yuri_base

HUD does not need to be complex, it can be just a semitransparent mirror or two mirrors reflecting the smartwatch's screen which is mounted on the helmet out of the way. There are cheap products ($3-10) for smartphones that do the same: [inline HUD1.jpg] [inline HUD2.jpg] For a smartwatch with 1.4" screen, the whole thing can be quite compact. Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

I use the 99 cents grippy gloves from Home Depot. They're thin, so maybe not enough for real winter, but enough for the temperatures when your hands get pain from cold. Can't find exact model, but similar to this: https://www.homedepot.com/p/2XL-Black-NiteGrip-6001-2XL/302952136 They provide excellent grip and precise feel-through. Imho, Neumann's are way overhyped. Way overpriced ($45 LOL); not warm for real winter, either; weak, tear easily; not enough precision feel to make things like collapsing slider easy. I recommend to everyone when needing peripheral gear, to look elsewhere, not skydiving shops. Gloves, helmets, goggles, even altimeters - there are excellent alternatives available that work well and are not outrageously priced. Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

Buyer beware: Garmin Fenix 3 does not update altitude in freefall fast enough, some skydivers reported that it stops updating after exiting the aircraft and resumes only after opening, some see 1000ft delay: https://www.youtube.com/watch?v=KacXA8OJ4fo This is a perfect illustration of my point that hardware is "game over", meaning that it doesn't make sense anymore to make specialized hardware to measure altitude - "generic", affordable hardware (like Moto 360 Sport, $50) already exists (and will only get better with time) with excellent barometric sensors, the game is software. It's software that can make an expensive hardware a piece of junk; or can make an inexpensive hardware shine. And with Android/Wear, anyone can start writing their own altimeter app. Let's Make Altimeters Great Again! Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

Here's the diagram I promised. I didn't find the pressure distribution around a cone, but by analogy with the pressure distribution on the bottom surface of an airfoil - [inline AirfoilPressureDistribution.gif] - pressure is nearly perpendicular to the surface of the cocoon, so it tries to compress the cocoon, not to "skin" it. Fresh ZP is happy to unwrap itself as it's so slippery and springy, but used ZP's friction can keep the cocoon closed for an extra fraction of a second and cause the slider to slide down the lines as it encounters no resistance from the wind - it's inside the "cabin" of the cocoon. With wingsuit, due to sagging, the air mostly hits the bottom of the cocoon which is a smooth surface and it's just happy to stay closed and trailing behind. [inline MechanismOfCocoonHesitation.jpg] Anyway, I feel I said everything I wanted to say, tested the ground 5 years after first sharing this (after about 4 years of testing it), and it's still infertile. Oh well, not the first time, not the last. I'll revisit the topic in a few years to see if it's a good time to plant the seed. Bye bye now! Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

>>> BASE pack jobs. (Neither of which, of course, having "slow comfortable deployment" as a goal.)

https://www.youtube.com/watch?v=Bg8O5-6fDz0 This is a tracking jump pulling from full flight, and since I'm heavy (260lbs out the door), the speed is "superterminal" for sure, perhaps, ~140-150mph? Not a problem for Exposed Slider method. The opening is not "falling into pillows", but is not hard either. Yes, I've got an offheading 90 degrees, but taking into account that I rarely jump my tracksuit (almost 100% - wingsuit), it's not too shabby. **Insults removed** Try it in 2-3 jumps moving the mouth of the cocoon down 1 inch at a time. When the logic of presenting the slider to relative wind as #1 stage in the openings sequence (after D-bag opens) becomes obvious and tried, stand in the middle of the hangar and loudly proclaim: "Guys, I just had my FIRST properly staged opening! Beeeeeeeeeeeeerrrrrrrr!!!" Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

