FINCANS ALLOWED FOR CERT FLIGHTS? ?

Are you allowed to use pre-made one piece fincans for L1, L2, and L3 flights?

Not for NAR L3, there doesn't seem to be a rule against it for L1/L2

https://www.nar.org/hpcert/NARhprintro.html

Same for Tripolii L3.

"Commercially available pre-fabricated fin cans, either as part of a kit or obtained separately, may not be used for level
3 certification flights. "

Worsaer said:

Same for Tripolii L3.

"Commercially available pre-fabricated fin cans, either as part of a kit or obtained separately, may not be used for level
3 certification flights. "

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Well, darn.

There goes my idea for certifying Level 3 with a Centuri/Enerjet fin can. :wink:

What's particularly dumb, in my opinion, is the fact that my N5800 rocket's "fin can" prevents me from flying it for a certification. This I do not understand, and every part of the design,machining, construction, and modeling was original-it's not like I bought the darn thing, it's an entirely original design, and I have the photos and video to show I made it myself. In my lowly, unimportant opinion, that is dumb.

(The ruling on my fincan comes from TRA HQ directly)

(I fully recognize that the spirit of the rule (L3 certifications should be low and slow, safe, proven designs) totally goes against the idea of certifying on an N5800 minimum diameter)

(I also fully recognize that the rocket I took to XPRS wasn't built entirely by me, therefore wouldn't be a good choice for certification, etc. etc.)

CCotner said:

What's particularly dumb, in my opinion, is the fact that my N5800 rocket's "fin can" prevents me from flying it for a certification. This I do not understand, and every part of the design,machining, construction, and modeling was original-it's not like I bought the darn thing, it's an entirely original design, and I have the photos and video to show I made it myself. That's just dumb.

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Having talked to you about your design in person, and watching you build it here on the internets, I'd sign it off.

Except that I made the nosecone for it.

Wait... if someone designs you a rocket, rolls you a body tube and cuts slots in it and makes you a nosecone and lays up plate and cuts fins and centering rings out of it, and then gives it to you to glue together, does it count as you having built it? That's no worse than just buying a kit. Whoever does the final assembly gets the credit?

Also, if I remember correctly, you have to drill and tap your own holes for Rouse-Tech fin cans, so you have to align it yourself, making it perhaps even harder to make than fins through pre-slotted body tubes.

CarVac said:

Except that I made the nosecone for it.

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Ah, team project. There's why you can't get a signature.

CarVac said:

Wait... if someone designs you a rocket, rolls you a body tube and cuts slots in it and makes you a nosecone and lays up plate and cuts fins and centering rings out of it, and then gives it to you to glue together, does it count as you having built it? That's no worse than just buying a kit. Whoever does the final assembly gets the credit?

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Kinda, pretty much, yeah. The standard for certification is that the flyer should be able to assemble a vehicle that is typical of the flights expected at that level. Whether that vehicle is assembled from component parts or hand rolled with fabric hand-spun from homemade glass fibers isn't the distinguishing factor; it's whether the flyer can competently integrate the required components according to a good design to make the flight a success. One of the skills being tested is fin alignment and attachment. The Rouse-Tech can falls into a grey area IMO due to its "some assembly required" nature; the original wording was put in the code to prevent someone from taking one of Curtis' 6" fin cans or a Dr Rocket Modular kit and flying it in an off-the-shelf configuration.

It's true that by the time we showed up in Gerlach it couldn't be used because it was a team project. However, the ruling against my fincan came back in June, before there was any 'team' involved in the planned actual assembly.

I would beleive its up to the TAP I don't think one needs to send a picture of rocket to HQ with L-3 paper work. The rules also say the L-3 must return with no damage or you don't pass. How many have seen a rocket with some damage and still get signed off?
gp

I don't think "no damage" is quite the standard. Damage that does not affect the airworthiness of the vehicle, so it can be flow 'immediately', is acceptable.

Kevin

crossfire said:

I would beleive its up to the TAP I don't think one needs to send a picture of rocket to HQ with L-3 paper work. The rules also say the L-3 must return with no damage or you don't pass. How many have seen a rocket with some damage and still get signed off?

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I'm not a TAP, but I am a Prefect, and my view on damage is this - if you can, without doing any repairs, turn around any fly it again on the same motor, then it's fine.

