rhys 0 #1 January 18, 2008 Due to a discussion in another forum. I thought a poll to see what the differences of opinion would be. It is important that we know these kind of things to help us make informed decisions in such conditions. Personally I would rather be under canopy with more loading on a turbulent day. As a tandem instructor I would rather have the 100Kg customer than the 50Kg customer, and I would take the 300Sq ft canopy rather than the 364. what would you do? Sometimes there can be turbulence on calm days but mostly turbulence comes hand in hand with wind. Bare this in mind with you comments and include certain conditions you may have in your area."When the power of love overcomes the love of power, then the world will see peace." - 'Jimi' Hendrix Quote Share this post Link to post Share on other sites
gearless_chris 1 #2 January 18, 2008 Does anyone have a good explanation for why the heavier loading works better? I'm guessing the higher speed creates more pressure in the cells to reduce the distortion."If it wasn't easy stupid people couldn't do it", Duane. My momma said I could be anything I wanted when I grew up, so I became an a$$hole. Quote Share this post Link to post Share on other sites
Mark4 0 #3 January 18, 2008 I don’t think about it in terms of keeping the canopy inflated because if conditions are bad enough that I think the canopy might not stay inflated then I’m staying on the ground! I think more speed means more options because of the increased kinetic energy in the system. With a heavier loading, I need use up less of my control input to sort out a problem. However this only works if you are ahead of your canopy enough to understand what is happening and have time to deal with it. I would much rather fly my Crossfire at 1.7 loading than my Pilot at 1.5 loading in challenging conditions, but I wouldn’t go and jump a even heavier loaded canopy. While I would be confident in good conditions with a heavier loading, the reduced margin for error could be a problem in less perfect conditions. Having said all of that though, if the shit really hits the fan, I would prefer to have as bigger canopy as possible! Quote Share this post Link to post Share on other sites
breadhead 0 #4 January 18, 2008 Cessna 206 versus F14 Tomcat? Quote Share this post Link to post Share on other sites
Sabre1Lucke 0 #5 January 18, 2008 1.Higher aspect ratio wings are more efficient than those with lower aspect ratios. The Lift/Drag ratio is better. Either more lift, or less drag will improve the L/D ratio 2. The reason why airlocks have a reputation for being very stable in turbulence. Because airlocks help a canopy stay pressurized. --> Higher wingload = more pressure in the cells = more stable. Altough, that's what I think Quote Share this post Link to post Share on other sites
diablopilot 2 #6 January 18, 2008 Yes.---------------------------------------------- You're not as good as you think you are. Seriously. Quote Share this post Link to post Share on other sites
flipper 0 #7 January 18, 2008 Also prefer more loaded canopy inthe conditions that you described .... Quote Share this post Link to post Share on other sites
dharma1976 0 #8 January 18, 2008 I voted yes, but have seen situations where I would rather be on a higher loaded conventional canopy than a highly loaded x-brace since I have seen highly loaded crossbraces get all fucked up in really turbulent days Cheers Davehttp://www.skyjunky.com CSpenceFLY - I can't believe the number of people willing to bet their life on someone else doing the right thing. Quote Share this post Link to post Share on other sites
phoenixlpr 0 #9 January 18, 2008 Is this the right time to have a poll about if gravity works? You should have positive load on lines to keep your canopy flying. Not even airlocks would keep your canopy flying in turbulance..... Quote Share this post Link to post Share on other sites
Bolas 5 #10 January 18, 2008 QuoteI voted yes, but have seen situations where I would rather be on a higher loaded conventional canopy than a highly loaded x-brace since I have seen highly loaded crossbraces get all fucked up in really turbulent days Cheers Dave A crossbrace was getting fucked up, but the conventional canopies were okay?Stupidity if left untreated is self-correcting If ya can't be good, look good, if that fails, make 'em laugh. Quote Share this post Link to post Share on other sites
dharma1976 0 #11 January 18, 2008 QuoteQuoteI voted yes, but have seen situations where I would rather be on a higher loaded conventional canopy than a highly loaded x-brace since I have seen highly loaded crossbraces get all fucked up in really turbulent days Cheers Dave A crossbrace was getting fucked up, but the conventional canopies were okay? I watched a very experienced camera guys velo fold up on him at about 2000 feet while he was flying a long it was a fucked up turbulent hot day and he promptly switched to his stiletto. Davehttp://www.skyjunky.com CSpenceFLY - I can't believe the number of people willing to bet their life on someone else doing the right thing. Quote Share this post Link to post Share on other sites
JohanW 0 #12 January 19, 2008 This may be a dangerous discussion without some caveats. The comment about energy in the system makes sense - if you have more energy in the system to work with, you can handle turbulence better if you have the skills to pull it off. There are circumstances where no amount of skill would be enough, and you'd be looking at damage control instead of salvaging the situation. Students would be at this point sooner because of lack of skills. A collapse at 20 feet leaves you no time to salvage anything, and at that point less energy in the system means less impact trauma. A large 7-cell will reinflate and start flying again sooner, and drop you out of the sky with less energy; a small airlocked canopy will keep flying longer but unceremoniously drop you into a newly created man-size crater after that point. If conditions are bad enough to warrant this discussion, the highly loaded more efficient canopies continue flying a little longer, and their probably more experienced pilots may get away with keeping jumping. I'll be at the bar, having this discussion, waiting it out. There's always another day, as long as you're still there for it.Johan. I am. I think. Quote Share this post Link to post Share on other sites
rhys 0 #13 January 20, 2008 Quote If conditions are bad enough to warrant this discussion.... .....I'll be at the bar, having this discussion, waiting it out. Wise words!! "When the power of love overcomes the love of power, then the world will see peace." - 'Jimi' Hendrix Quote Share this post Link to post Share on other sites
billvon 2,464 #14 January 21, 2008 >Higher aspect ratio wings are more efficient than those with lower >aspect ratios. The Lift/Drag ratio is better. Either more lift, or less drag >will improve the L/D ratio Agreed. But paraglider wings have tremendous aspect ratios and are quite unstable compared to our canopies. Thus I think higher AR's are less stable overall. >The reason why airlocks have a reputation for being very stable in >turbulence. Because airlocks help a canopy stay pressurized. I think the primary thing airlocks does for a canopy is provide excellent bracing for the nose, thus improving the normal structural integrity (provided by the interplay of lift, drag and normal force on the lines.) Brian Germain did an experiment where he "disabled" some of the airlocks, thus letting air escape - and the canopy still seemed as stable. For a more recent example, Amy blew her topskin this weekend. She had a two foot long hole in the topskin of the canopy, which severely compromises pressurization. It was a bit bumpy (the usual Perris winter bumps) and she had no problem landing it. >Higher wingload = more pressure in the cells = more stable. Consider the following thought experiment. Cut the outer four lines on your canopy - now try to land it. Now cut a two foot hole in the center of the bottom skin, and try to land it. Which canopy will remain more intact/flyable? Quote Share this post Link to post Share on other sites
