hi, all - I'm trying to understand how PD derive wing-loadings for the Sabre 2. their web-site quotes weights for experience levels which work out around at wing loadings of 1.3 for "exp" and 1.6 max.
I usually jump a 170 at WL1.4 (240lb exit). I've also tried the 150 (WL1.6) and 135 (WL1.8).
I preferred the 135, but I wonder why PD quote such "low" WLs. is it structural or because the aerodynamics get screwy? or because they'd rather sell me the Katana? thanks Richard
I can't speak for what PD does in regards to its published numbers. That would be worth an e-mail or a call.
My personal experience is that for high performance flight 1.4 is where it really starts to pick up in performance. This is up to about 1.7. After that the performance really seems to taper off. It gets faster, but the canopy just doesn't fly as well as it did at the "lower" wingloadings.
With the Katana I found up to 1.9 the canopy rocked, at 2.1 and above it tapered off hard.
It makes sense. You jump a Sabre2 and learn how to really fly a canopy, downsizing with the canopy until you're at 1.7, then you move over to the Katana at that wingloading and move on up in wingloading until you're at the 1.9 range and move over to a Velo. Then move up in wingloading until you're at the wingloading that you want for your personal goals and ability.
There are advantages and disadvantages to higher wingloadings and it all depends on where you want to do and what you can do.
Thanks for the thoughts. I emailed PD a few weeks back, but didn't get a reply beyond ackowledging that it was a design question.
I barely get 200 jumps a year so I'm not going to pretend I'm heading for a Velo (I'd love to try one just to know what it feels like, though) or even pushing beyond WL1.8
I like to get out at 5-8k and stall and dive the hell out of it. the coolest thing about the 135 was that hitting the brakes and then leaping on the front risers (slightly offset to initiate a turning dive) put me back into freefall for a couple of seconds. then, as the riser pressure blistered my hands, I could keep the turn going through the harness. my Neptune would go back into freefall and then show dive speeds of 100+fps
to land, I go for 90 degree (from 350 feet) or 270 (from 500) with 5 secs before levelling off with rears or brakes. ie reasonably conservative, but, according to PD, hideously overloaded. when I tried the Stiletto 150, I brought the 90 turn down to 290 feet because it recovers so fast, but I didn't like the oversteer of the Stiletto compared to Sabre 2
I emailed PD a few weeks back, but didn't get a reply beyond ackowledging that it was a design question.
Hang in there... I sent them an email once with a technical question, and it took a while for them to get routed to the correct person in the company, and for me to get a reply... but when it did, it was a reply from John Leblanc, with a very detailed explanation of the question at hand! Their customer service generally rocks!
hi, all - I'm trying to understand how PD derive wing-loadings for the Sabre 2. their web-site quotes weights for experience levels which work out around at wing loadings of 1.3 for "exp" and 1.6 max.
With the Stiletto and Spectre the maximums (your math is wrong on the Sabre 2) are around the limits where I'd want a canopy with better slow-speed flight characteristics when jumping with density altitude.
I put 600 jumps on my Stiletto 120 with suspended weights between 170 and 205 pounds (mostly some where around 190-200) and density altitudes from about 0 to 9000 feet (100-150 sea level jumps; I think I did 3 big sea level boogies when I mostly jumped my Stiletto).
I spent some time with a Spectre 135 with 200 pounds of me after herniating a disc at elevation (204 pound "maximum") and it was getting to the same place. Better than a square but not quite enough bottom end under sub-optimal conditions when approaching the limit.
Anecdotally, guys at sea level where canopies fly over a size bigger often seem to go a size smaller before they complain.
I suspect Dave's right on the expert column being where it gets interesting.
In Reply To
>or because they'd rather sell me the Katana?
Given enough currency (a layoff after herniating L4-L5 sneezing and moving twice to someplace with mediocre weather were bad for my piloting skills) and a suitable landing area you can land many heavily loaded canopies (this is relative) with at most a couple steps (fly a low approach and pop it back up to the target, or slide to a stop on a nice grassy surface). Don't get that right and you'll be running, and most people don't want a canopy that leaves them with that either/or choice on every approach (it's too much work).
(This post was edited by DrewEckhardt on Mar 25, 2008, 1:30 AM)
