Whats the difference between a 7cell and 9cell canopy?

[bluesky1977 0]

My bro got me a 7cell Spectre 230. I have never flown a 7 cell canopy before. How is this different from a 9cell canopy? (Opening, Flying and Landing, Glide path etc.). Any feedback on this particular brand would be great. The smallest canopy I have flown so far is a PD Silhouette 230 9cell. Should I expect Spectre to be different from a Silhouette?

Thanks.
--Vamsi

[sabr190 0]

I think you would get a better response in Gear and Rigging forum.

Greenies??

"The needs of the many out weigh the needs of the few, or the one" - rehmwa

[mnealtx 0]

I'm buying my first gear, and I've read all the comparison threads and gear reviews. About the only bad thing I recall reading about it was some people thought it snivelled TOO long...

From PD's manual for the Spectre:

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The snatch force of a Spectre will be similar to other canopies of the same size. All sizes of the Spectre have a relatively long snivel and slow inflation speed. Larger Spectres tend to inflate a bit more slowly than smaller ones. Jumpers who enjoy soft, comfortable openings tend to be very happy with the Spectre.

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Straight Flight at full Glide: The Spectre flies at about the same airspeed as other canopies such as the original Sabre, the Sabre2, and the Stiletto. Many jumpers do not expect a seven-cell canopy to glide as far as a comparable nine-cell, but at full glide the Spectre actually has a slightly flatter glide angle than some nine-cell canopies, including both the original Sabre and the Sabre2. Remember that accurate comparisons can only be made between canopies that are the same size and flown with the same wing loading. Other factors we described above in “A Note on Comparing Canopies” may also affect your impression of the way a canopy glides.
Straight Flight in Brakes: Many older ram-air canopy designs tend to descend at a steeper angle or “sink” when flown in brakes. Canopies made for disciplines such as traditional accuracy are also designed to do this. Modern “high performance” canopies are usually designed with different characteristics in mind, and may perform differently when flown in brakes. Many canopies being used today, including the Spectre, actually glide farther or “float” when flown in brakes, although the Spectre is not quite as “floaty” in brakes as canopies such as the Sabre2 and Stiletto.

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Toggle Turns from Full Glide: If you have been flying a rectangular canopy like the original Sabre or original PD 9-Cell, you will probably enjoy the responsiveness of the Spectre. The Spectre will turn more quickly and smoothly than a rectangular canopy, with less toggle pressure. Toggle turns on the Spectre feel similar to those on the Sabre2, although you may notice some differences. A Sabre2 requires less toggle input to start and maintain a turn, while the Spectre actually turns in a tighter radius.

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Stall Characteristics: Depending on how much you weigh, you may not be able to stall a Spectre even if you hold the toggles all the way down. Quite a few skydivers, even very knowledgeable and experienced ones, believe that you must be able to stall a canopy with the toggles all the way down in order to land it correctly. This belief does not apply to many canopies, including the Spectre. When a canopy actually stalls, its lift decreases dramatically and its rate of descent rapidly increases. A stalled canopy is not really “flying.” If you want a soft landing, you want your canopy to keep creating lift and maintaining a low rate of descent until your feet are on the ground. If a canopy stalls while landing, it may set you rather abruptly on the ground. If you adjust your steering toggles so that your canopy is easier to stall, it may actually become more difficult to land softly. The Spectre will reach a fairly low airspeed before stalling. As with many canopies, the Spectre may take several seconds to fully re-pressurize after recovering from a full stall. Holding the toggles down at between ½ and ¾ brakes will help the canopy re-pressurize more quickly.
Landings: The Spectre tends to have a lower flare point or “sweet spot” than some of our other zero-porosity canopies, meaning you will need to pull the toggles a bit farther on the Spectre to stop your descent. If the flare is a bit slow, the Spectre tends to exhibit the more traditional seven-cell type landings, where the forward speed bleeds off quite well, but the descent rate is not completely stopped. If the flare is more efficient, with the toggles coming down to the sweet spot a bit more rapidly, the canopy will “plane out” and fly level with the ground quite nicely. Other canopies such as the Sabre2 are designed to plane out more easily, and reach level flight even if the flare is a bit slow. Jumpers who want this type of performance may prefer a canopy like the Sabre2. Other jumpers might prefer the combination of “high performance” characteristics and traditional seven-cell performance that is provided by the Spectre.
Aggressive Approaches (High-Speed Approaches): As we mentioned earlier, the Spectre loses more altitude in a turn than some other canopies. By comparison, the PD Stiletto pulls out of a dive relatively quickly. As with most canopies, smaller sizes dive more in turns than larger ones. It is important to consider differences like these when making an aggressive, turning approach on a canopy that is new to you. Even if you have made hundreds or thousands of these approaches, it is best to be cautious when trying a new type of canopy or a smaller size than you are accustomed to.

Mike
I love you, Shannon and Jim.
POPS 9708 , SCR 14706

[Jskydiver22 0]

I have flown a 7 cell spectre 150 and a sabre2 135. Im still way new at this sport with only 250 jumps so im sure there are other people that know way more about the subject but here are my opinions.

My spectre had a steeper approach to landing and i never got the distance that i do now on my sabre2. It seems like i can get back from long spots a lot easier on my sabre2.

The two canopies that you are comparing are a lot different. The Silhouette is a hybrid canopy that is part F-111 and part Zero-P, i believe it is top skin F-111. It is also more of a student style canopy. The Spectre is completely Zero-p it is also slightly tapered so you will notice a lot more responsiveness from it. It will probably fly faster and crisper than you are used to.

Those are just my opinions. Again...i suggest that you talk to someone who knows a lot more about the subject than I do.

Have fun on your new spectre.

--I don't even know enough to know that I dont know--

[slug 1]

2 Cells

R.I.P.

[bodypilot1 0]

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2 Cells

Would that be 1 cell added on each side, or both cells on the same side there Einstein?


Ed

www.WestCoastWingsuits.com
www.PrecisionSkydiving.com

[riggerrob 643]

The two canopies that you are comparing are a lot different. The Silhouette is a hybrid canopy that is part F-111 and part Zero-P, i believe it is top skin F-111.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Correction: Silhouettes have ZP top skins with F-111 bottom skins which means that they fly like ZP canopies, but are easier to pack.
This material combination is also popular with tandem packers, but the poor, dumb tandem instructors do not notice any difference in how the canopies fly.

[darkwing 5]

Your question is far more open ended than you think. Maybe the simplest answer is that if you have two otherwise identical designs: same airfoil, same planform, same aspect ratio, same area, etc. and build one using 9 cells and the other using 7 cells, the 9 cell version would be a more efficient wing, but would have more pack volume, due to seam and line bulk.

There is very little you can say about intrinsic differences other than that.

-- Jeff
My Skydiving History

[Remster 30]

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same airfoil, same planform, same aspect ratio

Thats the big diff... most 7 cels have a smaller aspect ratio. (and no, I'm not including xbraced in this...)

But I agree, you're better off comparing more specefics: like canopy A vs B...

Remster

[bob.dino 1]

I've no experience with a Silhouette, but I've got about 160 jumps on my Spectre 190.

Nice, smooth, slow openings. Very forgiving of shit body position and less-than-perfect packing techniques.

[bluesky1977 0]

Thats great to hear. Thanks to everybody else for their replies. This is great info...

--Vamsi