A streamer and A parachute duration - Rocket Designs

Discussion in 'Contests' started by uncle_vanya, Oct 23, 2008.

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  1. Oct 23, 2008 #1

    uncle_vanya

    uncle_vanya

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    I originally posted this on Rocketry Planet:

    Anyone have thoughts on plans for good "A" duration parachute and streamer rockets? These can be different or the same. If they are the same it would be easier - I could build two and have a spare if something goes wrong.

    I can't locate the plans for a rocket I built a while back I think it was called "Darkstar" and it was a pdf plan for a nice parachute/streamer duration model.
     
  2. Oct 23, 2008 #2

    powderburner

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    Have you looked at the competition plans posted on the NAR website?

    Fliskits also has a couple little rockets that look like they should be good for those events.

    Are you going to use a tower? A piston?
     
  3. Oct 23, 2008 #3

    Buzzard

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    A second powderburner's comments on going to the NAR site (www.nar.org). Under contest flying is a set of plans and the Darkstar is on the list.
    ASP (Aerospace Speciality Products) sells kits for both events. Their Hangtime kits feature Pratt vacuum form nose cones. IIRC, the SD kit uses a tissue streamer, but they also sell Duralar streamers. QCR also sells kits for these event. Must be why they are Qualified Competition Rockets. I believe they also offer a piston kit. I haven't visited their website in a while.

    Chas
     
  4. Oct 23, 2008 #4

    uncle_vanya

    uncle_vanya

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    To all - I had forgotten to check the NAR site because I forgot that they had a link to the DarkStar. I really liked that rocket the last time I built one and wanted the plans to do it again.

    EDIT - No link to DarkStar that I can find... Still looking.

    I think that it will be launched from a tower. Depends on who shows up. I don't have my own tower - but the guy who does is generous and allows us to use it.


    Any thoughts on the parachute?

    Any thoughts on flying a mini-egg loft style (ice cream cone-shaped) design with a huge chute?
     
  5. Oct 23, 2008 #5

    uncle_vanya

    uncle_vanya

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    I found the Darkstar plans. They were not easy the first time I used google I failed. But I found them linked on George Gassaway's site.

    The link pointed to Wooshrocktry.
     
  6. Oct 23, 2008 #6

    Micromeister

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    Brad:
    If you really want to be competitive with the BTC's, I'd strongly suggest using a 13mm paper tiger, or a taper Paper for Streamers and and 18MM for PD.
    I've packed as large as 8" x 80" 1/2mil mylar streamers in these 13mm straight tube Paper tiger models flying on A10 motors. It's easier to get a 6" x 60" so you be the judge.
    Personally the largest 1/4mil mylar chute i've gotten to blossom is 40" from an 18 to 24mm paperTaper (my design) model, but i've seen a 48" done by another club member.
    Generally 30" to 36" are good enough in local contests;)

    Most of the models below are hi rag content tracing vellum bodies with hollowed balsa, plastic or paper nosecones. just about all are flown with Sm styrofoam ejection plugs to protect and ensure ejection of these very thin mylar streamers and chutes.
    Hope this helpss

    039a-sm_25A-A 13mm Blkshaft SD_12-12-89.jpg

    440-sm_& 441 Taper Paper comp. Models_03-16-00.jpg

    441a-sm_TaperPaper 24-13mm PD&SD_03-16-00.jpg

    Ejection Plug Makers-a-sm_12-18-04.jpg
     
  7. Oct 23, 2008 #7

    HotRod Lincoln

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    Question for Micromiester and anyone else who uses Eject-plugs?

    Does the styro-plug just pop out and drtifts away or is it attached to the anchor line?
    Is it a one use item even if attached? I.e. how much melts?



    Just wondering.


    .
     
  8. Oct 23, 2008 #8

    uncle_vanya

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    ? BTC ?

    I'm not all that worried about super competitive. My goals are - respectable showing and reliable. I don't want to fiddle a lot with this between flights.
     
