Weight Question

[BigDuphis]

Question about a rocket weight...I have a rocket I built to use for my L1. Fully prepped it weighs in at 57oz w/ a G76. It sims safe ~600ft, 37mph at end of a 8ft rail. Would I be able to fly on the G (at a HP lauch w/ waiver) without a L1 cert on a G, or does it being over 3.3lb require me to go right to the H/cert flight?

 

[DavidMcCann]

G76 will do fine, it hits like a sledgehammer.

You need an FAA waiver in place. And to be certified (edit)

 

[DavidMcCann]

double post

 

[rharshberger]

Question about a rocket weight...I have a rocket I built to use for my L1. Fully prepped it weighs in at 57oz w/ a G76. It sims safe ~600ft, 37mph at end of a 8ft rail. Would I be able to fly on the G (at a HP lauch w/ waiver) without a L1 cert on a G, or does it being over 3.3lb require me to go right to the H/cert flight?

I have flown my 63oz Crayon rocket on G76-4 and it gets about 500', however, a 4 second delay is barely short enough and if you get a AT bonus delay the rocket may hit the gtmround before the chute can open ( its how my sons Crayon rocket died, chute opened at 20', recovery harness was 25' long....). Yes you can fly the rocket on a G at a waivered launch. At 37mph fly it on a windless or very calm day, better yet dont risk the rocket on a G, just make the cert attempt on a H, then go back and see if its ok on a G.

 

[UhClem]

Would I be able to fly on the G (at a HP lauch w/ waiver) without a L1 cert on a G, or does it being over 3.3lb require me to go right to the H/cert flight?

By definition (NFPA 1127 - 3.3.13.1) any rocket weighing more than 53 oz. is a high power rocket requiring user certification to fly.

 

[dhbarr]

Check to see if any of the hard-hitting disposables will get you in underweight?

 

[djs]

By definition (NFPA 1127 - 3.3.13.1) any rocket weighing more than 53 oz. is a high power rocket requiring user certification to fly.

Not exactly.. "user certification" is not really a law- it's internal regulations that NAR, Tripoli, etc came up with to make sure that flying HPR type motors at their launches are restricted and monitored. NFPA 1127 and FAR 101 is only related to when a waiver is required and other launch related activities (minimum safe distances, etc). Theoretically, you could get your own HPR motor (or make one), get an FAA waiver, and fly it on your own. Not that I condone doing this, but legally it's possible.

In this guy's case, he needs to fly somewhere with a waiver, due to the rocket's weight, but doesn't need to be an L1.

 

[Steve Shannon]

Not exactly.. "user certification" is not really a law- it's internal regulations that NAR, Tripoli, etc came up with to make sure that flying HPR type motors at their launches are restricted and monitored. NFPA 1127 and FAR 101 is only related to when a waiver is required and other launch related activities (minimum safe distances, etc). Theoretically, you could get your own HPR motor (or make one), get an FAA waiver, and fly it on your own. Not that I condone doing this, but legally it's possible.

In this guy's case, he needs to fly somewhere with a waiver, due to the rocket's weight, but doesn't need to be an L1.

Well, just to clarify, most states and many municipalities have incorporated NFPA 1127 by reference as part of their fire code or as part of their building codes. It’s extremely doubtful that anybody would ever be charged with such a violation of the requirement for certification unless it’s just something they tack on to other charges to make someone’s life miserable, but it is possible. I suspect many AHJs don’t even know about the requirements as they are incorporated by reference.
You’re exactly right about the Certificate of Authorization (waiver).

 

[djs]

Well, just to clarify, most states and many municipalities have incorporated NFPA 1127 by reference as part of their fire code or as part of their building codes. It’s extremely doubtful that anybody would ever be charged with such a violation of the requirement for certification unless it’s just something they tack on to other charges to make someone’s life miserable, but it is possible. I suspect many AHJs don’t even know about the requirements as they are incorporated by reference.
You’re exactly right about the Certificate of Authorization (waiver).

You have a point here- that NFPA recognizes certification, although in my reading of it, it doesn't really have sections like L1, L2, L3, other than "must be certified according to the certifying organization". So it is sort of a NFPA law, and sort of a Tripoli/NAR law

Either way, dude with the G76 rocket... go ahead and fly it, assuming you're willing to take a risk with the "bonus delay"...

 

[rharshberger]

FYI, a "bonus delay" is an AT delay (typically, but can be any manufacturer) that is longer than expected, and the reasons can be several, older delay (how long was the motor on the shelf/dealer), drilled but still left long (adjustable delays are kind of arbitrary), or maybe it just burned a bit longer (whatever reason). Delays are supposed to be within a certified spec and most are, however occasionally we get slightly longer or shorter ones, which is bad news on a low flying rocket.

 

[djs]

Just a note to the OP- if you're flying a G76G-4, do not drill the delay to get it down to 3 seconds or something like that. Bad things can happen when you get a delay that short.

 

[samb]

Hmmm... Simple question, simple answer. Yes, L1 is required to fly a rocket weighing more than 1500 grams (or 53 ounces or 3.3 pounds) at a NAR launch. I thought Tripoli followed the same rule but I'm not a member of that organization and maybe y'all changed something.

 

[Steve Shannon]

Hmmm... Simple question, simple answer. Yes, L1 is required to fly a rocket weighing more than 1500 grams (or 53 ounces or 3.3 pounds) at a NAR launch. I thought Tripoli followed the same rule but I'm not a member of that organization and maybe y'all changed something.

Nope, we didn’t change anything. Anything over 1500 grams/53 oz. is considered a high power rocket, regardless of what impulse motor is in it and requires high power certification and a waiver to fly. To do otherwise would be a violation of NFPA 1127 and NFPA 1122. Tripoli adopted NFPA 1127 as the foundation of its Safety Codes years ago.


