Skwrl 56 #1 February 1, 2012 Hi all, A couple of my fellow wingsuiters and I are preparing a talk on avoiding tail strikes for our upcoming Safety Day. I am wondering if anyone has prepared such a presentation before, and if they'd care to share it. We plan on creating our own content for this presentation, but insights as to how others have talked about it in the past would be useful. We'll make our presentation available on dz.com when we have completed it (which should be in advance of Safety Day, obviously). We're not just interested in tail strikes by wingsuiters - we're aware that lots of other, non-wingstuited, jumpers have hit the tail from time to time, so it doesn't need to be wingsuit-specific. Thanks for any help you can share. -JeffSkwrl Productions - Wingsuit Photography Northeast Bird School - Chief Logistics Guy and Video Dork Quote Share this post Link to post Share on other sites
Southern_Man 0 #2 February 1, 2012 There is a resource on tail strikes that Jan Meyer has written. Pretty sure you can find it with a search. Nothing specific to wing suiters if I remember right. http://www.makeithappen.com/spsj/collisio.htm edit: There's the link."What if there were no hypothetical questions?" Quote Share this post Link to post Share on other sites
Para5-0 0 #3 February 2, 2012 I would contact DSE and get his input. Quote Share this post Link to post Share on other sites
fencebuster 7 #4 February 2, 2012 +1Charlie Gittins, 540-327-2208 AFF-I, Sigma TI, IAD-I MEI, CFI-I, Senior Rigger Former DZO, Blue Ridge Skydiving Adventures Quote Share this post Link to post Share on other sites
DSE 3 #5 February 2, 2012 QuoteI would contact DSE and get his input. Jeff is looking for non-wingsuit tailstrike info. I've shared the same doc with him that was shared with you. There was the one at Lodi, and a camera flyer down east (Deland?) that I'm aware of, I'm sure there are more that I'm unaware of. Quote Share this post Link to post Share on other sites
MakeItHappen 15 #6 February 3, 2012 The stuff I have is related to specific incidents and is generally work product done for others (some related to lawsuits). Thus, it cannot be released, except for the article already cited. General trends can be stated. A larger projected surface area perpendicular to the relative air stream will slow your velocity component in the direction of the relative air stream much faster than a smaller projected area perpendicular to the relative air stream. Collisions between an aircraft and jumper occur when the trajectories cross. The trajectories cross when the individual vertical velocity components of each body do not provide sufficient separation during the time that the jumper is supposed to pass under the tail or equivalently when the differential between the horizontal velocity components of each body is such that there is insufficient time for the bodies to separate vertically. In jumper speak, if you present a huge surface area to the relative wind on exit you are more likely to hit the tail. Also with WSs, the lift coefficient of the jumper needs to be assessed, even if the projected area perpendicular to the relative air stream is 'small'. .. Make It Happen Parachute History DiveMaker Quote Share this post Link to post Share on other sites