bgrozev

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Posts posted by bgrozev

  3. Annabellacb



    2. Your home DZ has terrible weather that weekend, but you want to jump. What is the main deciding factor outside of better weather that will make you travel to a different DZ?
    (i.e. RV hookups / boogies / A license min w/rental gear / indoor packing floor with carpet)



    I estimate the number of jumps I expect I can make at different locations, and weigh it against the travel time and price. So I find myself checking the weather forecast for the 3 potential locations in my area for a specific period of time (e.g. Saturday through Monday). It would be nice if I could have all that in one place.

    Having a list of events (including closed days) would also be useful. And also accommodation options.

  4. Skydivingmanda

    Hi everyone! I'm new here so bare with me if this isn't in the right forum :)

    I'm looking to see how many people have had shoulder injuries that resulted in surgery and that were able to jump again .
    Unfortunately during my last free fall my shoulder dislocated ( first time it ever happened ) . Between that force, the brutal chute opening and then trying to place it back ( I managed 3 times but it kept popping back out ) , it did some considerable damage .

    I know the recovery is long... I'm still wearing the brace until tomorrow. Surgery was for a bankart and slap repair. No sports until may ... I plan on getting a shoulder sleeve and giving it a try in the wind tunnel first and probably another tandem jump before ever jumping alone again...if any issues occur at these points then I obviously won't do it next summer..

    But I just wanted to hear your stories...your experiences and even your opinions :)

    Thank you people !



    Six years ago (before I started skydiving) I dislocated my left shoulder multiple times, and finally had the Bankart Repair operation. The recovery after the operation was long, but since then I haven't had any issues apart for some minor reduction in my range of motion.

    When I started skydiving and flying in the tunnel I was worried and wore a sleeve. But I did not feel any discomfort or instability, and the sleeve was cumbersome so I stopped using it.

  5. Hi and welcome!

    chasitie

    I was going to try to get as much advice as i can.
    I will be probably going to Spaceland Dallas to get my license.
    What are some things i should focus more on? I'm female and i've heard that women have a hard time landing.. is this true?



    It is unfortunate that you have heard this myth before you've even started. I'm afraid I might oversimplify a complex question here, but I think the short answer is: it is a myth, but many people believe it. I recommend the following video on the topic:
    https://www.youtube.com/watch?v=8INJxZEo4Ww


    Spaceland Dallas is a really really nice place (I've only been there a couple of times). As for advice: talk to your instructors. Many people will be happy to give you advice, but it will not always be good or appropriate for you, and in the beginning you may not be able to tell the difference. When in doubt ask your instructors.


    Welcome again, and I hope you enjoy the sport!

  6. jakee

    ***However, I would like to stay on topic of this specific denial case, but that's a short rope on a long rappel in SC.


    I'm a flat earther denier. I can't believe any of them are for real.

    I was also skeptical of their existence, but I found evidence.

    Someone I know announced a $100CAD award if someone could show him a "non-stop commercial flight from Australia to South America", implying that if such flights don't exist this supports the idea of a flat Earth (I have no idea how that is supposed to work, but that was the claim). Anyway, after 1 minute of googling and 5 days of arguing over whether flightview.com is a fake website or not, I did get my money (and I promptly donated it to the Planetary Society).

    I find this convincing evidence that the person is for real.

    Also, that person happens to be a skydiver. I myself would be uneasy on a plane with him since I think he is delusional. I'm curious what others think: would you jump with someone who shows such signs of delusions in online posts?

  7. Here are my observations from flying a demo X-Fire 124 for two weekends. I don't have much experience flying different canopies, so instead of giving general characteristics, I'll stick to comparing it to my current canopy, a Crossfire2 129. I am just getting into swooping, and that's what I was mainly evaluating it for. This seems to be a common situation for people, so I hope this comparison will be of some use.

    I have an exit weight of 195lbs and the wing-loadings of the cf2 and xf are similar: ~1.51 and ~1.57lbs/sqft respectively. I only made 19 jumps on the X-Fire.

    The openings were quite different from other canopies I've flown (crossfire2, safire2s, sabre2). For the first few jumps I was opening at 10kft (and density altitude of ~14kft), at terminal, and they were a little sharp (FlySight data shows peaks of about 3g, but I am not sure it can be trusted).
    Not uncomfortably sharp, but close. I started to split roll the nose, and that helped a lot. If all openings are like this I would be happy, but I am slightly worried that any outliers (say, 50% faster) will be painful.

    Out of 19 openings, 16 were head-on (within, say, 30˚), one did a 90˚ turn, one did a 360˚ turn, and one did a 360˚ with line twists. The last one has two and a half twists, and it did not dive. That's not much data, but it looks good to me. I think my cf2 has a similar rate of >180˚ turns, and body
    position could be part of the reason.

