Cobalt Wing Loading

[Geoff 0]

Does anybody else here agree with Dan's claim that Cobalts should be loaded higher than other canopies in order to fly at the same speed?
Most people who've jumped Cobalts and Crossfires seem to think they fly very similarly - Is that for the same wing loading, though - will a Cobalt 120 fly slower than a Crossfire 120?
I know I should demo the canopies but they're difficult to get hold of here in the UK, and the range of available sizes is limited.
Thanks
Geoff

[SkymonkeyONE 3]

I agree with Dan 100%, and not because he sponsors me. The Cobalt flies much bigger than same-sized parachutes due to it's very-efficient airfoil and the way the jumper is suspended farther back under the canopy. The analogy that the Crossfire flies like the stock Cobalt is basically true, however in order to get that same "feeling" you must be jumping different sized chutes. That is to say a Crossfire 85 (or whatever the closest size is to that) flies very similar to a Cobalt 75. You wouldn't catch me dead under a Crossfire 65 (if they made one), but I put about 50 jumps on a Cobalt 65 with no problems whatsoever. Is a Cobalt a fully elliptical main? Yes. Is it still considered a high performance main even when mildly loaded? I would say so, BUT the parachute is generally VERY docile and must be worked pretty hard at lighter wingloads to get the speed you would normally get with a similarly sized main of different design. It is for that reason that the airfoil is marketed at both the intermediate and advanced/pro jumpers. It is a COMPLETELY different animal when loaded at 1.5 compared to 2.3. I have loaded a Competition Cobalt 65 to 2.8 and landed it straight in. Try that with a Crossfire/ Stilleto/ Vengeance.
Did I mention that I would be competing under a x-braced tricell Atair canopy next season?
Chuck
My webpage HERE

[jfields 0]

Chuck,
You said:

Quote

It is a COMPLETELY different animal when loaded at 1.5 compared to 2.3. I have loaded a Competition Cobalt 65 to 2.8 and landed it straight in. Try that with a Crossfire/ Stilleto/ Vengeance.

I currently fly a Sabre at about 1.15:1, and have no plans to try anything highly loaded or eliptical, but I'd still like to understand what is going on. What are the issues that make flying highly loaded elipticals straight in such a problem? What flight characteristics do they have under those conditions?
Thanks!
Justin
My Homepage

[landmissle 2]

