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drewcarp

Brian Germain WL Chart

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So I have always tried to be pretty conservative when it comes to my choices skydiving especially with gear and the kind of jumps I do, or at least I thought. Now I'm looking at Brian Germain's WL chart and realized that my "conservative choice" will significantly exceed his chart. I have no desire to be an aggressive canopy pilot and I have no desire to swoop, I just want a soft landing. I don't mean to knock the chart or Brian as I think it's a really good thing and he is a very good guy to listen to but it says I should be flying a 270 until 120 jumps, does no one really follow this chart or is my situation just unique? Here is the breakdown.

Weight: 190 w/o gear, guessing 220 with gear
+
Chart says add 10sf per 2000 feet in density altitude. I jump at mile high in CO (8000ft density alt. on most summer days) = ADD 40sf.

= 270 or at MINIMUM a 248 until I have 120 jumps?

So far I have jumped...

280 - 20 jumps
260 - 5
240 (Nav) - 5
230 (Spec) - 10
210 (Storm) - 20

I don't wanna jinx myself but I have stood up all my landings fine except number 1 and 4.

I ask because I just bought a 210 Pilot with a PDR193. Now that I think about it I think I might rather have a 230 in there but I would still be busting the chart by 20%.

Should I really be shopping for a 260 for my first canopy to stay relatively conservative? I haven't seen anyone jumping a 260 that isn't still in AFF, what's the deal? Is the chart not as linear or important to follow closely in the upper ranges or should I look for something bigger? Has anyone fit any 230's into a Mirage M6 in a very dry climate?

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The chart is only page 1 of a 22 page document.

Make sure you read and can perform the maneuvers listed starting on page 7.

The best time to consider downsizing is when you do everything with the canopy you already use.

http://www.bigairsportz.com/pdf/bas-sizingchart.pdf
"Where troubles melt like lemon drops, away above the chimney tops, that's where you'll find me" Dorothy

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For starters, WL to the chart works best in the middle fo the 'bell curve'. If you were a 165lbs, it would be right in the ballaprk for where you need to be. If you take that same formula and apply it to higher weights (like yours, or above) you'll find the chart a hair on the conservative side.

Likewise, if you scale it down to a jumper who weighs 120lbs, than the chart isn't conservative enough, as it would have a new jumper on a 120 or 135, and for various reasons that's not a great idea, even at lighter wingloadings.

Back to your situation, I also don't think you need to add sq footage for the hottest day in the summer. You could probably use the altitude at standard temp, which is 5000ft, and just add 20 or 30 sq ft for density altitude. In that case, you're looking at a 220 to 240 to be in the range of the chart.

Again, back to the law of averages, if you happen to be an above average student, and downsized gradually with instructor oversight, you might be just fine with your 210. On the hot summer days with no wind, you might be wishing you had a 220, but that's a chance you'll have choose to take or not.

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Quote

does no one really follow this chart or is my situation just unique?



Short answer: Yes there are people following this chart due to the fact that chart is a copy of swedish rules.

But:
We dont have all the requirements he does.
Also nothing about altitude of dropzone, and that could be because its not that big problem here.
Basicly we have the chart and some other rules about what type of canopy.

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