    The brakes are stowed very shallowly, so popping one toggle doesn't have much of an effect. This is also apparent from the FlySight descent rate data: 12-13mph with brakes stowed, and 13-14mph with brakes unstowed.
    Compare with 7-8mph with brakes stowed and 12-13mph with brakes unstowed on my cf2.

    The canopy is overall more responsive to input than my
    cf2. For toggles and rears the difference is small, but for harness and front risers it is significant. The range of the toggles (from start of tail deflection to stall) is shorter, and they are heavier. Similarly, it stalls on rears with less input.
    I noticed some over-steer for front riser and harness turns, but not much (the cf2 doesn't over-steer at all, as far as I can tell). The toggles are a little bit twitchier, I needed to pay some attention to flare symmetrically.

    The front risers are heavier than the cf2. Once it enters a dive it is much easier to keep it diving by maintaining harness input. I can keep it in a turn indefinitely, while on my cf2 I can not even get a consistent 270 because it starts to recover unless I get it just right. However, once the input is released it seems to recover in a way similar to the cf2.

    With enough speed the cf2 recovers to flying completely level. The xf seems to take longer to recover, but at least on one occasion I see it go to a descent rate of just 3mph, and I suspect that with more speed it might go level too. I wish I had more time to test, as that was the part I was most interested in. In short, the recovery arc seems longer, but similar to that of the cf2.

    In a 90˚ turn, executed in a similar way I lose 380ft on my cf2 and ~450-480ft on the xf. But it's hard to compare because I didn't have time to make my turns consistent enough.

    It feels like there is more power in the flare than the cf2.

    The glide, thankfully, is nothing like a katana. It is perhaps a little steeper in full flight than my cf2, but not by much.

    It felt stable and steerable in deep brakes.

    All in all, I was happy with the canopy and I definitely like it better than my cf2 for my use (starting to swoop). I wish I could also compare it to the Crossfire3 and the Tesla.

  8. DirtyChai

    ***
    a burned copy of the Quran that was stuffed with bacon was left chained to a fence near a Sacramento mosque.



    It still probably didn't have as much an impact as the provocative works of secular liberal atheists at Charlie Hebdo. Who's to say that this wasn't the work of like-minded individuals?

    There's a huge difference between publishing a magazine for people to read if they so choose, and threatening people by leaving hateful signs on their property. Making fun of people on TV is OK, mailing death threats to them is NOT OK -- no matter how you choose to measure the "impact".

  9. mxk

    ***For a wrist mounted visual altimeter... I can turn it on in freefall and/or under canopy.



    No you can't. It needs to measure the pressure at the ground in order to calculate your altitude.


    Absolutely. Completely wrong arm-chair reasoning on my end. Thank you for pointing it out.

    Quote


    bgrozev

    I do have an audible (Quattro) which doesn't need to be turned on manually



    It does if you don't want to waste batteries. From the manual:

    ***NOTE: To save battery power, the screen display will switch OFF after 14 hours. However, the unit is still ready to jump.



    You should be turning your Quattro off at the end of the day and turning it back on before jumping. You're risking it being in jump mode with an incorrect reference pressure (if a front comes through during the night, for example) or being completely dead because the battery ran out. It's a good habit to turn all your digital gear on at the start of the day, check battery status, and let it calibrate for the current atmospheric conditions.

    That's also a good point. Thank you.

    Apologies everyone for drifting the topic. At least I did get some education out of it.

  10. Deimian

    ***
    You can't just ignore some of the words in the sentence:
    "creating a new class of ultra high performance, non-crossbraced wings"

    I have no idea if this is true or not, but the semantics are clearly different than "creating a new class of ultra high performance wings".



    Crossbracing is a construction technique to have a more rigid and efficient wing, while using fewer lines to minimize drag. That's all it is. I am not ignoring words. If they claim to have made a "ultra high performance wing"

    But they don't. They wrote "creating a new class of ultra high performance, non-crossbraced wings". You removed a word from the middle of the sentence...

    Quote


    I agree though that what they meant is *probably* "a high performance wing one notch below crossbraced wings".



    I don't think this is what they meant. As you point out this interpretation doesn't make much sense because "crossbraced" refers to the way a canopy is constructed, and not its performance.

    I think the intended meaning is "a wing which has performance near the top of its class, and it's class is that of non-crossbraced wings", and I also think that's the most natural interpretation of the text they used.

    Similarly "an ultra high performance human-powered bike" is a bicycle with high performance when compared to other bicycles, it's not a bicycle which is faster than a Yamaha.

  11. hardhatpat

    You have to turn the viso on...



