billvon 2,396 #51 June 13, 2011 >Wrong. More speed, more pressurization Pressurization means almost nothing. If your wing is unpressurized it has no resistance to negative G loading. If your wing is pressurized it still has no resistance to negative G loading. >and keep your lines under tension. This _is_ important. Line tension is what gives us stability, and speed can prevent a wind shear from behind from causing a spurious stall. This must be balanced against the benefits of slowing down to reduce the effect of that same wind shear. Which is why in most cases full flight (which is still pretty slow) or slight application of brakes (to keep tension in brake lines) is the ticket, with an immediate input of 1/4 to 1/2 brakes if the canopy does collapse. Quote Share this post Link to post Share on other sites
champu 1 #52 June 13, 2011 Quote ...and more importantly keep it flying the DIRECTION YOU WANT IT TO GO, usually straight ahead of you. This is especially important low to the ground. Quote 3-MOST IMPORTANTLY, keep the parachute flying the direction you want it to fly. EVEN IF IT COLLAPSES, while it is inflating, keep the parachute facing the direction you want it to go, ESPECIALLY if you are low. Quote ABOVE ALL- keep it flying the direction you want it to go. and once you get low, there is only ONE direction you want it to go, and that is straight ahead. One thing I'll add to Calvin's posts, in case it wasn't clear from reading them, is that you want to keep the canopy flying in the direction you want to go. When you encounter wind shear or turbulance it will change the way the canopy responds to control inputs. Sometimes only a little, sometimes a great deal. But it will still respond to control inputs, so it's on the pilot to make sure he or she improves the situation rather than letting it get or actively making it worse. Instead of thinking, "I have to go to quarter breaks" or something of that nature I think, "keep flying, you totally got this." Quote Share this post Link to post Share on other sites
Calvin19 0 #53 June 13, 2011 QuoteQuoteQuote>Structural damage and overspeed during a turbulence/windshear >encounter are not appliable to airfoils used in Skydiving. Sure they are. While canopies are almost (for our purposes) infinitely strong in the positive-G direction, they have almost no strength in the negative-G direction. Wind shear that causes negative G loading in an aircraft will cause severe turbulence and knock people around the cabin, but usually the airfoil will survive. Our airfoils will collapse. Agreed, that was where my 1/4 brakes penetration method came from. Slower penetration equals less violent turbulence. Wrong. More speed, more pressurization and keep your lines under tension. Do not give up your speed... what does speed do for you? unless you are flying something with a very high wing loading, flight speed is easily recoverable. Some guy a few posts up compared aircraft "penetration" speeds to canopy collapse. While not directly transferable, he did have a point that high speed penetration=more "violent" turbulent effect on an airfoil. There is no "save all" flying through turbulence technique, but I strongly believe the best thing to do is just fly the parachute, have tension on the brake lines to be able to feel the wing and what it wants to do. keep even pressure on the toggles and weight shift. as for your "don't give up your speed" comment. Compare turbulent air to turbulent water you are water-skiing on. If the waves are really big, you cannot go fast enough to just skip over them, you have to (sometimes) slow down, bend your knees, and absorb the waves. If you are going too fast and your skis lose contact with the water for a long enough period of time, they no longer can be used for control and the skier crashes(or parachute collapses). Of course you cannot go too slow, because the ski/wing will stop working (sink/stall). you need to find that balance and fly(control/balance) through it. on the same page: Paragliders are FAR more susceptible to collapse than any parachute, and Paraglider pilots fly through more drastic turbulence than skydivers on a regular basis. We control our wings by this"active flying" technique I have described in other posts.. It also should be noted that paragliders are "designed" to partially collapse in some situations to absorb certain turbulence, and yield to pilot error in active flying. The BIGGEST issue when testing a paraglider is its ability to maintain a heading through a collapse. Quote Share this post Link to post Share on other sites
