Dual Deployment Quandary

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Buckeye

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So you're not really doing dual deployment. You're using JLCR with electronic apogee charges instead of motor eject.
Huh? Any two events counts as dual deployment in my book. Using 4 electronics to accomplish that is, well, kinda nuts.
 

dhbarr

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If i use the wrong definitions or distinctions I'm really sorry.

Why don't you publish what is 1.0, 2.0 or whatever variations you feel are needed so we don't get confused and use the wrong ones in the future.
I got bit by the they-can't-see-me-waggling-my-eyebrows-and-smiling-impishly text problem :-D

JLCR's have two discrete events, that makes them DD in my books, same as prairie cutters or tinder descenders.

I have only heard of a few flights with three events, none with four or more.
 

MikeyDSlagle

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Airstart
Stage separation/booster chute deploy
Apogee/drogue for sustainer
Main for sustainer

4 events :cool:

Or are you talking four deployment events?

Adept Rocketry claims to have coined Dual Deployment and the term is a trademark of Adept Rocketry. Says so right there on their site. And they use dual event altimeters to achieve dual deployment. So to be true DD you would have to use a dual event altimeter. Right?

But wouldn't "dual" deploy mean two things deploying, ie two chutes?

So using a dual event altimeter with two chutes is DD 1.0, because it is the original.
Then came drogueless I would guess: DD 2.0, or is that DD 0.5 since you only have one chute? So using a JLCR would be DD 0.75? What about using the JLCR with a drogue?

In single break birds I use an altimeter for apogee then a JLCR for main. Sounds like dual deploy but I am only deploying one thing. Hmmm. I am gonna be like I am in Congress and just sit here on this fence.
 
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Bat-mite

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To me, the strictest sense of "dual deployment" means deploying two chutes at two different times. So JLCR and cable-cutters aren't really dual deployment. But, since they accomplish the same thing, i.e., delaying the opening of the main parachute, they could slide in under a looser definition.
 

Buckeye

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Man, the Rocketry Elite are out in force in this thread! So, drogueless doesn't count as DD, either?

Any 2 events that create 2 different descent rates (ballistic does not qualify!) is dual deploy.
 

Bat-mite

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Man, the Rocketry Elite are out in force in this thread! So, drogueless doesn't count as DD, either?

Any 2 events that create 2 different descent rates (ballistic does not qualify!) is dual deploy.
Not looking for a fight, and I don't personally care what anybody calls it. But in the strictest sense, "deployment" indicates that something was "deployed," which literally means "to be put into use. In a drogueless, nothing is being put into use.

Whoever it was above who distinguished between dual "deployment" and dual "event" was right, in the strictest sense. Any event is an occurrence of something, like an apogee separation, regardless of whether or not there is a drogue associated with it. But in a "deployment," something has to come out.

But like I said, I don't really care. It's like "further" and "farther." I know the difference, but I'm not going to pick on those who don't.
 

FredA

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Just to twist this thread a different direction......

"It's not preached as loudly as it should be. The apogee event is the most important part of dual deployment."

Agree -- then why do we allow L3's with "errant" apogee events to pass.
An L3 should be required to get it right.

Just sayin.......
 

Buckeye

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Shock cords are deployed.
 

Buckeye

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Just to twist this thread a different direction......

"It's not preached as loudly as it should be. The apogee event is the most important part of dual deployment."

Agree -- then why do we allow L3's with "errant" apogee events to pass.
An L3 should be required to get it right.

Just sayin.......
Ooh, yeah. :bangbang: This L3 cert topic has derailed many threads in the past! But, I agree with you. A successful mission is more important than bulletproof construction when it comes to certification.
 

Banzai88

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Hey, we've forgotten the ever popular "Duel Deploy", where the deployment events fight each other. Where does that rank on the scale? :tongue::wink:
 

dhbarr

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If someone had an airframe that bent at 45 °from the nose for the first event, thus radically increasing the drag; then split the aft into chopper blades 1,000 ft up....

This would be a no-deployment recovery?
 

Zeus-cat

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Hey, we've forgotten the ever popular "Duel Deploy", where the deployment events fight each other. Where does that rank on the scale? :tongue::wink:
I prefer the term Burr-Hamilton deploy.
 

Buckeye

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My favorite, Hillbilly Dual Deploy.
 

Steve Shannon

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Just to twist this thread a different direction......

"It's not preached as loudly as it should be. The apogee event is the most important part of dual deployment."

Agree -- then why do we allow L3's with "errant" apogee events to pass.
An L3 should be required to get it right.

Just sayin.......
I don't know, but that's a question better asked in the TAP forum on the Tripoli website.
 

blackjack2564

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Just to twist this thread a different direction......

"It's not preached as loudly as it should be. The apogee event is the most important part of dual deployment."

Agree -- then why do we allow L3's with "errant" apogee events to pass.
An L3 should be required to get it right.

Just sayin.......

On this we both agree.

Having said that, [I am a TAP] I must follow the rule of law....just like in the guberment.
We may not like/agree with it, but our job is enforcement, if it changes back, then we can also.:dark:
 
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FredA

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"On this we both agree.

Having said that, [I am a TAP] I must follow the rule of law....just like in the guberment.
We may not like/agree with it, but our job is enforcement, if it changes back, then we can also. "


That's why I bailed on TAP-ship. Wasn't putting my name on the dotted line for what I believe in my heart is a failure.
I'd post on the "TRA TAP FORUM" but that is a closed forum for TAP's only.
That's why I chose to hit on Steve's comment since he's the man..........
 

pondman

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Fred & Jim: I agree with both of you. If you look at the last sentence on the TRA L3 page: Any other legitimate reason the TAP member deems merits non-certification. I tell all the TRA L3 candidates that their rocket MUST follow the designed flight plan or they will fail. If they pop the main at apogee, they will drift outside of our waiver cylinder. Unless they have a VERY low flight. No issues so far......
 