    What does that have to do with this discussion? For a wrist mounted visual altimeter (which we are not discussing) I don't really care because a) I'm less likely to forget to turn it on, b) I will notice it is not working when I look at it, and c) I can turn it on in freefall and/or under canopy.

    I do have an audible (Quattro) which doesn't need to be turned on manually and I consider this an advantage. I simply provide this as feedback to the manufacturers.

  12. Deimian

    ***If you could find a 119 x-fire, you'd enjoy going to it from a sabre2 120. Sabre2 135 to crossfire2 119 was good and bad for me. I liked the rears, but it was trimmed too flat, coming from the sabre2. The recovery arc was dramatically shorter than the sabre2.



    Really? That's interesting. Most people comment that the recovery arc of Sabre 2 and Crossfire 2 is very similar. I flew a couple of times a Crossfire 2 and I had the similar feeling, but I didn't do any exhaustive testing.

    CloudCompanion

    The X-fire is my first wing that gives me everything I want. It's not intimidating, but should be respected.



    Have you flown a Katana? If so, how would you compare both?

    CloudCompanion

    To whoever said "how can it be a transitional canopy if its in its own class" or however they worded it, I believe they were aiming to make a stepping stone to cross braced wings. I'll let you know when I get on a cross braced.



    I made that comment. But my wording was more like "how can it be a transitional canopy if it is creating a new class of ultra high performance wings". My point was about being ultra high performance. An ultra high performance stepping stone doesn't make much sense in my opinion. Maybe it is simply a marketing gimmick that turned out to be too bold?

    You can't just ignore some of the words in the sentence:
    "creating a new class of ultra high performance, non-crossbraced wings"

    I have no idea if this is true or not, but the semantics are clearly different than "creating a new class of ultra high performance wings".

  13. aonsquared

    BigL, you use it like an AAD - you turn it on at the start of the jumping day and it will automatically turn off after 16 hours. No need to do anything else except plug it in to change altitudes or charge the battery.



    Some feedback: having to turn it on manually is a significant disadvantage for me. I was considering getting one for my second helmet, but if I have to remember turn it on I might as well move the one that I have between helmets.

  14. RonD1120

    When I learned of this hoax on the radio yesterday I thought it was acutely hilarious. I decided to share it with SC for some relief from the misery of President Trump's election.



    And for some reason I thought you were trying to make a subtle point.

    RonD1120


    I do find it interesting that the academic journal did not recognize it for its absurdity on the first review. They asked for more examples, reviewed it again and then published it.

    One of the main sources the authors cited is:

    http://www.elsewhere.org/pomo/

    This website will provide a different page each time it is reloaded.

    It makes me ponder the question, are these academics the people that are teaching our children?



    It is academics who wrote the hoax article, academics who point out the problem with predatory journals, academics who analyze the peer review process and work to improve it, academics who go after academics when they act unethically. And the community as a whole accepts this as a problem. No one argues, for example, that publishers should continue this practice because it helps young scientist get publications and advance their careers.

    Many religious communities on the other hand seem quite happy to make excuses for all kinds of immoral and unethical acts, and protect people doing them, as long as it agrees with their agenda.

  15. wolfriverjoe

    ***I knew it!

    "YouTuber D Marble flew from North Carolina to Seattle to see if the pilot would dip the nose of the plane to 'compensate for curvature'".



    What an idiot. 200 miles of travel is approximately 130 feet. Well short of the claimed "five miles."



    No, the figure of 5 miles is correct (it is about 8 inches per mile, but it doesn't increase linearly). Expecting that the level would change in this way is of course ridiculously silly.

  16. yoink

    Link still works for me.


    But still,

    Quote


    The Skeptics Society is a nonprofit, member-supported organization devoted to promoting scientific skepticism and resisting the spread of pseudoscience, superstition, and irrational beliefs



    Emphasis mine.

    But publishes a 'paper' written by an algorithm that ties together random buzzwords....

    http://www.acsh.org/news/2017/05/19/hoax-science-paper-says-penis-social-construct-worsens-climate-change-11302

    ***
    A new team of hoaxers has struck again, this time in the journal Cogent Social Science. Even though the authors have already admitted to their hoax in the magazine Skeptic, the journal apparently is unaware. The paper is, for the time being, still available



    Cogent Social Science is the journal which published the hoax article, Skeptic magazine is where the authors detail their hoax:
    http://www.skeptic.com/reading_room/conceptual-penis-social-contruct-sokal-style-hoax-on-gender-studies/

  17. RonD1120

    This academic paper has dealt with the current problem as, IMO, manifested in the MSM.