rehmwa 2 #54 June 13, 2011 Quote>Which is why in most cases full flight (which is still pretty slow) or slight application of brakes (to keep tension in brake lines) is the ticket, with an immediate input of 1/4 to 1/2 brakes if the canopy does collapse. this is the ticket for today's canopies the old "keep it in 1/4 brakes through turbulence", I believe, is from when the canopy inlets weren't as dialed in as today's canopy and a bit of brakes was needed to keep the nose "open" or you'd lose a cell or two in turbulence. so the right answer is "it depends on the canopy my old Maverick? I'll hold a bit of brakes in turbulence My Stilettos? I'd rather have a lot of speed to cut through the yuck - let it fly and be ready to fly through any issues (just taking the slack from the steering lines would be the MAX I'd put in for no reason, but I don't even like that) IMO, YMMV, RSVP, PDQ ... Driving is a one dimensional activity - a monkey can do it - being proud of your driving abilities is like being proud of being able to put on pants Quote Share this post Link to post Share on other sites
phoenixlpr 0 #55 June 13, 2011 Quoteas for your "don't give up your speed" comment. Compare turbulent air to turbulent water you are water-skiing on. If the waves are really big, you cannot go fast enough to just skip over them, you have to (sometimes) slow down, bend your knees, and absorb the waves. If you are going too fast and your skis lose contact with the water for a long enough period of time, they no longer can be used for control and the skier crashes(or parachute collapses). Of course you cannot go too slow, because the ski/wing will stop working (sink/stall). you need to find that balance and fly(control/balance) through it. What keeps your canopy in shape? Is it internal pressure? What is the source of the pressure? Is it your airspeed may be? I agree with active flying and keeping the brake line tight, but flying in full speed. Quote Share this post Link to post Share on other sites
Calvin19 0 #56 June 13, 2011 Quote What keeps your canopy in shape? Is it internal pressure? Yes, kinda. "ram air" pressure at the leading edge openings is what "inflates" the wing. BUT... what keeps you FLYING is lift, from angle of attack. anywhere above stall the wing should have plenty of internal pressure. Line tension from lift is what holds your canopy above you, this is controlled by the angle of attack of the wing. NOT the internal pressure. 1/4 brake idea comes from paragliding, where we use adequate pressure on the brake lines so we can "give and take" as we fly through rough air. I doubt the difference between full flight with brake line tension and 1/4 brakes on a parachute matters very much if at all. So, yeah, full flight with brake line "tension" to feel and be ready to control the wing would be just fine. -SPACE- Quote Share this post Link to post Share on other sites
phoenixlpr 0 #57 June 13, 2011 Quote I doubt the difference between full flight with brake line tension and 1/4 brakes on a parachute matters very much if at all. Sure there also no difference in landing if you start from 1/4 breaks, right?? Quote Share this post Link to post Share on other sites
Calvin19 0 #58 June 13, 2011 Quote Quote I doubt the difference between full flight with brake line tension and 1/4 brakes on a parachute matters very much if at all. Sure there also no difference in landing if you start from 1/4 breaks, right?? yeah yeah yeah. Speed is good, but control is better. Rather be near stall and pound in than out of control and hauling ass. I guess we are just splitting hairs now. I imagine that the majority of experienced canopy pilots deal with turbulence just fine. Target audience here is people less familiar with flying stuff. Don't turn too low and flare. It's all the same. Quote Share this post Link to post Share on other sites
billvon 2,396 #59 June 13, 2011 >My Stilettos? I'd rather have a lot of speed to cut through the yuck I agree with most of the above, but wanted to point out something about the "cut through" thing: I have heard people say "I hold front riser to 'cut through the turbulence' so it doesn't affect me as much. " Using more speed to "cut through" turbulence works about as well as a car accelerating to 70mph to "cut through" potholes, or a ship going as fast as it can to "cut through" heavy seas. Modern canopies are designed to be very stable in their normal (i.e. no control inputs) configuration. That is almost always the best configuration to fly them in turbulence; adding speed artificially takes them out of that normal configuration and will, in general, make them less stable. (I know you didn't say anything about the front risers, I just wanted to point that out in case anyone else was thinking about that.) Quote Share this post Link to post Share on other sites