Hi Geoff,
I think this will be one of those relative/subjective topics. I'll give you my impressions that may or may not be (kinda' covers all angles...) applicable to anyone else.
I'd been flying my first canopy a Safire 169 for about 60 jumps when I first demoed a Cobalt 170. I'd talked to Dan Preston (CobaltDan) before ordering the demo and he suggested that I request the Cobalt 150 in order to get a more apples-to-apples comparison between the Cobalt and my Safire. I wasn't comfortable with the idea and ordered the 170.
My immediate impresson under the 170 was that in turned and responded slightly slower than my Safire 169. Could this have been in my head? Possibly, but realize that I thought Dan and Atair's claims where hype or marketing rhetoric so I was skeptical at best.
Forward speed seemed about the same between the two canopies, but whoa, did the Cobalt have some serious flare power!
I put about ten jumps on the Cobalt 170 before returning her to Atair. I then called Icarus and asked them what they thought about the sizing difference claims between the Safire and the Cobalt. They confirmed what Dan said. Essentially they stated that the Safire was sized abit smaller for given square footage compared to other canopies. They went on to say that a Safire 169 was more closely sized to a Crossfire 149 or Cobalt 150.
After that I flew a Crossfire 169 and got a similar impresson as the Cobalt when compared to my Safire 169. The Crossfire did seem to loose more altitude when making aggressive toggle turns as compared to the other canopies. It also seemed vaugley more squirrely to minor toggle adjustments, the kind applied on final approach when landing. Nothing, frieghtening, just a little more busy.
A couple of months ago I demoed a Cobalt 150 and put about eight jumps on her. So now this is the supposed apple-to-apple comparision, right? Well, actually, yes, kinda. The Cobalt 150 does seem a better comparison to the Safire 169 when at altitude. The speed of turns seems more comparable to the 169, maybe slightly faster. The over-all subjective experience (seat-of-the-pants) seems to compare the 150 to the the 169 well. However, under my Safire 169 I was wingloading at 1.24 and under the Cobalt 150 I'm pushing 1.43. This is a significant difference and you can tell. Your forward speed is faster and aggressive turns are more ground hungry. Entering the landing pattern ( I still land with staight in approaches) under the Cobalt 150 and things are happening more quickly. At my level and my wingloading I would strongly suggest you be proficient at braked turns or rear riser turns when below 1000' to deal with those "oh shit" situations. An aggressive toggle turn made low under a Safire 169 might have been doable, done under the Cobalt 150 and it just might do you.
Oh, almost forgot. With respect to glide. The Cobalt 150 does have a nice glide ratio. I can't really compare it to the Safire 169 because I didn't directly/consously compare the two in this atribute. I can give you a enlighting example. My wife flies a Spectre 170 that she loads at about 1.1. We did a two-way when I was demoing the Cobalt 150 and opened at 7000' (last load of the day and we wanted some canopy time.). Good thing we opened high 'cause the spot sucked. Way off. So I'm immediately alternating between pulling down the rear rises or setting the brakes to 1/3. Karen, my wife is doing the same thing. We made it back to the DZ without a hitch but it left no time to play under canopy. We were flying close together the whole time and I was able to stay right with Karen even though she had a much lower wing loading. I realize we're comparing a 7-cell to a 9-cell here, but it does illustrate, roughly at least, the kind of glide you can get under the Cobalt.
Keeping the differences in flying charectoristics at low altitudes in mind, I'm more comfortable landing the Cobalt 150 than the Safire 169. The flare under the Cobalt is just so much more powerful and easier to meter out. That's not to say that the Safire was unmanagable. It wasn't. I very rarely biffed a landing under the Safire, ran more than one out though, really ran....It's just that the Cobalt is again, not only more powerful flaring but much easier to meter out.
I've since sold my Safire about two months ago and ordered a Cobalt 150. It just arrived on Wednesday. Unfortunately, the upper skin color scheme is incorrect so I dare not fly her because I want to return her. I guess it's back to demoing to keep my flying addiction happy. Ah life, 'tis you the reason I live and suffer!
Feet up, heads down, blue skies,
Landmissle

[mountainman 0]

Quote

Unfortunately, the upper skin color scheme is incorrect so I dare not fly her because I want to return her.

I can only imagine how pissed you were. I just got my new Safire in and I dont even know what I'd do if that happened. Maybe go ape-shit and fly to Icarus headquarters and go ape-shit there, too.
-------------
http://www.JumpinDuo.com
"oh no. Not another one"-Alienangel

[PhreeZone 15]

I'll agree with him here. I used to fly a Spectre 170 loaded at like .99:1 and down sized to a Cobalt 150. Forward speed is very similar, and the turns are only a touch faster. I'm actually looking at selling the 150 and getting a 135 this winter. The forward speed under it is more what I'm looking for.
As for the glide rate, I pulled right be side a guy with a Stiletto 150 and he sank away from me the enitre way back to the DZ. He's the same weight as me and ended up 100+ feet under me at the end of a 4000 foot glide (lenght of the runway).
I'm not sure what to put here right now.....

[prost 0]

In regards to your statement about comparing landing your competition cobalt straight in at 2.8 as compared to a stilletto, cobalt or a vengence: I think that statement is a little misleading...how many people jump a COMPETITION Cobalt. Would you land a regular cobalt at that wing loading straight in. I know I have landed a Crossfire straight in at 2.4 to one and had no problems. I always make a point to land straight in the first time I ever jump a canopy. I have not jumped at quite 2.8 but I have landed an FX straight in at 2.6. I do not think 2.8 would be a problem. The competition Cobalt is more of this type of canopy and in my opinion should be compared as such.
William

[Aviatrr 0]

Quote

Does anybody else here agree with Dan's claim that Cobalts should be loaded higher than other canopies in order to fly at the same speed?