  9. Oct 23, 2008 #9

    Micromeister

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    Generally they just pop out and drift away, depending on the dia of the model I sometimes cut a slit along one side to center the shockline which sometimes keeps the plug with the model but they generally are used as wadding;) I also ALWAYS use 1/4 sheet of FPwadding between the forward end of the motor and the plug just to ensure a complete seal. Actually very little melts, even without the little bit of wadding. I often pick-up and reuse found plugs. just sand or cut off the tiny charred end and it's good to Re-go:)

    Brad:
    BTC= (Big Time Competitors)
    It takes no longer to create and prep these Paper Tiger or Taper Paper PD and SD models than to build any other type. As a matter of fact they are usually a lot quicker once you've built a couple. I have some of these paper bodied models that have flown as many as 10 times tho they are generally built for the bodies to servive 3-4 flights. Paper Tapers are very competitive with the ultra light, FAI type .5oz/yd3 single wrap fibreglass models.
    Shoot if you just want to make a showing ya might want to try what I did at last weekends Mars-31 Regional meet;
    For A PD I flew an OLD estes 18mm ECHO with a 12" 8 shroud 1/4mil mylar chute, single flight got almost 52 seconds and Got the model back!
    For B streamer I flew an 18mm Estes Courier with a micafilm 3"x 32" accordian fold streamer. If we're only looking for flight points to help the club, go easy on yourself, fly something interesting, a single flight in each event you plan on flying. This gives plenty of time to fly the events you really want and/or test and sport flights;)
     
  10. Oct 23, 2008 #10

    chanstevens

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    I'll be the contrarian here, knowing foam plugs are used a lot in international competition, but I personally avoid them like the plague. They tend to create a piston effect (duh...) which puts a Heck of a lot of stress on the shock cord/recovery system, which leads to a higher chance of separation or torn streamer. In my R & D report for NARAM last year, I studied over 7000 flight records from past NARAMS and found that streamer duration flights DQ'd about 28% of the time. Frankly, the key to winning isn't hitting exceptional times but in getting respectable flights every time. I go with a small amount of wadding, plenty of strong Kevlar, and I'm hitting about 90-95% reliability at this point.

    The other key is to avoid cramming the biggest chute/streamer you can into the tube. If it's tight, it shoots out like a canonball. For A impulse class, I'd recommend a BT-20 with a boattail down to 13mm motor tube, allowing A3 and plenty of volume for a 5x50 streamer or 15-18" chute (anything larger than 18" is not likely to stay deployed under a featherweight model). The Fliskits Cougar 660 is a pretty good starting point, and includes a sweet pop lug kit to give you tower-like performance without the headache of the tower. No other kit on the market addresses pop lugs...
     
  11. Oct 24, 2008 #11

    jflis

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    The FlisKits Cougar 660 is a competition streamer duration model that can be modified for parachute duration by lengthening the body tube to accommodate your desired parachute.

    It's a thought anyway :)

    jim
     
  12. Oct 24, 2008 #12

    chanstevens

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    Why would it need to be lengthened? Depending on which fin pattern is used, it's probably plenty stable even with lighter chute versus heavier streamer, and I've packed 18" chutes in about 3" length of BT-20 with no problems. :confused:
     
  13. Oct 24, 2008 #13

    jflis

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    Well, that came from conversations with others who have made a PD model out of the cougar and in each case they had problems packing their chute in the 8" tube and I suggested going with a 12" tube. Nothing to do with stability and I have never used this design in a PD event so... :)
     
  14. Oct 24, 2008 #14

    Micromeister

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    Chan:
    28%, Humm: That couldn't have anything to do with the fact many of those Naram flights were not by High precentage flyers to begin with could it? Folks using kit supplied FAR to short shocklines and/or attaching streamers with way to light a thread. Those folks out flying for flight points who attend Naram more for the social event the the competition?
    I've seen this effect even on the local and regional level as well. It sure has little or nothing to do with the use of ejection plugs, which do indeed AID in deployment of our recovery systems not detract from it. That's WHY all those international flyers use them so frequently. I have to take exception to your conclusion concerning the use of ejection plugs, particularly with regard to flying paper tigers.
    My S/D & P/D rates were over 95 percent also, once I started using longer kevlar shocklines and slightly heavier Shrould lines and streamer anchor
    attachments.

    Basic 18mm body models (BT-20's) easily handle 6" x60" or even 8" x 80" 1/2Mil. mylar or micafilm streamers if packed properly. I've seen several BTC's pack 10" x 100" in 19mm birds and max all three flights.

    While 15" to 18" chutes are nice super easy tri-folds of 18mm short bodies, halved 24" 1/4mil mylar has been the old standby for about as long as I can remember or been flying offering little or not packing pressure in the tube. Always providing Excellent performance and high 90% reliablilty in 18mm Featherweight model bodies. To me it's always seem MUCH more important to match the chute to the field conditions than the size stuffed in the tube....we do have to return as least one.
    I do agree pop lugs can be easier then towers, but have their own set of issues, misalignment, and initial drag. They are turely far easier to haul around then a tower:)
     
  15. Oct 24, 2008 #15

    chanstevens

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    There is no correlation between the serious/casual rating of the competitor and qualifiaction percentagein STREAMER duration in the NARAM data I studied (spanning about 7 years). In fact, looking at 2007's top-10 C division performers for the year, their career NARAM performance (for the 7-year study period) was actually slightly worse than the average competitor. The focus of my R & D was not specifically on the flight data, nor on other events, but if I had to toss out an educated guess (as I was asked to do in my oral presentation), I'd say that because the event is perceived to be so easy, we tend to think we need to push the envelope if we want to do better than flight points, and therefore shave too many corners trying to juice out every inch/second of performance.

