skibumb453 0 #1 June 28, 2006 Two other instructors from Flyaway Las Vegas and myself recently made a trip to Denver, Co for various reasons, one of those was to check out the new tunnel there. No more than an hour after the last one of us landed we were at the tunnel checking out their facilities. We weren't even planning on flying that day but the wonderful people at the front counter managed to squeeze us in for a short session, by bumping a group that the owner Norm had brought in. What great customer service! Over the next five days we managed to fly at least 15 minutes each day. How could you not with such fabulous wind and great personable instructors. I just want to say thanks to Flip, Norm, Chris, the Derek's and to all of the great staff at SkyVenture Colorado. You guys rock and I can't wait untill I get a chance to come back and fly with you guys again. And to all others if you get the chance to fly SV CO don't make the mistake of passing up such a great opportunity. Peace, Pots, and Microdots, Brett and the "Flyaway Boys" Don't disrespect just because you can't hang in my tunnel. Here's to blue skys and cool recirculating tunnels. Quote Share this post Link to post Share on other sites
sartre 0 #2 June 29, 2006 QuoteI just want to say thanks... to all of the great staff at SkyVenture Colorado. You guys rock and I can't wait untill I get a chance to come back I second that! I live in the area, and whenever I go there, to fly or just watch, I am greeted by nothing but friendly faces. And excellent coaching. Quote Share this post Link to post Share on other sites
bhammond 0 #3 June 29, 2006 well there always ying to the yang, Ive been holding my tounge for a bit, I went to the skydivers fly party and was a bit under whelmed granted they were slammed with people and busy as hell I was watching the tunnel speed and it was on the slow side 100-105 but there were alot of small people so I figured ok , when it was my time to get in there I was wearing my own RW suit and felt it on the mushy side when I motioned to the operator " a obvious thumbs up as in speed this up " I got nothin but a "instructor " saying I had bad body position... BS I know slow and I would bet I was in the same 100-105 air they were dishing out ..... I was disapointed to say the least. I dont think Ill go back.... Quote Share this post Link to post Share on other sites
tdog 0 #4 June 29, 2006 Quotewell there always ying to the yang, Ive been holding my tounge for a bit, I went to the skydivers fly party and was a bit under whelmed granted they were slammed with people and busy as hell I was watching the tunnel speed and it was on the slow side 100-105 but there were alot of small people so I figured ok , when it was my time to get in there I was wearing my own RW suit and felt it on the mushy side when I motioned to the operator " a obvious thumbs up as in speed this up " I got nothin but a "instructor " saying I had bad body position... BS I know slow and I would bet I was in the same 100-105 air they were dishing out ..... I was disapointed to say the least. I dont think Ill go back.... Wow... That same night (both nights of the skydiver parties) my friend flew the tunnel at full speed on his belly... We are talking enough air to freefly head down in. The instructors were freeflying in a stand around him, and he was aware that spotting at those speeds would be challenging for the instructors, so if he corked he was told what they expected him to do... The instructors also have seen him fly/coach for hours so they know his skills and he has earned their trust. I never have felt the tunnel to be slow - unless I have asked it to be. At the party I was flying pretty fast. But, I know the instructors a lot of times like to see great body position on the net and will turn up the speed once you nail the position and show stability... Quote Share this post Link to post Share on other sites
diablopilot 2 #5 June 29, 2006 100 to 105 is a pretty good clip for most people in the tunnel (wuffos are usually between 90 and 100). I can sitfly at that speed. Remember you're not wearing a rig and it makes a difference. And I have seen plenty of people with a bad body position "ask" the controller for more air and not get it. If you look sketchy and unstable (as people fighting to stay off the net often do) then you'll probably not get more air, especially if they have never seen you fly before. From what you've described, the mistakes you made were, 1) flying in a body position to stay off the net and 2) asking the controller for more wind. If it feels too slow to fly, then let yourself down to the net in a good arch. Cupping or flying the whole dead spider thing just doesn't work as the instructor is now watching carefully for signs of a rollover that he/she will be forced to spot. Now if it were you, would you rather catch 200+ lbs of human falling from 4 feet or 10 feet? Secondly, don't ask the controller for changes, ask the instructor. He/she is the one that is responsible for what happens in the tunnel and while they work as a team, the instructor has final say over what happens. So next time, go to the net, arch, smile and before you even ask for it, I'll bet you have more wind.---------------------------------------------- You're not as good as you think you are. Seriously. Quote Share this post Link to post Share on other sites
4wayFly 0 #6 June 29, 2006 QuoteI was disapointed to say the least. I dont think Ill go back.... Surprised...they have always been great for me... I guess as JP says, you just have to know how to ask Any of you guys going this weekend for the Kirk Verner/ Gary Beyer Airspeed tunnel camp? Quote Share this post Link to post Share on other sites