I recently had a demo Cobalt that was a little bigger than my old Crossfire(150 opposed to 139).. The 150 was the only one I could get in a reasonable time frame, so I jumped it just to get an idea about the canopy.. Man, I felt like I was under a Manta.. That Cobalt 150 was extremely slow(comparatively, of course) and had very sluggish response to toggle and riser input.. I got to jump a Cobalt 135 the following week, and it felt fairly sluggish too.. I felt that I would have to go to a 120 to get anything close to a Crossfire 139..
Do I agree with the claims that a Cobalt at a 1.2 to 1.4 loading are suitable for newbies? No way.. But, that's just one opinion - take it for what it's worth..
Mike

[marcin 0]

I normally fly Atair Impulse 120 (basically the European equivalent of Cobalt, although Dan elaborated earlier on some differences) loaded at 1.8-1.9 (if I wear lead). Straight in approach is newer a problem, but I very rearly do one.
I borrowed it to a friend who newer hooks and flies a 140 BT Pro. He was amased with the ease of handling and the flaring power and wants to buy one. When we flew next to each other (we weight the same) in brakes from long spot my glide was flatter but also horizontally faster, so he was staying behind and below.
I recently put a few jumps on Impulse 95 at 2.2. Similarly stable, faster and surfs like 30 percent longer then a 120. From the second jump I already felt confident with it, although remained careful - at this loading, and at very much lighter loading too- it can easily kill you. I newer flew a canopy smaller then 105-110 before that.
With this 95 I was filming two guys under 135 and 120 canopies (lighter then me) touching end cells and performing intentional simultanous cut away. I was right behind them everybody in deep brakes and I had no problem at all to stay up with them. I guess it proves that the glide is indeed excellent (it also made for a great video!).
I will try an 85 at 2.5 just to see what it can do at that loading, although I do not expect it to be that efficient.
marcin

[SkymonkeyONE 3]

William,
you are correct in saying that this is probably not a fair comparison. Still, Tony Canant flies a STOCK Cobalt 65 loaded at 2.8 and lands it easilly. Before I modified my "stock" Cobalt 75 to the "H"-mod, I was easilly landing it at 2.4, even straight in. Is that more the type of comparison you were looking for?
Chuck
My webpage HERE

[cobaltdan 0]

a note on extreme loadings: jim slaton has test jumped atair alpha/impulse canopies at loading up to 3.6# !!! this is not a competition wing.
stock cobalts and competition cobalts should handle even higher wing loadings.
eric butz of team atair (chuck blue & brian harrell, eric butz) is 260# out the door. his highest wing loading to date is just below chuck's at 2.73# but he has been on me to train for a 4:1 attempt on a stock cobalt!!!
i reluctantly agreed, provided he jumps a trident rig for training. i.e. a strict training regimen, progressively increasing loading. at the 4# loading i would insist he flys our dataloger and performs mock swoops at altitude. he would be required to chop and land under a second main until we see dead consistant swoops on the datalogger (our dataloger can plot out in 3d the flight path flown).
sincerely,
dan
atair

[prost 0]

Thanks Chuck.

[roq 0]

In my opinion the Cobalt is not slower than the other canopies with the same size. Simply, Cobalt is balanced and has a softer and previsible behavior that gives a true sensation of safety, as a 30 year-old automobile ago compared with a current automobile. There are 30 years when you went the speed 50 miles and had the sensation of going to 120 miles, today you go to 120 miles and you seems going to 50.

[cobaltdan 0]

hi roq,
very good point !
i agree with your observation, but note that from our data logger we know that the cobalt out glides (all other skydiving canopies) and is actually slower (given equal loading, in foward flight) than competing canopies.
the end result is pretty cool in that you can swoop farther but at a slower speed.
sincerly,
dan
atair

[freeflir29 0]

"the end result is pretty cool in that you can swoop farther but at a slower speed."
That just may save a life or two some day if it hasn't already.
"and I'm not easily impressed...Ooohh look...a blue car!" -Homer Simpson

[roq 0]

I agree with Dan
I don't have doubt that Cobalt for having gotten a progress and a better technical improvement, that sees him in its behavior, in the opening, in flight and in landing, flies with more safety to an less speed.
Some other canopies always needs more speed for have an safe and acceptable lift and control. It can sees, especially, with turbulence conditions.

[skymedic 0]

Hey dan....good math in the new Skydiving....
Marc
Res Firma Mitescere Nescite

[ramon 0]

Pretty much my exact experience jumping a 135 at 1.7 versus a vengeance. the cobalt was floaty and easy to land (though I'd like longer brake lines on a demo ), vengeance was divey and easy to swoop far and it flies sort of big compared to a stilleto. After I jumped the CBLT 135 I felt it was a good safe canopy for Zennie (downsizing from 150).
bloo skies
ramon
I might have to order a 120 or smaller demo one of these days.