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jonrusso99

Canopy Size and Descent Rate

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Hi all,

I saw a recent thread about unconscious/uncontrolled landings which brought up a new question. Is wing loading the only factor in descent rate here, or does the canopy model make a significant difference?

I am looking for a reserve (for my first rig, Mirage M4) and the three largest options that fit are an Icarus Nano 176, PD 160 and Smart 150. Logic would say that the Icarus would be the safest to land (whether uncontrolled or controlled) but is that necessarily the case?

Thanks in advance!

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A few years ago I demoed na Optimum 160, Nano 160, and Speed2000/190, and all 3 were about 10mph (4.5 m/s) vertical with brakes stowed, and 15 mph (6.7 m/s) in full flight with an exit weight of 210 lb (95 kg). I hope that helps.
Brian

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Wing loading makes a difference, as does altitude, your toggle input (flying in brakes), etc. How you wear your chest strap also impacts descent rate. Loosening the chest strap allows your lines to spread out more, thus creating a flatter wing above you that will generate a bit more lift. Brian Germain has an article out there about this.

Generally speaking, 7 cell canopies descend more steeply than do 9 cell canopies. Do you fly a 9-cell main? If so, next time your at the DZ, ask someone flying a 7 cell with about the same wing loading to fly closer to you in full flight and you should see them sink slowly away from you. At a DZ that I frequent, the 7 cell pilots usually enter the landing pattern first just for this reason.

Just about every reserve on the market is a 7 cell canopy and so it will sink faster than your main if you're flying a 9 cell main. Many canopy manufacturers will send you reserve demos that your rigger can attach to your rig as a main chute for a few jumps - allowing you to fly the model of reserve you're interested in before your buy it. Some companies offer these demos at boogies if there is one near you in the near future.

I've never flown an Icarus or a Smart Reserve, but can say that PD makes a quality product. You may want to give these three companies a call and ask about demo rentals. The below link will take you to the PD demo request page that includes the PD reserve:

http://www.performancedesigns.com/demo-request-form/

Hope this helps.

-JD-

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jonrusso99

Hi all,

I saw a recent thread about unconscious/uncontrolled landings which brought up a new question. Is wing loading the only factor in descent rate here, or does the canopy model make a significant difference?

I am looking for a reserve (for my first rig, Mirage M4) and the three largest options that fit are an Icarus Nano 176, PD 160 and Smart 150. Logic would say that the Icarus would be the safest to land (whether uncontrolled or controlled) but is that necessarily the case?

Thanks in advance!



Are these the sizes that are predicted to fit well, or the biggest?

The biggest that is supposed to be able to fit might be really awful in other ways. Maybe better to get the biggest that can fit just right.
People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

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Of course you’re also considering the optimum and smart lpv, correct?
People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

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Thanks everyone for the help!

Demoing a reserve would be tough right now as this is my first rig and I don't have a reserve already but it is good to know that they will send one out to try out as a main, I didn't think that was an option.

The recommended reserve is a PD 143 (see below for options listed on the mirage site for my model). But I would like to go with the safest option and from what I can tell larger generally equals safer. Note that I am quite new to the sport, 1 year 100 jumps, so have only jumped rental gear up until this point and have a lot to learn about all the gear. I mentioned the Smart 150 only because it is the only used one I can find at the moment which would save me $800-900.

If it is being packed by an experienced rigger, what are the downsides to getting one that is a tight fit?


Pack Volume 300cu.in.

Aerodyne Research Smart 135 – Soft
Aerodyne Research Smart 150
Flight Concepts 145 Cricket
Icarus Reserve 149
Icarus Nano 176 – Firm, No Larger
PD Reserve 143 – Recommended
PD Optimum 160
PD Reserve 160 – Firm
Precision Aerodynamics R-Max 148

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A super tight reserve can make packing a tight main harder and the combination of the two has been implicated in some delayed reserve deployments. Also the comfort factor, a brick is less comfortable on your back than a pillow.

Forget unconscious reserve landings, it is extremely rare (like I can't think of one off the top of my head where the jumper wasn't already mortally injured), and no matter what it is probably going to suck for you if you survive it. It's impossible to prepare for all of the ultra rare things that can go wrong. Don't get me wrong, I worried about it too when I was <100 jumps, but now, other much more likely to kill/maim me things are my primary concern.

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OldGregg

A super tight reserve can make packing a tight main harder and the combination of the two has been implicated in some delayed reserve deployments. Also the comfort factor, a brick is less comfortable on your back than a pillow.



Too tight also puts more stress on fabric/stitching/stiffeners/grommets.

Too tight also puts more stress on your rigger. You do not want your rigger to regret agreeing to pack your reserve because it is "one of those". Much better to have your repack welcomed because your reserve fits the way it is supposed to.
People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

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Wing-loading is the most important variable - when predicting rate of descent.
Brake position (stowed or flared) is the second, with line trim being the third. Line trim is set at the factory when they cut suspension lines. Some canopies are trimmed more steeply (nose-down) than others.
Modern reserves have similar opening and flight characteristics.
You made a decent choice with a used Smart 150. I have packed hundreds of Smarts that saved a few customers.
I have also packed hundreds of PD Reserves and a handful of PD Optimims. I really enjoy packing Optimums because the fabric compresses so easily. I can consistently pack an Optimum 176 into a container that was snug on a PD 160. PD set the standard almost 30 years ago and all other manufacturers struggle to improve reserve performance by a percentage point or two.

The only way to buy a double-digit (say 15%) improvement is buying a low-pack-volume reserve like a PD Optimum, LPV Smart of Icarus Nano. They will allow you pack an additional 15 square feet of reserve into your existing container (175 vs. 160 square feet).
If I were buying new, I would purchase an Optimum 190 or LPV Smart 190. If buying used .... a lightly-used PD 176.

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A decent list.
The only canopy I would avoid is the Cricket 145 because it is mid-1980s technology and was never meant to be loaded more than 1 pound per square foot. If you over-load any reserve, we will refer to you as “that stupid, fat white man!”
PDs, Optimums and Smarts are all well-respected reserves.
I have only packed one or two Icarus reserves.
I only have one jump on an R-Max 188. I loaded it right to the corner of the chart, but it still set me down softly. I woukd never buy an R-Max 118, but woukd seriously consider buying an R-Max 170-ish.

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For what it is worth I've had a ride on a Smart and an Optimum. The Smart got the job done but I wasn't a fan of the landing, the OP felt like a slightly sluggish sport canopy with a good strong flare. Both deployments, at least on the reserve end of things, were uneventful.

OPs also flew well enough that some folks were jumping them as mains (PCA added) so they could wingsuit with their <120sqft sized containers. It was heavily frowned upon and I haven't seen anyone do it in a while, but it did work.

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I would look into the "Speed" reserve as well. From what I understand it is the smallest packing and has a pretty low price tag.

I know a rigger that has two, I think when I need to buy another new reserve, that is the route I'm going to go. I just haven't had the need to get a new one since I found out about them.

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