    As for whether they fly kits or scratch, I have no data. Personal observation hanging with the "big timers" is that none use kits/all build scratch, so I can say for that roughly dozen or so C division flyers, kit shortcomings like wimpy shock cords are not an issue.

    Congrats on your 95% success rate, though I only see one flight record of you flying streamer in my NARAM data, for 100% success rate, so obviously the majority of your exerience is either local/regional or older NARAMS . Note, though, I'm talking specifically streamer in my comments, though the thread is streamer and chute. I do know chute DQ rate is much lower.

    Packing larger streamers/chutes in 18mm bodies is definitely not a problem, but depends hugely on the material involved and packing technique. I know, for example, of people that can pack 100" tracing paper streamers in a BT-20, but it is (in my opinion) overly tight/higher DQ risk, and those people that can do it are exceptional--most flyers that try to pack a 100" tracing paper streamer in a BT-20 will not pull it off or it will be ridiculously tight and DQ. Since we're talking A impulse, though, I'd question whether the larger streamer would actually result in better time, given the lower boost. The published studies are a bit thin, but would tend to contradict the benefits of a 10x100 streamer in A-SD.

    Switching to other materials like half mil Mylar or 1 mil Mylar makes it much easier to pack, but then we get into a whole 'nother debate about material weight versus streamer performance, and optimum streamer size versus weight by material, and even optimum folding techniques (accordion fold versus scorpion tail/claw technique).

    Please don't take this as a disrespectful comment/swipe, but I gotta tell you, I put a poopload of time/effort into researching streamer duration last year--read everything I could get my hands on, built/flew just about every possible commerical kit and published plan over the past 10+ years, and did a pretty thorough failure mode & effects analysis on it, and if you've got something that qualifies 95% of the time, deploying the type of big honkin' streamers you're describing, and presumably winning at the regional level, you really should consider putting it into some publication (R & D report, document posted on NAR site, etc.) to advance the topic rather than keep that stuff in this forum. TRF is a great place, but I'm telling you the hard data out there would suggest that your performance is truly cutting edge/fringe/exceptional, higher than the Trip Barber/Chad Ring/Bruce Marzelweski's of the world.
     
  16. Oct 25, 2008 #16

    Micromeister

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    Chan:
    That there is no distinction between the casual and intense competitors is exactly my point. I'm sure you've noticed the number of folks who come to open, Regional and Narams every year..just for the "experience". I don't really understand it myself but there are lots of them. They come,they fly for fun and go have another beer;) many of these don't bother with the details flying whatever is in there box that will work. If they have a seperation, jammed wadding or other malflunction it's really no biggy. but it sure squirrels the stats as seen in R&D reports.

    I doubt my stuff is any more cutting edge then those guys, the difference is I've just been doing it a very long time.
    Both the Taper Paper and Double taper paper plans & Write-up WERE sent to The Model Rocketeer mag then Sport Rocketry. Apparently they weren't viewed as worthy as they failed to be published? I assume the plans are still sitting in a box somewhere?
    Since a rather bad back and knee injury in 2000, I've all but stopped competiting and my Grumpy old man team teammate has retired also. I was thinking of attending next years Naram in PA but the real reason for the trip, Visiting my youngest daughter, has now move to California, so even the Lure of 1/8A H/D and Peanut Sport Scale may not be enough to warant making the painful trip. Today I'm still suffering the effects of what I did to my knees last weekend just recoverying models 200yds away, Bummer!. I'm beginning to believe my flying/recovery days may be numbered:(
    Actually my flight logs show over 95% deployment on 1/2mil mylar, or Red REAL micafilm streamer models going back as far 1988 after extending the lariet loop, Kevlar shocklines to 60". The most often flown size in 18mm models, generally B-D motor class was 6" x 60" tho many are an inch or so shorter as they get cut off due to wear.
    Generally 1/4A, 1/2A & A streamer/duration were flown in 13mm airframes with the vast majority logged with 4"x 40s" again real Micafilm. Man I wish we could still get that stuff. I've Known and flown with Trip much longer then Bruce, But have had many fond memoies of great times with them. Chad is chad, i've known him since he was a B divisioner we'll just leave it at that.
    I'm not disputing the research you've done, just saying there is apparently a vast amount of information that isn't well documented and hard for include. Your data apparently doesn't include the single wrap fibreglass FAI style 40mm body PD and SD airframes or the Paper Tiger or other tracing vellum bodied varients developed to combat the ultra light glass bodied models in NAR style competitions.
    I've flown these tracing paper varients for so long, I believe the Echo and Courier I used last weekend were the first standard body type models i've flown in a competiton since about 1990?
    All this to say don't poopoo varients you don't understand or haven't flown. ejection plugs...the subject I was talking about are an important part of the recovery system protection and deployment scheme for many a model is valid with a WORLD WIDE use record not to be ignored.
     