These are just weak excuses, once it's admitted that it's "officially" (from PD) OK to just "lay" the mouth on top of the grommets (there's no tension, no resistance there), or make them even barely visible through the hole, one might as well just "go big" and expose them fully. The way it's done in my photo actually keeps the bulk of the slider under some tension of the "neck", there's no tension whatsoever in the PD Horizon photo. It's fascinating to watch how resistance to any deviation from habits and dogmas works. "This is PD, this is OK, but not even an inch lower! Once even 1 millimeter of the shiny grommets becomes visible, bad things will happen catastrophically!" Hard to believe, but it proves to be true - very experienced jumpers with many thousands of jumps are scared to do 2-3 jumps with gradually lowering the cocoon. And it's not about "Soft and gentle", it's about priorities, it's about doing things right, it's about staging the opening properly. And to stage it properly, slider must be numero uno thing that is presented to the wind. Not the cocoon... slider. Period! The openings become more immediate, without wasting altitude to "Soft and gentle". How many times we've read in fatality reports, that "after cutaway, the reserve was activated but didn't have enough altitude to fully inflate"? (extra 100-200ft would make a huge difference.) That's because of wasting altitude to "falling into pillows", "Soft and gentle". We're not jellyfish, we don't need to fall into pillows, we can take an opening that starts immediately, but is not hard by any measure. Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

>>> That looks similar to what PD recommends for packing the Horizon. They state to leave a small mouth open at the tip of the cocoon.

>>> Why dont you just email John LeBlanc and ask him what he thinks?

Haha, this is awesome, thanks! [inline ReserveWithExposedSlider.jpg] Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

>>> https://www.youtube.com/watch?v=cVAoiLl2B6M

How does a non-collapsible PC keep the lines straight? Both a collapsible and non-collapsible PC will be fully inflated until the canopy is completely out of the bag. The lines in your video dident look any more 'all over the place' any more than a standard belly jump. Slowing down the video, the lines were most chaotic right after a stow released them, suggesting a semi-stowless bag would be of greater benefit to prevent that. Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

https://www.youtube.com/watch?v=hVJjN-O6EG0 I found an example at 120fps, but not sure if Youtube retains 120 or downconverts it to 60fps. Anyway, try setting 720p60 in Quality and 0.25 in Speed. If you view frame by frame, you'll see that the slider got a bit "confused" in the first moments probably because it was not quartered well, it took a few moments to quarter itself. Presenting more videos like this won't show anything new, the openings become 1:1, carbon copy of each other. Immediate and on heading. Boring, no variability. Those who crave the excitement of "panoramic linetwists" and cutaways, can always hide the slider under the cocoon. For wingsuiters, I recommend dropping all this collapsing PC BS and getting a non-collapsing PC. With big wingsuits (this is V-4 in the video, that's not very big) the burble is massive, even when pulling from full flight. The burble causes the lines go all over the place. Non-collapsible PC will keep the lines straight throughout the deployment. My "burden of proof" is officially furnished. It's now up to you, ma chickenz, to multiply and lay more eggs! Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

I posted both before and after videos (they're small to fit under 1MB limit, but enough to show the gist). They are 30fps, can be examined frame by frame. Doing more fps won't produce more evidence, just more of fabric flapping in the wind. But everyone is welcome to, it won't be coming from me anymore! Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

>>> Why do you recommend this method for WS jumps but not standard terminal jumps? If the cone hiding the slider from the wind is the issue, the cone is still wrapped around the slider on belly jumps too you know.

>>> I think I know what equation you're going for but you're leaving out just every real world concept and confusing statics, dynamics and fluid dynamics. And yes that's what my degree is in. What you're trying to say is that there's a relationship between friction, force and the angle of the fabric against each other. That's not something that can be modeled by back of the napkin math or really any mathematical equation as it applies to fabric at those wind speeds. Please continue with your experiments in the air and we'll be happy to learn from the results.

