS setups?
the F53FJ reload weighs more that 60G of course, that 60g is just the actual propellant

Total weight Ready to Fly.

CoachSteve said:

I am for sure thinking of ways to "lighten up" the minie - if needed
So, for the rocket weight - to be under the 1500G cert weight - does that mean the rocket or the rocket plus 2 fully loaded RMS setups?
the F53FJ reload weighs more that 60G of course, that 60g is just the actual propellant

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My first attempt at G76's was not a success-


The second was.... barely...



If you do it, long long long ignitor leads are a good idea. if one motor takes off, it'll rip the other igniter out as the rocket lifts off if you anchor them normally.


Personally, you can't beat two G80T's for this setup. They light easy and lift like crazy. In the 29 40-120 case I'd honestly use F50T's. they light right up.

Keeping a mini mag under 1500 loaded is trick. you may have to cut out the bottom of the nosecone.... and drill out the rear CR to lighten things.

So it sounds like 2 hobby line G reloads, when used together, is below level one requirements but a fully loaded Minie under 1500 is near impossible, considdering 2 built 29/40-120 motors is around 200g.

I think you might be surprised at how much weight you can trim out.

I've got a Big Daddy that's actually less than the hangtag weight. Wood hardener to stiffen the tube and sand down fuzzies after pulling the glassine.

You don't actually need the MMTs either, if you do the CR throughholes a little tight.

Not sure but I think you might be confusing HPR Level 1 with FAR 101 or possibly NFPA 1122 Model rocket definition (1500g or less, 125g of propellant or less, and less than 160ns of thrust). HPR is under NFPA 1127 and covers rockets that do not meet the desciption in parentheses.

rharshberger said:

Not sure but I think you might be confusing HPR Level 1 with FAR 101 or possibly NFPA 1122 Model rocket definition (1500g or less, 125g of propellant or less, and less than 160ns of thrust). HPR is under NFPA 1127 and covers rockets that do not meet the desciption in parentheses.

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I think what Rich is trying to say is that the weight of the rocket doesn't have anything to do with L1--other than a heavy rocket is hard to lift with sub-L1 motors. The only thing that separates an L1 from a non-L1 flight is the propellant weight. <2 x G80 and you are below L1.

I had supposed the OP was saying " I want to fly correctly without an L1 " AKA FAR101 compliant. I could be wrong, wouldn't be the first time today.

Unfortunately, the definition of class 1 and 2 rockets according to FAR 101 and the boundary between model rockets/high power as delineated by NFPA 1122 and NFPA 1127 do not align at the bottom end. Class 2 rockets require a COA (waiver). It’s possible to have a high power rocket that doesn’t require a waiver. It’s also possible to have a Class 1 rocket (no waiver required) that requires high power certification to buy and use the motor. Different authorities have imposed different rules.

BDB said:

I think what Rich is trying to say is that the weight of the rocket doesn't have anything to do with L1--other than a heavy rocket is hard to lift with sub-L1 motors. The only thing that separates an L1 from a non-L1 flight is the propellant weight. <2 x G80 and you are below L1.

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Thank you, many distractions going on during the typing of that post.....4 year old, 8 year old, and 10 year old....

I think we have answered the OP's question... but just to make sure

POWER and WEIGHT are where the lines are that we don't want to cross.

For Level Zero maximum power we can fly as much as 2x G80 power. No cert required.
- The hard part is getting both to light simultaneously.

The rocket becomes FAA Class 2 (with L1 Cert required) when the TAKE-OFF weight exceeds 1500 grams or 3.3 LBS or aprox. 53 oz.

The Minie-Magg is a cool rocket My personal recommendation is to build ALL rockets as light as possible. After all, these are rockets not boat anchors.
I would keep it 38mm instead of 2x29. Then all you need is a membership - TRA or NAR if you are in the USA. $30 bucks for a DMS H motor, and someone to sign the cert paperwork.