  17. Oct 25, 2008 #17
    Micro,

    All valid and interesting points but I think you may have misinterpreted one thing that Chan said. When he said
    You took that to mean there was no separation/distinction in the data.

    I suspect that what he meant (and how I read it) was that he had already separated the data to that level of detail and there was no significant statistical difference. If my reading is correct, then even the big time competitors suffer from the 25% failure rate. If *that's* true, then Chan's point is especially valid, your odds of winning go up significantly just by lowering your failure rate. In that case, then your 95% success rate would indeed make you stand out.

    Chan, did I get that right?
     
  18. Oct 25, 2008 #18

    Micromeister

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    I don't believe so John:
    Knowing how Naram stats and most contests for that matter, are compiled unless you personally know each and every competitor there is no way of telling which are "flying for fun" or really trying. An educated guess would be the very best one can do. Just because a well know competitor is entered in a given event does not mean he's going all out at that particular contest, let alone the causal flyer's attitude toward a given contest. Sometimes we just fly for fight points... I can tell you for a fact that's about all i've done for the last 8 years anyway;)

    I fully concur the BTC's are always pushing the envelope, thats how the "cutting edge" as Chan put it, is moved or expanded. Sure they suffer a lot of DQ's in the process, and your both correct, lowering the failure rate in any event, surely ups the odds of winning the day, particularly in multi-round events.

    The point I was making is that the 28% failure rate sighted, has far less to do with Ejection plugs and size of the recovery system then with attachment materials and methods of loading. One of the repeated occuring causes of streamer non deployment is stuffing too much wadding below it. It could be argued that a smaller streamer might have allowed the same amount of wadding to be ejected but the result is the same.....a DQ. Use of a constant size/diameter/thickness foam plug with a single 1/4sheet piece of wadding allows one to rule out wadding jam as the cause of a NO-deploy events. Then it's on to the #1 DQ culprit "seperations".

    Like Chan; I and others have been doing studies like this for decades. Not dismissing anything here just hopefully adding insight.
     
  19. Oct 25, 2008 #19

    gpoehlein

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    Out of curiousity, John, what do you use for wadding in your taper paper rockets? I've looked at the designs (and even tried one for 1/8A streamer and with George Gassaway's Two Minute Egg), but I'm curious what you do in a tapered body to protect the "laundry"?
     
  20. Oct 25, 2008 #20

    Micromeister

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    Like those below Greg?
    A .255" dia foam plug with the bit (1/4sheet or less on 1/8A stuff) of wadding between motor and plug in the motor tube and a single sheet of PFwadding "sleeved" around the Chute for streamer sort of like the old paper chute protectors from back in the stone age;)

    Without altering the motor/model by adding pyrodex or BP to the model; 22"dia, 1/4mil mylar, 8 shroud chutes are about the best l've been able to fully deploy in 1/8A PD. For my money, I'm happy to back that down to 18" for most flights unless it's a totally still air day.
    The Trick to packing is a single fold "Pinch" method used alot by the internats guys.
    This technique and protector method seems to works well with most of the conical Eggloafter bodies also:) tho the big Apogee Egg or old CMR cones takes two sheets crossed corners.
    Hope this helps.


    Ps: Greg: thats an awsome tag line you have!!! ROTFL!!!!

    216a4-sm_a-f Taper&Doubletaper PD's_8-30-04.jpg
     
  21. Oct 25, 2008 #21

    uncle_vanya

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    Details?
     
  22. Oct 25, 2008 #22

    Micromeister

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    You'll need to get one of them to show you, I'd never be able to explain it on paper or with a pictured how to. the sping created by the "pinch" has to be felt to be understood.
    Sorry somethings have to be seen or done in person.
     