Zoso 2 #7 June 29, 2006 Interesting factoid I recently learned at Skyventure Arizona: Because of the venturi effect of the tunnel, the air you fly on is thicker (compressed) compared to the same air outside the tunnel. Therefore you need less actual airspeed than normal for any given body position. Quote Share this post Link to post Share on other sites
doug316 0 #8 June 29, 2006 QuoteInteresting factoid I recently learned at Skyventure Arizona: Because of the venturi effect of the tunnel, the air you fly on is thicker (compressed) compared to the same air outside the tunnel. Therefore you need less actual airspeed than normal for any given body position. Although it sounds logically correct, as if the air is squeezed into a smaller space, the opposite is in fact true. The venturi effect means that as the path narrows, the airspeed increases while the pressure decreases. This is the same principal that allows an airfoil to generate lift. Quote Share this post Link to post Share on other sites
billvon 2,380 #9 June 30, 2006 >Because of the venturi effect of the tunnel, the air you fly on is > thicker (compressed) compared to the same air outside the tunnel. > Therefore you need less actual airspeed than normal for any given > body position. Uh oh, rarefied air molecules are making an appearance! The venturi effect refers to how apparent pressures are DECREASED when a fluid is forced through a narrow opening. That's how carburetors work. You don't feel that effect when you are in the tunnel, although you might feel it near the door when you are outside the tunnel. You fly your body based on IAS, or indicated airspeed, rather than TAS, or true airspeed. IAS is what an airspeed indicator reads, and it's the amount of force you feel when you stick your hand in the tunnel. IAS is what must be maintained to be able to fly in a certain body position. TAS is how fast the air is actually moving; that's not as important for tunnel usage (although it is important for tunnel _design._) During operation, the tunnel is sucking air in from the bottom. That means that if there's another way for it to get air (like through an open door) it will suck air in through there too. Which is one reason the tunnels are sealed when they're operating. All that means that pressures are reduced within the tunnel when it's operating. (Not by very much though.) Quote Share this post Link to post Share on other sites
tdog 0 #10 June 30, 2006 I notice that I can fly much slower in the tunnel... I think a lot has to do with the fact we don't wear 30 pound rigs in the tunnel... But I also wonder about the deflection of air around a person... In the sky, the air can go anywhere it wants. But in a tunnel, it has to squeeze by the person and the glass... I think the same can be true in the sky - you get an 8 way formation and it starts to go slow because the air is not free around each person and hits the other people in the formation as it deflects... So - I wonder if that also effects flight speeds??? I know a 4way that gets huge and covers most of the surface area really makes changes to wind speeds... Never the less - back to thread topic... Yes, the Colorado tunnel has a bunch of great people (as most tunnels do) working at the tunnel... Did you see the article in Skydiving Magazine this month about SVCO? Quote Share this post Link to post Share on other sites
diablopilot 2 #11 June 30, 2006 Quoteyou get an 8 way formation and it starts to go slow because the air is not free around each person and hits the other people in the formation as it deflects... You get a slow down because the air getting to the power section in the top fan designs (like Arizona) is not "clean" there for the fans are not efficient. One of the advantages to the SV recirculating design is the fans being placed 90 degrees to the flow of the chmber and having to turn the air to them thus cleaning alot of the "burble" effect out of it.---------------------------------------------- You're not as good as you think you are. Seriously. Quote Share this post Link to post Share on other sites
skibumb453 0 #12 July 1, 2006 I love how a post that is just suppose to give a shout out and say thank you turns into a discussion about the venturi effect. Skydivers are awesome! Don't disrespect just because you can't hang in my tunnel. Here's to blue skys and cool recirculating tunnels. Quote Share this post Link to post Share on other sites
4wayFly 0 #13 July 1, 2006 QuoteI love how a post that is just suppose to give a shout out and say thank you turns into a discussion about the venturi effect Yup - nerds! Quote Share this post Link to post Share on other sites
mdrejhon 8 #14 July 4, 2006 [quiote]If it feels too slow to fly, then let yourself down to the net in a good arch.That's the cue. When wind tunnel operators see you bellyflying touching the net, they bump up the wind speed slightly. The only time I had to signal an air change is when the wind was too fast and I was arching hard just to keep up with the speed. They'd rather not speed up the wind on an unfamiliar skydiver unless you've proven yourself by challenging yourself to bellyfly as close to the net as possible, touching it with belly. Quote Share this post Link to post Share on other sites
riddler 0 #15 July 23, 2006 QuoteAll that means that pressures are reduced within the tunnel when it's operating. (Not by very much though.) And to validate this with practical experience - I have a Neptune that is directly mounted to my glove (with four screws) for jumping. I use it in the tunnel too - usually, they make me take it off, but sometimes they are OK if I wear it. When I do, it usually reads "very slow climb", and the logbook will often read it as a 600 ft skydive for 40 to 50 minutes.Trapped on the surface of a sphere. XKCD Quote Share this post Link to post Share on other sites