After you cert, you can build a second Minie-Magg with 2x29 motors... and fly it even if it does weigh-in over the limit

Thank you all for the clarity - seems like the question was worth asking
My current situation is that I have the 29/40-120 hardware - and the reloads
if I jump to 38mm, I need hardware, must get certified, and most reloads require hazmat
I just don't know if I can build a Minie, loaded with 2 29 RMS setups under the weight limit
maybe I get the kit, mod the parts for my idea, weigh it all out, if it doesn't meet the requirement I relegate it to the build pile for the day that I jump to level 1.
With all the hubbub around Lakewood trying so hard to shut CRASH down, the jump to cert may not be in the cards however, thus my reluctance to jump into 38mm hardware and all

CoachSteve said:

if I jump to 38mm, I need hardware, must get certified, and most reloads require hazmat

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there are single use 38mm H motors, 38/120 G motors, and H and higher reloads that don't require hazmat. the Loki 38/120 case has 4 nice G motors and no haz

solid_fuel said:

there are single use 38mm H motors, 38/120 G motors, and H and higher reloads that don't require hazmat.

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There are? SU 38 mm non-hazmat? I’ve never seen any, but I’d love to be able to order them. Can you show me where? I looked again, still can’t find any.

Sorry. Maybe those should have been periods instead of commas.

Well, darn.

We are really lucky to have Wildman as our home-field vendor. We have to drive about an hour to the launch site, but we don't have to pay hazmat fees.

Coach Steve... Is Apogee Components - a reasonable drive from your location? Maybe you can place an order and pick it up at the store to save on hazmat. - just a thought

Apogee is about 1.5 hours away - not too bad.
thanks for the reminder.
I think i am going to accept the challenge and see if I can build a Magg loaded under 1500G
I will post the build thread for all to see - thanks all for the answers to my questions - here we go

Well shoot. What if we had a Minie Magg with 1/8" fins, rings and a few 29mm holes in it? This just might set my ADD off today...

I've flown my LOC IV with an G79 using a 38mm-29mm. It came in under 3.3lbs loaded. Maybe flying it that way would work for you.

I think the summary below is not exactly right.

Sabrina said:

POWER IMPULSE and WEIGHT are where the lines are that we don't want to cross.

For Level Zero maximum power impulse we can fly as much as 2x G80 power impulse. No cert required.

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HPR cert is required when:

• Any one motor exceeds 160 Ns;
• The sum of all motors (clusters, staging, anything else using more than one) exceeds 320 Ns; or
• Average thrust exceeds 80 N. I thought that was total, but if 2×G80 is OK then I guess it must be per motor.

The rocket becomes FAA Class 2 (with L1 Cert required) when the TAKE-OFF weight exceeds 1500 grams or 3.3 LBS or aprox. 53 oz.

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According to Steve, Class 2 does not necessarily require any HPR cert.

And there's also the limit on propellant mass, 125 g, which I think applies to HPR certification rather than FAA class, and I think is total rather than per motor, but I'm not sure I'm remembering that right and I'm feeling too lazy at the moment to look it up.

According to ThrustCurve.org:

• The G80's impulse is 132.2 Ns, so two of them together come in at 264.4 Ns and would be OK with no cert. But a single motor at 264 Ns would not.
• The average thrust is actually 86.7 N, so it's over the limit. But I've heard before about it being considered mid power based on its labeled thrust. I don't know how they get away with that.
• The propellant mass is 63 g, so two of them together gives 126 g, which exceeds the limit.

So your proposed setup may remain Class 1 if you can lighten it enough (which will be challenging.) But it looks to me like 2×G80 should require L1 cert regardless of the liftoff mass due both to average thrust and total propellant mass.

Steve Shannon is our resident expert on these regulatory matters.

My intent is to go with 2XG53Fjs
G53 has 60 grams of propellant and 53N of average thrust
so 120g total and 106N thrust

jqavins said:

I think the summary below is not exactly right.HPR cert is required when:

• Any one motor exceeds 160 Ns;
• The sum of all motors (clusters, staging, anything else using more than one) exceeds 320 Ns; or
• Average thrust exceeds 80 N. I thought that was total, but if 2×G80 is OK then I guess it must be per motor.

According to Steve, Class 2 does not necessarily require any HPR cert.

And there's also the limit on propellant mass, 125 g, which I think applies to HPR certification rather than FAA class, and I think is total rather than per motor, but I'm not sure I'm remembering that right and I'm feeling too lazy at the moment to look it up.

According to ThrustCurve.org:

• The G80's impulse is 132.2 Ns, so two of them together come in at 264.4 Ns and would be OK with no cert. But a single motor at 264 Ns would not.
• The average thrust is actually 86.7 N, so it's over the limit. But I've heard before about it being considered mid power based on its labeled thrust. I don't know how they get away with that.
• The propellant mass is 63 g, so two of them together gives 126 g, which exceeds the limit.

