Motor expulsion

[tdn]

Since I was a kid, one acceptable form of recovery is featherweight or tumbleweight, in which the motor is ejected from the rocket by force of its own ejection charge. In fact, as little as 4 years ago I flew a rocket of this type. But now I've read (from multiple sources) that NAR doesn't allow this method. Is that correct, and if so, is this a recent development?

 

[wwattles]

I can't speak to the "legality" of the practice, but I know that some models are designed to eject their motors, such as the Squirrel Works "Red Baron" which is a boost glider, and needs to have the engine out or else it becomes a boost lawn dart.

Others can tumble recover even without kicking the motor.

Some localities also prohibit ejection of the motor due to various regulations/restrictions (fire, littering, environmental damage, etc). Once you've determined your range of possibilities with your governing body, you would be wise to check with your local organization about their site usage rules as well.

WW

 

[Zack Lau]

I don't see it in the NAR safety code.
https://www.nar.org/NARmrsc.html

However, it is a reason for disqualification if you are flying
in a NAR contest. It isn't hard to see why--my 1/2A PD model
would stay up a lot longer if I could kick a 4g engine casing,
cutting the weight in half.

PD is NAR shorthand for Parachute Duration

 

[sandman]

I don't think it's "illegal", just fround upon.

If you're flying in a farm field it's OK. The casing for a BP motor is completely biodegradable.

For competition...no...ya can't do it. For sport flying go right ahead.

 

[DynaSoar]

Originally posted by tdn
Since I was a kid, one acceptable form of recovery is featherweight or tumbleweight, in which the motor is ejected from the rocket by force of its own ejection charge. In fact, as little as 4 years ago I flew a rocket of this type. But now I've read (from multiple sources) that NAR doesn't allow this method. Is that correct, and if so, is this a recent development?

It's not in the code.

At least one Quest model (HL-20) currently uses this. They put a small streamer and piece of kevlar thread for you to tape to the motor so there's at least some additional safety factor. The old Estes Birdie required it; I assume the clone does also (Al?).

Could you please point me at the sources that say it's not allowed? I try to track such things down and eliminate the misinformation.

 

[rstaff3]

All I see on this is that you need a recovery system so the rocket 'returns safely and undamaged'. You have to read 'featherweight', 'tumble', 'aerobrake' into this statement, assuming you follow its inetent if not exact wording. Is a falling engine safe?

I also no longer see anything about launching biological payloads? My version is dated 2/2001.

 

[jflis]

I brought this up with NAR once a while back.

The code does not bring this up. The wording that I got from the NAR is that it is against the competition rules, specifically (eg: no feather weight models would qualify) and it was the opinion of the person I was speaking to that it was also against the sport flying rules.

Opinions aside, it does *not* say that in the code. Per the NAR Model Rocket Safety code, it is legal.

The only thing that comes close is the rule on recovery (rule #10):
Recovery System:]/B] I will use a recovery system such as a streamer or parachute in my rocket so that it returns safely and undamaged and can be flown again, and I will use only flame-resistant or fireproof recovery system wadding in my rocket.

I've had people tell me that this means that I must have a streamer on the casing. Not true. The rule above is talking about the model, *nothing* else. Additionally, it states "such as", it doesn't specify that it "must be". Good thing too, as glider models would be against the rules... The proof that the above rule is about the model and NOT the motor comes from the statement "...so that it returns safely and undamaged and can be flown again." By their very definition, SU motors can not be "flown again".

If such a rule were to exist then models such as the Sprite, Birdie, Spaceman, Nightwing, Sputnik, etc, etc, etc would never exist. Now, I would propose that their be *limits* on acceptability... I certainly don't want to see an M motor casing droping out of the sky over a crowd... ...but a a13mm or 18mm SU cardboard casing? sure, I don't see it as a risk. Certainly far less risk than hitting that gopher hole while on a full run after yer rocket

 

[rstaff3]

Hmm, it appears even the ancient NAR code requires a a bit of parsing and IMHO could be clearer. No wonder we're having troubles with things like the TRA cert codes, the Orange Book, etc.

 

[sandman]

I launched my Astron Space Plane twice at the NARAM 45 sport range and the RSO that checked it in didn't say a word about it.

The fact that the RSO at the table checking it in was Carl M. from SEMROC may have had something to do with it!

Three great flights too!

P.S. OT...So far Naram 45 was my favorite NARAM...except for the swamp...seemed like mostly Forum members were flying!

 

[DynaSoar]

Originally posted by rstaff3
Hmm, it appears even the ancient NAR code requires a a bit of parsing and IMHO could be clearer. No wonder we're having troubles with things like the TRA cert codes, the Orange Book, etc.

We've got rocketreers writing rules. Technically minded people trying to write comprehensive rule systems.

Could be worse. We could have adminimonsterswriting enormous rule systems with very little knowledge of the subject matter.

At least the former are working FOR us and are willing to fix things to our benefit.

 

[rstaff3]

Originally posted by DynaSoar
We've got rocketreers writing rules. Technically minded people trying to write comprehensive rule systems.

Could be worse. We could have adminimonsterswriting enormous rule systems with very little knowledge of the subject matter.

At least the former are working FOR us and are willing to fix things to our benefit.