    Quote

    We conclude that penises are not best understood as the male sexual organ, or as a male reproductive organ, but instead as an enacted social construct that is both damaging and problematic for society and future generations. The conceptual penis presents significant problems for gender identity and reproductive identity within social and family dynamics, is exclusionary to disenfranchised communities based upon gender or reproductive identity, is an enduring source of abuse for women and other gender-marginalized groups and individuals, is the universal performative source of rape, and is the conceptual driver behind much of climate change.
    An explicit isomorphic relationship exists between the conceptual penis and the most problematic themes in toxic masculinity, and that relationship is mediated by the machismo braggadocio aspect of male hypermasculine thought and performance. A change in our discourses in science, technology, policy, economics, society, and various communities is needed to protect marginalized groups, promote the advancement of women, trans, and gender-queer individuals (including non-gendered and gender-skeptical people), and to remedy environmental impacts that follow from climate change driven by capitalist and neocapitalist overreliance on hypermasculine themes and exploitative utilization of fossil fuels.




    http://www.skeptic.com/downloads/conceptual-penis/23311886.2017.1330439.pdf



    I have no idea what point you are trying to make, but it appears that the published has withdrawn the article:
    https://www.cogentoa.com/article/10.1080/23311886.2017.1330439

    Quote

    This article has been withdrawn and the authors have been notified. We are currently carefully examining the process that led to its publication and will provide more detail on this in the coming days. Please check back here for more information.

  19. justme12001

    I had not heard of this canopy before this thread, so I looked it up.

    From the PD Horizon page:
    Best of all, the Horizon gives you the ability to upsize as many as two full sizes compared to a non-crossbraced ZP canopy main, meaning you can fit a larger canopy in your existing rig for wingsuit jumps. No need for a new container!

    So I don't think they are saying you NEED to upsize two sizes to jump it. I think what they are saying, is since it is low bulk, you CAN upsize two sizes and still use the same rig you are using with your "normal" canopy.

    Watching the promo video, the canopy seems to fly and land well. The pilots were using a two stage flare to land, instead of the one stage you normally see with F-111 canopies.



    The relevant part of referenced document:

    Quote

    [w]e recommend that you have at least 50 jumps o
    n a canopy (landing accurately and comfortably on your feet) that is approximately two (2) sizes SMALLER than the Horizon you plan to use for wingsuiting.

  21. gunsmokex

    I wanted to say that it feels damn good to have stand-up landings all day long. I watched some of my friends struggle with no wind landings the other day tumbling in on some pretty nasty landings, I'm glad they are ok but they will be a little sore I'm sure.

    It reminds of why I didn't downsize yet. A couple of weeks ago I jumped at Mile Hi in a LOT higher density altitude than I am used to 6000-7000 and also did one jump at a small DZ in the same density altitude into a tighter landing area. Crosswind, no wind, downwind I've had nothing but standup landings and they aren't just standups they are the no, one or two step toe tappers.

    That being said I'm at a hell of a dilemma. Its time for new gear and I'm going to have to decide whether to stick with my 1:1 170 or move it down to a 150. I absolutely love my old PISA Hornet and the old bird has done me well. I have nothing to say about the Hornet, I've gotten the pack jobs to super soft sniveling openings get back from long spots and love the flare on her.

    Anyways someone give me a reason on why I should downsize? I don't really see the point in it I guess.



    You don't see the point of downsizing and you are happy with your current canopy -- where is the dilemma?

  22. I wouldn't carry an additional device just because of this. I already have my phone with me when I jump, and so I am left with two problems:
    1. How to quickly and easily provide my location to the DZ if I land off (I believe Burble already solves this).
    2. How to do the same if I am incapacitated.

    I don't think there is currently a solution for the second problem (correct me if I'm wrong), but I think it is solvable. Here is one suggestion: the event of "landing" can probably be detected based on GPS. If the landing is found to be outside some defined landing area, alert the user and schedule an alarm. If the user does not respond and stop the alarm in, say, 30 seconds, notify the DZ (or someone else) with the location.

  24. https://www.youtube.com/watch?v=fst6brFx0xc

    If I'd seen this interview first, I would have thought this is the new Ali G "go-pro hero" character.


    "What do you say to people who want to follow in your footsteps."
    "Go for it, I'll teach you."

    I guess he's the top pro in his niche. He has, like, more than 7 illegal pool jumps on youtube now, and, like, you know, almost 90% success rate.

  25. I haven't forgotten to turn my on yet (unless I forgot and then failed to even notice, which I doubt ever happened). I make a conscious effort to slow down, actually take a breath, and do a no-hassles check every time before I put my rig on. It only takes 20-30 second, which is not substantial even if I'm in a hurry. And when I am in a hurry, the very fact that I have to change speeds helps me to notice that I'm in a hurry and take a mental note.

    The way I think of it: this saves my life with probability epsilon, and saves me needless worrying on the way up with probability 1-epsilon.