-Kevin

crossfire said:

I would beleive its up to the TAP I don't think one needs to send a picture of rocket to HQ with L-3 paper work. The rules also say the L-3 must return with no damage or you don't pass. How many have seen a rocket with some damage and still get signed off?
gp

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My L3 flight had damage; a crack in the laminate in the upper end of the booster. After video review by the "replay official" (yeah, kinda like the NFL), it was determined the the likely cause was drag from the parachute after landing. As it turned out the crack was only surface damage and the rocket could have flown again anyway, but some anxious moments as my TAP was making the determination.

CarVac said:

Except that I made the nosecone for it.

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NAR rules say this:

"Certification rockets may be built from commercially available kits and may contain
components built to the specifications of the certifying flyer but fabricated by others."

Also, if you make your own fincan, it's not "prefabricated" IMHO and would be acceptable to NAR.

So it actually wouldn't be allowed for me to randomly design a rocket and scratchbuild all of the parts for someone else's cert given that

1. they didn't design it or
2. I didn't start offering it to everyone as a commercially available kit.

At least for NAR.

CarVac said:

So it actually wouldn't be allowed for me to randomly design a rocket and scratchbuild all of the parts for someone else's cert...

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I'm not sure what your point is. https://www.nar.org/pdf/L3certreq.pdf seems pretty clear to me. The rocket has to be "substantially built" by the certifying flyer, which basically means they have to assemble the parts per the specifics called out. I think those parts could be fabricated by someone else, commercial kit or not. But if you use a fincan, that part has to be made by the flyer, it appears.

What I meant was: If I designed and fabricated the parts, then the parts are not made as specified by the flyer. In that case, it needs to be a commercial kit, according to the rules: (quoted from your earlier post)

"Certification rockets may be built from commercially available kits and may contain
components built to the specifications of the certifying flyer but fabricated by others."

It's quite a literal interpretation, but in the worst case you might get called out for skirting the rules. Maybe.

The interpretation that matters comes from your certifying authority. Contact them early and often before and during the build process and you should have no difficulties or surprises when flight time comes.

I know it can be frustrating to have a fuzzy rule set like this, but it works really well, since each project and flyer is a special case.

daveyfire said:

The interpretation that matters comes from your certifying authority. Contact them early and often before and during the build process and you should have no difficulties or surprises when flight time comes.

I know it can be frustrating to have a fuzzy rule set like this, but it works really well, since each project and flyer is a special case.

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Right there, about the best summary I've ever seen of why the rules are the way they are, and how best to avoid surprises.

-Kevin

daveyfire said:

The interpretation that matters comes from your certifying authority. Contact them early and often before and during the build process and you should have no difficulties or surprises when flight time comes.

I know it can be frustrating to have a fuzzy rule set like this, but it works really well, since each project and flyer is a special case.

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"works well" is dependant on who you are, and what your trying to do. The defacto "works well" is mainly in the hands of the associative side of the certificaions.

I dont think it should be "frustrating" to get through the rules. On either side. while judgement calls are essential, they should be relegated to areas in the fringe not areas that otherwise are acceptable.

Such as, made your self fin cans... You said yourself you would accept that submission. But frustrating is that it was denied and I am sure reviewied and denied again.(probably for associative motives to uphold a final Tap member authority.) This is not "fuzzy" rules, its just inconsistancy, and that's why its frustrative.

That might sound a little abrasive and blind sided to your statement.. Please dont take it that way, just trying to explain the other side.
Since I think certificaitons are not to "test" a skillset of a persons level. I know that sounds counter intuitive... but a certification is only supposed to be "acknolegement and acceptance of observed capacity."
you either a L3 capable flyer or your not... one "project" controlled by "people who know better" is not an observation of existing skillset.


clay

CarVac said:

What I meant was: If I designed and fabricated the parts, then the parts are not made as specified by the flyer. In that case, it needs to be a commercial kit, according to the rules: (quoted from your earlier post)

"Certification rockets may be built from commercially available kits and may contain
components built to the specifications of the certifying flyer but fabricated by others."

It's quite a literal interpretation, but in the worst case you might get called out for skirting the rules. Maybe.

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I think you are having trouble with the word "may".

I just think it is poorly worded.

Ok and thanks for the info.

Still not quite sure if I built an aluminum fincan or fin assembly myself would that be allowable per the rules.

MGL said:

Still not quite sure if I built an aluminum fincan or fin assembly myself would that be allowable per the rules.

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It wasn't for me but ask your TAP, it seems to be inconsistent.