  23. Oct 26, 2008 #23

    chanstevens

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    Yes, you got that right. While NARAM records don't differentiate between "fun" flyers and "serious" flyers, what I can say is that I would assume, for example, that the top 10 C division points earners in 2007 were very likely "seriously" competing, and that their performance over the 7-year period was not statistically different than other competitors. Any flyer who can consistently qualify in streamer duration 95% of the time is statistically exceptional, several standard deviations above the norm.

    Someone at one point had suggested that the high DQ% might be attributed to a number of casual competitors just playing around, or something to that effect, and I was basically saying that according to the flight data, the statistics contradict that--there is no significantly large group of flyers that stand out as better than average. Where there is statistical separation is that of the qualified flights, some folks tend to do considerably better than others, and that's where the casual/serious flyers are probably separated. They all, though, DQ surprisingly often.
     
  24. Oct 26, 2008 #24

    zog139

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    I'll chime in with a couple of observations on my models and kids models. I learned way back that the kevlar line was way to short on the original "Apogee" contest "tube" models. This has corrected the broken shock line seperations. I cant recall having a line break since then. ( hear sound of knocking on the wooden table ? )

    The issue I'm having now is the streamer tearing around the base where it is reinforced with trim monokote. I have also had some issues with the hole ( reinforced on both sides ) tearing and the kevlar basically "zipping" it's way through the mylar (1 mil thick) and the trim on both sides. Last week Matthew had a 5x50 deploy very easily from a BT-20 with no ejection plug and it just tore from one side to the other above the trim monokote resulting in a sep. This was a brand new never flown streamer?

    I flew a 6x60 also out of a BT-20 and it was fine and flew away :dork: Why ? Darn if I can figure it out.

    Jim
     
  25. Oct 27, 2008 #25

    Micromeister

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    Jim:
    How are you attaching the Kevlar leader to the streamers?
    I can't remember the last time i've torn off even a crepe streamer that way since using a needle to thread the leader up about 3" of the streamer then reinforcing with Mylar tape. Either along one side or directly up the middle. Can't recall if it was Dave O'brian or Dennis Kryway that showed me this method but i've used it ever since. They don't use the terminal tackle of coarse;)

    Streamer Fab-b1a-sm_.5mil mylar,Kevlar&needle_09-30-06.jpg

    Streamer Fab-b1c-sm_needle & line thur_09-30-06.jpg

    Streamer Fab-b1d_knot&pull back_09-30-06.jpg

    Streamer Fab-b2a-sm_overlay thread with Mylar tape_09-30-06.jpg

    Streamer Fab-b3b-sm_Attachment line finished_09-30-06.jpg
     
  26. Oct 27, 2008 #26

    zog43editor

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    Chan,
    Of those 28% what were the breakdowns of DQ reasons? I think that would be a better indicator of where the problems lie. At our recent regional the biggest issue with SD flights were seps caused by part of the streamer tearing off. That seems to be the case in my recollections from NARAMs going back a few years as well. It might be hard to quantify though, because a torn streamer is marked the same as a shockcord failure.

    kj
     
  27. Oct 27, 2008 #27

    zog43editor

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    The "pinch" comes partially from using large diameter chutes in large diameter models, and partially from material selection. The internats rules require a body diameter of 40mm for at least half of the model length (500mm). Instead of tightly folding and rolling the chutes to get into small tubes, you can get a relatively looser packed chute into the tube. I generally use a 30 or 36" diameter 1/4mil mylar chute with 12 lines. In a very light model it can take a bit for the chute to fall open and inflate withough something helping.

    The way I was taught the pinch was to start with the chute laying out and then fold over into a wedge, then pull the sroudlines up into the chute and wedge fold one ore time. Then take the point of the chute and fold down towards the shrouds, pinching in the fold fromt he sides. If you let go of the point of the chute, it should spring back out. It definitely helps to have a loosley packed chute instead of a tightly rolled one.

    The main thing is to get consistant deployments of the chute. THe folks that take the gold medals home from the internats are the ones who get their chutes to open every time and to open fully every time. Dead air times for these models are usually in the 4-5 minute range on an A motor.

    kj
     
  28. Oct 27, 2008 #28

    zog139

    zog139

    zog139

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  29. Oct 27, 2008 #29

    Micromeister

    Micromeister

    Micromeister

    Micro Craftman/ClusterNut TRF Lifetime Supporter TRF Supporter

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  30. Oct 27, 2008 #30

    gpoehlein

    gpoehlein

    gpoehlein

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    On a humorous side:

    I noticed that the title of this thread shows up as "A streamer and A parachute..." on the main page. Every time I see it I keep thinking it is the lead in to a joke:

    A streamer and a parachute walked into a bar... ;)

    OK - back to your regularly scheduled discussion! :p
     

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