So your proposed setup may remain Class 1 if you can lighten it enough (which will be challenging.) But it looks to me like 2×G80 should require L1 cert regardless of the liftoff mass due both to average thrust and total propellant mass.

Steve Shannon is our resident expert on these regulatory matters.

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Thanks Joe!, I'm real sorry if my posting was inaccurate. I totally don't want to promote incorrect or misleading facts/ideas. I have read through NFPA 1122, 1125, and 1127 about 2000 times (really, I'm not kidding ) and I thought I understood things correctly. I have no problem being wrong, I make mistakes all the time. Thanks for correcting me !.

With FAR 101 and NFPA and the CPSC and safety codes from NAR and TRA etc. -the whole alphabet of rules and regs, it can be confusing and intimidating.

I'm still a bit puzzled by one of the things you corrected me on. Are you saying that it's possible for a rocket to fall under FAA class-2 under 14 CFR part 101, and an un-certified person (level 0) would be allowed to launch it at a NAR or TRA launch? (excluding a cert flight of course)

Based on my reading and understanding of NFPA 1127 3.3.13.1 it seems really clear that as soon as the 1500 gram limit is exceeded, regardless of the motor used (a G motor for example) the rocket is classified as "High Power" in NFPA and becomes FAA Class-2 as well. NFPA 1127 4.2 clearly requires a certified user to launch anything classed as "High Power" regardless of the motor not requiring certification for purchase.

I must be missing something, and the details always hold the key -So my question... what kind of FAA Class-2 rocket could be launched by an uncertified user? Do I have it wrong - could a 54 oz G powered rocket be launched without cert?



You know I like pictures... I was lucky to "assist" with this one. I did have some hands-on, but it was mostly "watch and learn".


p.s. - I'm not lazy and I look things up

Never bet against Sabrina! Sabrina is correct and I was wrong. As soon as a rocket has more than 1500 grams of mass it becomes Class 2 for FAA and requires high power certification under NFPA 1122 and 1127. I apologize for my error.

Steve Shannon said:

Unfortunately, the definition of class 1 and 2 rockets according to FAR 101 and the boundary between model rockets/high power as delineated by NFPA 1122 and NFPA 1127 do not align at the bottom end. Class 2 rockets require a COA (waiver). It’s possible to have a high power rocket that doesn’t require a waiver. It’s also possible to have a Class 1 rocket (no waiver required) that requires high power certification to buy and use the motor. Different authorities have imposed different rules.

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An example of a “high power rocket” that doesn’t require a waiver is a rocket that weighs less than or equal to 1500 grams, flying on an H motor with 125 grams of propellant or less or a G with greater than 80 N average thrust or a sparky. NFPA 1122 and 1127 deem those high power motors and any rocket propelled by one is a high power rocket. The motors used require certification to purchase with limited exceptions. But to the FAA that’s still Class 1 and requires no waiver.

Steve Shannon said:

I think you mean grams of weight for your motors, rather than grains.
Assuming each is 60 grams, that’s 120 grams. If the Minnie is already almost 1500 grams (say 1400) the total ends up at 1520 (1400 + 120 = 1520) so there must be a waiver.
But your two motors don’t add up to 320 Newton seconds of impulse and neither one exceeds 160 N-s, so you would not need to be certified.
I’m answering from memory, so maybe someone will catch me in a mistake.

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Here’s where I made my mistake, saying “you would not need to be certified.” As soon as the rocket has more than 1500 grams of mass it becomes a “high power rocket” under NFPA 1122 and 1127, which use the same definitions for model rockets and high power rockets. My last sentence turned out to be prophetic.

jqavins said:

According to ThrustCurve.org:

• The G80's impulse is 132.2 Ns, so two of them together come in at 264.4 Ns and would be OK with no cert. But a single motor at 264 Ns would not.
• The average thrust is actually 86.7 N, so it's over the limit. But I've heard before about it being considered mid power based on its labeled thrust. I don't know how they get away with that.
• The propellant mass is 63 g, so two of them together gives 126 g, which exceeds the limit.

Click to expand...

That’s an interesting detail - The first 2 generations of G80 motors (1st: silk screened phenolic, 2nd:molded w/o thrust ring) had much less propellant than the current version, and probably did fall within those limits. If we follow the NAR motor cert numbers, seems like 2 G80s would indeed require L1 (avg thrust) and also be considered class 2 (prop weight).