cpoxon 0 #1 October 31, 2003 A couple of weeks ago I was at the very large legal wall in Northern Italy, to increase my meagre wingsuit BASE experience. This is the same wall where Jari and Robi first met and first BASE jumped their wingsuits. This is the same wall as the amazing video you've probably seen with Robi This wall is ideal for wingsuit jumping as it is 4000 feet vertically to the landing area and very skilled flyers can achieve delays of over a minute. However, due to the sloping talus and forest below, without the aid of a wingsuit, even the most the best can achieve, albeit with Pantz, is 21 seconds I took a ProTrack with me, so that I could download a profile of the flight afterwards. As per the instruction manual (page 43), I set the Dive Type to 11 - SPC (Special), where I could set the altitude of the exit point. However, when I landed, the ProTrack was indicating a much shorter freefall delay than my camera recorded and a much higher deployment altitude than my eyes were telling me. I surmised that this was due to the unit not being in Dive Type 10: SLOW (Slow) mode and the wingsuit flight had tricked the unit into thinking the canopy had deployed. This happened again on a second jump. See the attached graph CraigMBOct2003_2.jpg So, on the third jump, with nothing to lose, I thought I'd try something. First I set the altitude of the ProTrack at the exit point using the SPC mode. After the unit had adjusted to the altitude, I then went back into it and switched it to SLO mode. Upon landing, I was happy to discover that the unit was reporting a more accurate freefall delay and deployment altitude. When I got back and downloaded the data I was sort of pleased to find I'd achieved one of my slowest freefall speeds, with a sustained rate in the 30s. Sort of pleased, because whilst this is a best for me, slow vertical speeds are better suited for skydiving from planes with appropriate deployment altitudes, whereas on a BASE jump some vertical speed should be sacrificed for horizontal speed. Anyway, see the attached image CraigMBOct2003_3.jpg for the graph from this jump. Although this ProTrack was head-mounted, I'm fairly confident in data as I didn't move my head at all during the flight and this can be seen in the video. These graphs are also available on my online graphing website. However, I'm having some DNS and connection problems with the box so you may not be able to access them reliably: Graph 2 Graph 3 Graphs 1, 2 and 3 overlayed I've also uploaded some video of these flights. My first flight was my best with me reaching the landing area and opening above it at a reasonable altitude, but typically, it wasn't filmed from above and my camera was zoomed in. The second jump is not bad, but the flight seems to stall towards the end, just short of the landing area. I've consulted with a very experienced wingsuit BASE jumper who thinks it could be down to fatigue. Although I can't say I felt tired, it would figure, but also I feel the approaching ground has a sub-concious physcological effect on my flying! The third jump is interesting because you get the perspective of two other jumpers, one without a wingsuit (and front-looping too) and UncleCharlie with. We are both jumping Skyflyers, but I have a lot more experience on mine. What you can't see from the video is that I sink out on the other wingsuit quite early but I make that up as well as overtake by the end, before we both stall again! Anyway, this has been quite a long post. In summary I just want to reiterate, if you don't want your ProTrack to stop recording because it thinks you've deployed on a wingsuit BASE jump, first set the exit altitude using the SPC mode, and then set the unit to SLO mode after it has adjusted to the new altitude. I've contacted Steffen at L&B who doesn't think that setting both the modes had been tested before but believes that what I've seen is "reproducible because the SPC feature just offsets the height and SLO just changes some trigger parameters". Cool! Craig Not a BMCI! :-PSkydiving Fatalities - Cease not to learn 'til thou cease to live Quote Share this post Link to post Share on other sites
DaMan 0 #2 October 31, 2003 Great post - thanks for finding the trick!Z-Flock 8 Discotec Rodriguez Too bad weapons grade stupidity doesn't lead to sterility. Quote Share this post Link to post Share on other sites
leroydb 0 #3 October 31, 2003 What is it that your doing at the end of the flight? Are you turing around? If so, is that to avoid the other side? I don't know this site so please inform... thnaks Le RoyLeroy ..I knew I was an unwanted baby when I saw my bath toys were a toaster and a radio... Quote Share this post Link to post Share on other sites
unclecharlie109 0 #4 October 31, 2003 Just to clarify, the video shows Unclecharlie slowing down to let Craig catch up. Honest Respect to Craig for making the landing area. Does anybody else have experience with "end of flight stalling" ? It seems strange that it affected all 3 wingsuit flyers (2 skyflyer, 1 crossbow) towards the end of the flight on nearly every jump. My initial thought was that it was wind or turbulence at low altitude. (?) Possible explanations: - fatigue, body position goes to sh*t after 30+secs - fear(!) as you get closer to the ground body position goes to sh*t - stalling the suit out, after using the "momentum" of the exit to get flying we sub-consciously trim the suit back gradually throughout the flight until we stall, after which it is hard to get flying again. Any other ideas? Inreasing air density ? Long flights! jb Quote Share this post Link to post Share on other sites
TomAiello 25 #5 October 31, 2003 QuoteMy initial thought was that it was wind or turbulence at low altitude. (?) Why did you discard that idea? When I've been at that site, I've noticed a substantial difference in winds as you cross out of the "bowl" (i.e. past the buttress/ridge on the jumpers left, and over the hump before the landing area). Did the non-suited jumper on your load notice any difference in wind when he approached under canopy?-- Tom Aiello [email protected] SnakeRiverBASE.com Quote Share this post Link to post Share on other sites
ManBird 0 #6 October 31, 2003 Congtratulations, Craig! That's awesome. I still haven't seen the videos, but it's apparent that you had some amazing flights. Thanks for the ProTrack experimentation. I think I'll eventually chuck myself off a rock in a wingsuit, and that's a pretty valuable tip you figured out there. QuoteDoes anybody else have experience with "end of flight stalling"?Yes. You have some excellent theories on why that happens. One more is the possibility that a leg wing deflection is happening as you go for, or think about going for, the pull. When flying hard, making the angle of your d-arch more acute can result in a good deflection, like flaring on a canopy, that can put you below your stall speed... essentially stalling your body (which is, of course, followed by a drop). This was something that I've tried on a number of flights. Deflecting the leg wing and holding it down hard for several seconds can get me sub 30, but I drop out after that and up in the 60s, then have to slow back down to my normal fall rate. I think everyone has a certain "stall speed". Go below that, and you stall. Stay right on the verge of that, and you can maintain a really low fall rate. Stay just above it and drive forwards, and you can get a very powerful flight and gride latio. I mean glide ratio."¯"`-._.-¯) ManBird (¯-._.-´"¯" Click Quote Share this post Link to post Share on other sites
robibird 2 #7 October 31, 2003 hi, I know Italy place very well. Believe my guys. The reason of having the stall problem on very end of the flight is mostly psychological. As you coming to the landing area ( especially on the first few flights ) you quit to fly even though you think that you still fly. In your head thoughts like '' just few more seconds and I am there'' are rolling. When you get over or close to landing you ( mostly) stop working on flights. Once you build up confidence on good exit, consistency of flight and flight speed just aim for new goal - go over the creek or make big ''S'' or whatever fly over, under beside the canopy. In case if stall appear earlier in flight, than the problem could be the flight technique. I saw the Craig flight and all I can say is - Super nice !!! In terms of weather.. Mostly the wind coming from North or South and effects the fight so that push your body sidways, with short periods of turbolence that is all RobibirdRobert Pecnik [email protected] www.phoenix-fly.com Quote Share this post Link to post Share on other sites
