NAR/TRA Joint Active Recovery Definition

I was thinking more along the lines of a 6 inch diameter, 5 foot long

3FNC all carbon fiber rocket using a small H motor. The amount of drag on the rocket compared to it's weight would be about the same as coming in on a smaller parachute (I think, I would have to sim, build, test this all myself first) I seem to recall a similar rocket by PML that was launched on a G motor. It was so light, it could be held up with 2 fingers. Its first flight was on an H-180 and the booster came in without a parachute (not by design) with no damage to the rocket.

formatting link
This is not the method I choose when I got my level 1 (I-435 with dual deploy on a 7 pound AMRAAM) or my level 2, but it doesn't mean that a good builder (read strong but light) couldn't do it.

This seems like regulation for the sake of regulation to me. If a builder can explain WHY a rocket with no active recovery is still a safe recovery, then that would mean to me that he understands the physics of flight and would be a safe flyer. If they can't explain to me why its safe, then more than likely, they don't know why its safe and in that case, I would agree that they shouldn't be flying a rocket without active recovery (cert or no cert). This feels more to the spirit of the certification process to me. Almost anyone can but a LOC or PML kit, slap on some epoxy and an H motor and cert level 1.

This may not ban any type of rocket, (spool, saucer, oddroc, what-have-you) but it does ban a type of rocket for certification, one that uses passive recovery.

I guess it really doesn't matter at this point. The time for discussion on this has already passed. The rule is in place and to change the rule would take more than just my voice.

-Aaron

AZ Woody wrote:

Reply to
Aaron
Loading thread data ...

It could be worse. Long time ago you had to certify for each Motor level (i.e. H,I, etc). CAR has 4 certification levels.

At the L2 level you are expected to know and understand more about theory, > It just seem ridiculous to place so much emphasis on different power

Reply to
Alex Mericas

Kurt,

Do you have pictures of your rocket powered ships? Are they like hydroplanes or what?

Phil

Reply to
Phil Stein

The fact that we point ours pretty much straight up helps a lot.

Phil

Reply to
Phil Stein

From:

formatting link
"High power certification is intended to provide a measure of the modeler's competence to avoid gross violations of good modeling practice and safe model operation. The program is not foolproof. A single demonstration of a modeler's skills does not guarantee consistent safe performance. The certification program does not replace competent range personnel (note that high power range safety officers will require high power certification per NFPA 1127) to provide assurance of safe models and operating practices."

Apparently, "safe" is a primary operative word in the intended purpose of HPR certification.

Insofar as recovery is concerned, there are few, if any, safer recovery methods than those which are designed into the "physical configuration" of the airframe itself and require nothing to occur in order for recovery to be safe and effective.

I believe NFPA 1127 requires an HPR recovery system which allows recovery "without presenting a hazard"; a non-quantified, subjective criteria.

I'm not trying to start a flamewar or beat a dead horse here. In fact, I was worried a recovery incident had prompted the orgs to tighten their definitions and was just trying to understand what had happened.

If "safe modeling practices" and "safe model operation" are the intended purpose of cert flights, there is no reason to single out any particular recovery system. If they can be flown, the flyer should know how to safely build and fly them, be they saucers, helicopters, or electronic dual deployment birds.

The active recovery definition officially inserts an implicit skills test (physical configuration change)into cert flights and implicitly leaves out another, aerobraking. Its interesting to me that the fundamentals of any recovery system are inherent in the design of the inactive recovery model itself; drag and stability. I remember flying the tumble recovery models (Sprite?) as a kid and pondering over the description of CG changes and instability; good lessons for any type flying. When I first saw spools and cones, and similar oddrocs, I was similarly drawn to find out how and why they flew. I wonder if designing an inactive recovery oddroc requires more or less fundamental rocketry understanding than does designing a 3FNC. In any case, IMHO, the active recovery definition/restriction is unneeded and serves no function related to the stated intended purpose of HPR certification.

Thanks to all who responded to my original post.

Reply to
Gary

Perhaps. And if someone hadn't pushed the BoT for clarification on the issue we probably would have been left with "don't ask, don't tell".

Sometimes its better to not ask for clarification on an issue.

Reply to
Alex Mericas

Correction: "These types of rockets." :-)

Kurt

Reply to
Kurt

I was ready to make one to try out in a friend's pool. ;-) In leiu of that entertainment, maybe I'll try the Baby Ruth trick.

Phil

Reply to
Phil Stein

And you've never heard of one that failed to go straight up?

Mario

Reply to
Mario

But why should they need active recovery, provided that the descent rate is limited?

Yeah, I heard about that. I'm not totally in favour of those saucers that are little more than a skirt around the aft closure of a motor either.