Steve Shannon

 

[LithosphereRocketry]

I have a follow-up question...

Are there cases where you can fly a HPR motor without a waiver? Say a 3lb rocket on a Loki 38-240... 120 grams of propellant so no waiver needed according to FAR101, correct?

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[DavidMcCann]

I have a follow-up question...

Are there cases where you can fly a HPR motor without a waiver? Say a 3lb rocket on a Loki 38-240... 120 grams of propellant so no waiver needed according to FAR101, correct?

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We have launched under those conditions after closing the waiver. As long as you have the space I believe that works.

 

[LithosphereRocketry]

We have launched under those conditions after closing the waiver. As long as you have the space I believe that works.

Ok, good to know...

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[BigDuphis]

Seems to be some conflicting responses, maybe I should be a little more specific. The HPR launch close to me is MDRA, so maybe an RSO from that group can chime in as to weather this would fly there? I intend to go sometime after the new year, as it doesn't really make sense to pay dues now when they reset at the end of the year.

 

[samb]

Seems to be some conflicting responses, maybe I should be a little more specific. The HPR launch close to me is MDRA, so maybe an RSO from that group can chime in as to weather this would fly there? I intend to go sometime after the new year, as it doesn't really make sense to pay dues now when they reset at the end of the year.

Not sure why. NAR and Tripoli launch rules are pretty clear. If I'm not mistaken MDRA is an independent so yeah, getting a ruling from them would be in order. But you came to the 'Ol Forum so you get the grab-bag !

 

[samb]

I have a follow-up question...

Are there cases where you can fly a HPR motor without a waiver? Say a 3lb rocket on a Loki 38-240... 120 grams of propellant so no waiver needed according to FAR101, correct?

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Correct. Another easy one. The FAA rules for waivers are based on propellant weight and rocket weight. A few high power motors fall under the limit. The logistics of flying and recovering one of those might be a concern.

 

[0011001100]

Seems to be some conflicting responses, maybe I should be a little more specific. The HPR launch close to me is MDRA, so maybe an RSO from that group can chime in as to weather this would fly there? I intend to go sometime after the new year, as it doesn't really make sense to pay dues now when they reset at the end of the year.

*Not an RSO but I go there regularly*
MDRA is independently insured, HOWEVER, that does not mean we don't follow Tripoli/NAR codes. We still do and thus I am 99% sure you would need to be a L1.

 

[DavidMcCann]

well, could always trim 4oz off it and fly it.

You'd be shocked what...well... shock cord weighs. If you have TN, replacing it with paracord could get you under. using quciklinks anywhere? toss 'em and tie knots.

 

[BigDuphis]

Unfortunately it's pretty bone stock. No hardware other than the eye bolt mount. I think most of the extra weight is in epoxy for internal fillets (built it like a tank) and the paint. (Black metallic super batray w/ a real glossy smooth finish)

well, could always trim 4oz off it and fly it.

You'd be shocked what...well... shock cord weighs. If you have TN, replacing it with paracord could get you under. using quciklinks anywhere? toss 'em and tie knots.

 

[Sabrina]

Question about a rocket weight...I have a rocket I built to use for my L1. Fully prepped it weighs in at 57oz w/ a G76. It sims safe ~600ft, 37mph at end of a 8ft rail. Would I be able to fly on the G (at a HP lauch w/ waiver) without a L1 cert on a G, or does it being over 3.3lb require me to go right to the H/cert flight?

What a coincidence!?! :surprised:


The EXACT same thing happened to my mom a few years ago when she went for her L1.


She built a Wildman Darkstar :dark:, and intended to fly it on a G80 for it's first "shake-down" flight.
The sim showed a safe flight to about 750 feet. Then she was going to fly an H115 for her cert. -
She assembled the rocket with the G80 and it was over the class 1 weight limit.

If you're going to fly HP, it's really important to know and follow all the rules and regs. -If you don't know, ask and search the web. -This stuff (rules and regs) - easy to find and learn.


Realize you're putting yourself, your club, the land owner, the insurance carrier, the national organization, and all your fellow Rocketeers at risk if a bad accident happens :jaw:, and it turns out your flight was in violation of the rules.
Just think ahead a bit - someone gets hurt, or there is property damage - your flight will be in the spotlight. An insurance adjuster, or the national organization might want to do an investigation.


+-+-+- Now back to my Mom's cert story >>> Mom had to remove the AV-Bay and the payload section from the Darkstar to get it under 1500 grams ready-to-fly on the G80.
She had a great flight - the "short" Darkstar did look a bit odd, but it flew GREAT on the G80.

The very next day she put it together "all-up" with the H115 and had another perfect flight -earning her L1.
Crazy Jim photo-bombed her after the flight.


Moral of the story - Mom knows and follows the rules, for the safety and enjoyment of all... >>> Be Like MOM!!!

 

[BigDuphis]

Sounds like I'll just do the L1 flight then. Plan to christen it with a Loki H160LB (I like em noisy)

 

[Steve Shannon]

Sabrina,
I don’t know how you got so wise, but I really appreciate it!

 

[LithosphereRocketry]

Sounds like I'll just do the L1 flight then. Plan to christen it with a Loki H160LB (I like em noisy)

There's an H100 SF you know... If a G76 is a good shakedown that's a great L1.

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[BigDuphis]

I looked at the curve and simmed the h100 and it actually is coming off the rail a few mph slower than the g76. It looks like it takes a little bit of time for it to build up full pressure and doesn't have that big kick right off the pad.

There's an H100 SF you know... If a G76 is a good shakedown that's a great L1.

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