Although I think the NAR rules coule be improved, but it is better than having a 50 page book...hmmm lets see what it says about popping motors...that would be in rule 56.3, subsection a, clause i...unless it's cloudy....

Adminimonsters...LOL

 

[tdn]

Originally posted by DynaSoar
Could you please point me at the sources that say it's not allowed? I try to track such things down and eliminate the misinformation. [/B]

Naturally, I can't find a cite now that someone's asking for one!

I remember reading it in two places. One was on this board, where somebody quoted part of what I thought was the NAR safety code, and bolded a bit that said something like "The rocket motor must remain affixed to the rocket during the flight." Maybe it was a competition rule that I was reading. I'd search for it, but I have no idea what forum it was even in.

The other place was in Harry Stine's book, IIRC in the chapter on gliders. I've re-read through the chapter, but couldn't find the passage. Dang credibility pixies must have gone and erased it over night. I hate when that happens!

 

[r1dermon]

i dont mind it, as long as people are using A motors. lol. last CMASS launch a D casing came falling out of the air, that would've left a little bruise. nothing severe, but still.

 

[rstaff3]

I was whacked by an E15 casing from my own rocket no less. It hit me on my arm and left a little round burn bark. It would have hurt more if it conked me on the noggin.

 

[Mad Rocketeer]

The X-24 Bug (which the Quest HL-20 resembles) ejected its motor too. I remember at the time trying to watch to see where the motors went. I rarely found one. You could hear it spit out when the ejection charge went off. I liked the rocket, but I never was in love with free-falling motors that litter at the least and could potentially start a grass fire or the like. Out in the middle of a plowed field or a rocky desert, with the permission of the owner, it would matter less. No huge deal, I guess, but it probably should be addressed by NAR in some future revision, just to cover the bigger heavier stuff.

Now if the adminimonsters were to get involved, we'd have to consider what constitutes rocket and what does not in the following cases and more.
* Reloadable Casings
* Small adapter stuff like centering rings.
* Tape used for friction fitting or rear thrust rings.

I kind of like the idea of taping a streamer onto the casings if possible. Nice touch. At least makes it more visible for clean-up.

Even if they were light and soft, price would keep folks from ejecting reloadable casings on purpose.

 

[Hospital_Rocket]

The Birdie will kick a motor with an ejection charge, If I use auch a motor I foiund a way to tether it. Although, to be honest it recovers nicer with a plugged motoer.

What would be real cool ids if there were a documented and approved method to plug a motor and remain within rules boundaries.

Think I'm gonna change my moniker to Boid-Man!

 

[Bazookadale]

Originally posted by rstaff3
I was whacked by an E15 casing from my own rocket no less. It hit me on my arm and left a little round burn bark. It would have hurt more if it conked me on the noggin.

This is the standard most contest RSO's use - would I want that hitting me on the head? If the answer is no it will be DQed as unsafe. And they will be much pickier on a contest range - too many pink book lawers just looking for ways to DQ someone else

Dale Greene

 

[Bazookadale]

Originally posted by rstaff3

I also no longer see anything about launching biological payloads? My version is dated 2/2001.

That was removed from the safety code a few years back because it had nothing to do with safety (except the animal's) but it is still against NAR policy - we don't need PETA to join forces with the ATF

Dale Greene

www.spaar.org

 

[GuyNoir]

Originally posted by tdn
Since I was a kid, one acceptable form of recovery is featherweight or tumbleweight, in which the motor is ejected from the rocket by force of its own ejection charge. In fact, as little as 4 years ago I flew a rocket of this type. But now I've read (from multiple sources) that NAR doesn't allow this method. Is that correct, and if so, is this a recent development?

As others outlined, it's not allowed for NAR competition. There's no other prohibition I'm aware of for ejecting engines.

Hope this helps.

 

[rstaff3]

Originally posted by bazookadale
That was removed from the safety code a few years back because it had nothing to do with safety (except the animal's) but it is still against NAR policy - we don't need PETA to join forces with the ATF

Dale Greene

www.spaar.org

So anyone know why it would be removed? IMO if its in the policy it should be in the safety code. Safety or not. So where are the rules that we must follow at sport launches that are not in the code?

 

[sandman]

So, let me see if i got this right.

As an example from my other thread on the Soyuz TM project,

https://www.rocketryforum.com/showthread.php?s=&threadid=13042&perpage=20&pagenumber=1

If I were to fly this model on the "sport range" at a NARAM with C6-7's in the boosters and just had them eject that would be OK?

And if I choose to fly it in the same configuration in "Scale Competition" that would be a DQ.

Is this correct?

 

[Zack Lau]

It is up to the Range Safety officer on the sport range whether the ejected C6 casings would be OK--I'd point it out before flying.

The ejected casings are a definite DQ for contest work. I disqualified my 1/2A cluster altitude flight because one of the 1/2A3-4T casings popped out during ejection. Similarly, I had to refly my Ariane V plastic model conversion because it spit a D12 casing. In both cases, the ejection charge was strong enough to spit the engine and properly deploy the recovery system.

 

[rstaff3]

Earlier I related the story about me getting whacked with a casing from my own rocket, which BTW was NOT planned If this had conked a 5 year old observer at the public park, the outcome could have been far different. Just food for thought. Maybe this is in the RSO training?