I just think it's a pity that a potential class of vehicles that do not possess "active recovery" and yet have a safe terminal velocity has been ruled out of use for certification. What ought to matter in a cert flight is the demonstration of a safe flight, from launch to recovery.

What's next - you can't certify on a single use motor, because it's too easy? Maybe ban those Proxx motors for cert flight - they're a bit easy to assemble (except that I've seen people get it wrong) too.

Perhaps cert-flights should be like driving tests. You pass your test in an automatic, you can drive an automatic, you pass your test with a stick shift and you can drive those too. Want to drive a motorbike or truck? Different test. Is it actually like that in the US? It is over here in the UK.

Maybe the "grand certification flight" should be done away with completely - perhaps everything a flier does for the first time should be certified. You could have a membership card with little ticks for

- each class of motor flown

- single use flight

- reload assembly

- hybrid motor

- streamer deployment

- parachute deployment

- CPR

- etc...

Just kidding.

Reply to
Darren J Longhorn

That is extremely rare but I'm sure you know that.

Phil

Reply to
Phil Stein

What the various levels are really testing is your ability to design and build a rocket capable of withstanding the increased forces of a larger more powerful motor. Although I was opposed to the multi-level cert system, I must admit that it _appears_ to have reduced the rate of cert flight failures. I say this based only on my personal observations over the years, so take it with a grain of salt.

I don't think the current three-level system is particularly burdensome or onerous. We can keep it that way as long we can resist the "there oughta be law" knee-jerk reactions to every perceived problem or pet peeve.

2
Reply to
raydunakin

This whole topic has got me thinking about old times...

Speaking of oddrocks, what ever happened with Chris Taylor's Grrrrrrrrrrr. As I remember it was quite a failure the first time he tried for L1, but that was a few years back.

I also recall that it was to be a glider, with no active recovery. And was tested by strapping it to his jeep, and he drove "as fast as he could".

I remember that spectators hoped that there was no wind during the launch, but it had something to due with a Kilt....

One of the things (and maybe the only one) that Kaplow and I have agreed on in the many years of RMR, is that the K.I.S.S principle should be used for all cert flights.

K.I.S.S - Keep It Simple, Stupid.

Do what you need, and don't complicate it with oddrocks, or anything the folks doing the cert might not understand. Trying for a cert where the prefect, or NAR cert team, has no clue on validating your bird (a saucer , spool, or jeep tested glider), might not be the best way to get a cert.

Reply to
AZ Woody

AZ Woody wrote: > ... [Chris Taylor's Grrr] was to be a glider, with no active recovery.

It was recovered via R/C control. Chris' possibly misplaced ambition notwithstanding, I sure hope this "NAR/TRA joint active recovery definition" includes R/C control of a glider (it seems to, though "glider" is not mentioned explicitly).

Reply to
Steve Humphrey

I believe that R/C is specifically listed as being an acceptable "active recovery" method.

-Kevin

Reply to
Kevin Trojanowski

But did he actually get it to work, and he got a cert? If so, when!

And how did the kilt do during the flight?

For his first cert attempt atleast, this was clearly a backing for the new rule. Based on what he was saying about his bird, and how he tested it (The jeep part was no joke), I'm still dumbfounded that any RSO allowed it!

Grrrrrrrrrr to me, only backs up why the new rule was needed...

Reply to
AZ Woody

And if I might add... r/c = THE most prime example of "active recovery" :)

Ted Novak TRA#5512 IEAS#75

Reply to
the notorious t-e-d

IIRC, the RSO put it on a pad far away from everything else and called it a "heads up" flight, requiring everyone to stand up and pay attention. I think this was a good call on the RSO's part.

Reply to
Alex Mericas

The status of the R/C control of gliders used in HPR certification flights was specifically discussed at the NAR Town Hall meeting Monday night. Mark's answer was that it met the criterion of active recovery.

Data mining of launch reports and flight cards indicated that ~75% of all flight failures involved the recovery system of the airframe. Beyond this is the belief that nearly all HPR fliers will use rockets sometime in their flight activities/history that will employ active recovery. It was also judged to be highly unlikely that a flier using a HPR non-active recovery system for their certification flight, would only fly airframes of that type as a HPR participant in the future.

The active recovery requirement only applies to certification flights, so what a flier chooses to employ as a recovery system is their choice as long as it meets the safety code requirements.

Personally, foam bowl saucers are my favorite small field rocketry demonstration tool for schools. They are inexpensive, can be quickly assembled by the students, fault tolerant, detailed/customized using white board markers, and can be flown on a wide range of motors.

John

AZ Woody wrote:

Reply to
Johnly

Agreed. A cert flight is a place to demonstrate what you've learned on smaller models, not the time to do new and different stuff.

Reply to
Bob Kaplow

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.