FredA

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"I tell all the TRA L3 candidates that their rocket MUST follow the designed flight plan or they will fail."

I tried that under the umbrella of TAP discretion. Was told that was unfair and I need to stop immediately....so I did.

Let it go - don't want the "IBTL" trolls to be right.
 

cerving

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"I tell all the TRA L3 candidates that their rocket MUST follow the designed flight plan or they will fail."

I tried that under the umbrella of TAP discretion. Was told that was unfair and I need to stop immediately....so I did.

Let it go - don't want the "IBTL" trolls to be right.
Not trolling, but doesn't it seem reasonable that if you're going for your L3, which is supposed to be the pinnacle of achievement in hobby rocketry, that you should be able to model your flight accurately and have that flight execute your model with all events occurring nominally within a reasonable tolerance? That being said, I've never heard of a TAP asking to see the data from the flight computer before he'd sign off...
 

MikeyDSlagle

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Looks like the thread is derailed a bit anyway so...
I am nowhere near L3 but I would think on a L3 cert flight you should get it right. You say it pops a droque at apogee and it pops main, that should absolutely be a failure. If you say you will pop the main at apogee then fine. Altitude...well I fail to hit altitude on most of my sims, something is always off, I wouldn't want to have to hit a target altitude. Unless they check altimeters...but there are some dual deployment devices that do not record altitude.
Event wise, recovery wise, you should be able to follow a flight plan. But I am only a low L1.
 

Steve Shannon

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"On this we both agree.

Having said that, [I am a TAP] I must follow the rule of law....just like in the guberment.
We may not like/agree with it, but our job is enforcement, if it changes back, then we can also. "


That's why I bailed on TAP-ship. Wasn't putting my name on the dotted line for what I believe in my heart is a failure.
I'd post on the "TRA TAP FORUM" but that is a closed forum for TAP's only.
That's why I chose to hit on Steve's comment since he's the man..........
Fred,
I'd be happy to discuss it in email or on the members forum on the Tripoli website. I just don't want to hijack this thread. I'm bad at that as it is.
 

Lowpuller

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Ok, this has raised a question for me, just seeking opinions of those who have weighed in here already.

I am preparing to go for my L3, about a year from now, frankly waiting on a suitable kit to go on sale.

So you know I am building firm a kit, thoughts on this.

I also plan to use redundant altimeters. Let's say my fly appears to go perfectly from the ground but on inspection it is apparent one of my altimeters failed.................


Ok, my kit built rocket appears to fly perfectly, but on inspection one altimeter filed to work properly..........in your opinions, did I pass?

And please make suggestions for a kit.............
 

Steve Shannon

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Ok, this has raised a question for me, just seeking opinions of those who have weighed in here already.

I am preparing to go for my L3, about a year from now, frankly waiting on a suitable kit to go on sale.

So you know I am building firm a kit, thoughts on this.

I also plan to use redundant altimeters. Let's say my fly appears to go perfectly from the ground but on inspection it is apparent one of my altimeters failed.................


Ok, my kit built rocket appears to fly perfectly, but on inspection one altimeter filed to work properly..........in your opinions, did I pass?

And please make suggestions for a kit.............
I won't make a suggestion for a kit; there are many out there.

An important thing is to discuss with your TAPs what conditions would result in failure. When you're ready, ask your TAPs this question.
If I were your TAP and you asked me here is what I would say: The reason redundant electronics are required is in case one of them fails. The whole idea is so that people learn and perfect techniques that result in safe flights. So, yes, if one altimeter fails during flight but the other works correctly, I would sign off on your flight.
However, it's also a test of your knowledge and judgment. If I discovered that you wired your altimeter incorrectly, or heard one beep, got excited and forgot to turn on the second, I would really have to think about it.



Steve Shannon
 

snrkl

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But like I said, I don't really care. It's like "further" and "farther." I know the difference, but I'm not going to pick on those who don't.

Today I learned the difference between "further" and "farther"...

;^)
 

blackjack2564

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Ok, my kit built rocket appears to fly perfectly, but on inspection one altimeter filed to work properly..........in your opinions, did I pass?

And please make suggestions for a kit.............

Yes you pass if not YOUR fault......as mentioned, reason for dual avionics.

L-3 your rocket should "fit the field' you are flying on.
I think you fly with me at Camden?? If so a 4in and most 5's will bust the waiver 10,000.

And you know, unless absolute perfect conditions prevail, you don't want to go near that.

6 inch and above would be entry point , unless you plan to attempt somewhere else.
If your gonna fly where there is a higher waiver & GOOD recovery area 15,000 or more, now you open door to 4 inch kits.
6in on a small M will hit 5-8000 depending on weight & drag. [3-6fins?]
What say you?
Then we can recommend some things.
 

pondman

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Ok, this has raised a question for me, just seeking opinions of those who have weighed in here already.

I am preparing to go for my L3, about a year from now, frankly waiting on a suitable kit to go on sale.

So you know I am building firm a kit, thoughts on this.

I also plan to use redundant altimeters. Let's say my fly appears to go perfectly from the ground but on inspection it is apparent one of my altimeters failed.................


Ok, my kit built rocket appears to fly perfectly, but on inspection one altimeter filed to work properly..........in your opinions, did I pass?

And please make suggestions for a kit.............
Yes, I would pass you. Crazy Jim' suggestions based on field size are spot on too.
 

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