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Hi, I was wondering if anyone had any insight into this. Does the wingload make a difference for slider off jumps? I have a 265 and a 242, and wondering which would be best for a boarder land ff hand held 48" jump. Regarding opening hight. Not easy to tell the difference just by jumping them..

Are they the same kind of canopy?

Larger canopies generally take a bit longer to open (independent of wing loading), but it's more complex than just size or wing loading.

Also, "open" is a bit broad. Are you talking about altitude to bottom skin expansion (when you stop free falling toward the ground) or altitude to pressurization (when the canopy is inflated). If your concern is being able to fly/land the canopy as soon as possible, then bottom skin inlets are going to help quite a bit.

Most of the difference in bottom skin expansion altitudes that I've noticed has been on 300+ size canopies. In my experience, there isn't much difference (probably less than 10 feet) between the 240 and 260 sizes in terms of opening altitudes.

Thanks Tom. The two different canopies are a Troll 245 and a Flik 242. Both vented. So if i understand you right, wingloading seems to have nothing to do with slower openings on very large canopies? Im trying to educate myself for low slider off :) Do you think there will be any difference on these two? Also, a brand new f111 48" would preform pretty much the same as a non vented zp?

the general rule ive used which im happy to know if it works by Tom is that the larger caopies open slower but start moving forward faster, and that smaller ones open fast but take a little more to get going.

I wouldn't expect much difference in opening altitude between those canopies.




I think it's mostly about the size of the canopy--not the wing loading. I have several 300+ canopies and they seem to open more or less the same (slowly, in this context) with jumpers ranging from 180 to 250 pounds.



I prefer unvented ZP PC's for very low (go and throw) jumps because of the lower hesitation rate. I think that F-111 will hesitate more then ZP in this application. F-111 is definitely less porous when new, though, so "brand new" might be ok. Have you tried breathing through the PC to check roughly how porous it feels?

I routinely freefall a flik 308 from 250'. I'm lightly loaded on it and I don't notice a difference in opening height between the 308 and the heavily loaded unvented 260 I used to jump from the same object. I also use an unvented f-111 PC and it seems to work fine, but I check it more thoroughly than my ZP pilots.
When I ask my boys where I opened, they all say, "the same place as everyone else."

which is why i wont invite you down here hayes........
i dont want you "opening" anywhere near the castro district.............

all these starving comedians and yoI've got jokes.

If it matters...from the first post, I think he meant 265....

I asked Stane form Atair about the same thing. The answer was that for the same person the bigger one does indeed open slightly slower but the stall speed is smaller for bigger wing and thus it starts to fly faster and the overall result is better on a bigger canopy.
In other words the smaller canopy will open slightly faster but will stall (because it needs more speed to fly) for longer time and will start to fly forward later then the bigger one

A Troll 245 is actually 265 by PIA specs. They measure it differently.