>>> He's also missing a lot of the forces involved, like acceleration during deployment. Indeed he explicitly ignores it - "Slider in this case is like a pilot in the cabin" - as if there are no acceleration forces on the slider. > As a side note, what many people experience during their packing careers goes something like this: They try to learn to pack. Their new ZP goes everywhere. They get hard, inconsistent, off heading openings. Someone tells them to try psycho packing. They try it for 30 pack jobs or so. ZP goes everywhere. They get hard, inconsistent, off heading openings. Someone tells them to try putting the top of the canopy in the bag first before the S-fold. They try it for 30 pack jobs or so. ZP goes everywhere. They get hard, inconsistent, off heading openings. Someone tells them to use a hook. They try it for 30 pack jobs or so. ZP goes everywhere. They get hard, inconsistent, off heading openings. Someone tells them to turn sideways while they are packing. They try it for 30 pack jobs or so. ZP goes everywhere. They get hard, inconsistent, off heading openings. Someone tells them to pack on concrete instead of grass. They try it for 30 pack jobs or so. ZP goes everywhere. Their openings start to get better! Their conclusion - packing on grass causes hard openings. They post on S+T to tell everyone the wonderful news, but lament that until someone like John LeBlanc tells everyone this obvious truth, people will still suffer hard openings. What has really happened, of course, is they just did 150 pack jobs and got to be better packers. But packing is so complex, and so hard to learn - and improvement comes so slowly - that they chalk the improvement up to the last thing they tried. I have a feeling the same thing is going on here. But everyone has to learn that for themselves.

Further argumentation of the discovered mechanism of hard openings due to cocoon hesitation and of proper use of slider. The packed canopy cocoon is like a cone, with some angle at the apex. The wind force tries to push the center cell tail surface forming the cocoon "up" this slope. The aerodynamic force acting on the angled surface of the cocoon is at some angle to the surface, and due to relatively high lift-to-drag ratio of the angled surface, this angle is actually close to perpendicular to the surface. (I'll draw a force diagram later.) Let's call this angle between perpendicular to the surface and aerodynamic force alpha. We know from basic physics that for an object to slide on an inclined surface, tangent of the angle to horizon must be greater than the coefficient of friction k: tan(alpha) > k So for the tail to start sliding off the rest of the canopy, while experiencing friction against it, k must be below certain value as per formula above (read from right to left). If for fresh ZP k is less than this value, it will slide off easily; if ZP is no longer fresh after few hundred jumps, k might exceed this value and then cocoon hesitations will start to happen. This is the physical mechanism for cocoon hesitations (CH). Now, let's consider what happens during the CH. When the cone stays closed for some extra tenths of a second (on WS jumps sometimes even one or two seconds, due to slower speed and angled deployment), the slider experiences zero force from the air, and its heavy grommets start sliding down under the cover of the cone. The apex of the cone itself cannot stop this, since it simply moves with the grommets pulled by gravity. Slider in this case is like a pilot in the cabin: there's no wind to push him against the seat, and if the plane is falling straight down nose first, the pilot will fall out of the seat forward on the dashboard. Slider moved a few inches down the lines - boom, a hard opening. If slider is exposed, it's like a pilot with no cabin - he's pushed by the wind into the seat. Same with slider - it's pushed against the stops with significant force - probably, ~100lbs. It's not going anywhere and starts doing its primary function - reefing - immediately. When canopy starts inflating, it resists the expansion and slows down the opening. This is the proper opening sequence - slider is inflated immediately and starts working. This is the proper way of packing. Slider MUST be exposed, not hidden. Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

>>> This technique might work for the slower environments of Wingsuiting but it is not recommended to do it in a terminal environment.

The blue thing looks like a retractable conical vane, that automatically extends on exit and retracts into the helmet before deployment. That would be totally magical. Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

>>> Also, even in non-steady state, AGR is actually ~1% (depends on Vy) higher than L/D, because of increasing density going down

That. is. so. cool! Kudos! And this is just the beginning... I'm not kidding when saying that WSE are like Pandora box! Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

An example of Cocoon Hesitation was posted above; here is an example of an opening (same canopy, Spectre 190) with the Exposed Slider method. The opening is more immediate, with stronger initial jolt on the shoulders due to towing the inflated slider in the first moments, but the openings are comfortable, just not wasteful of altitude. And I've had ~400 of such openings like this one, 1:1, virtually exact replica. Openings become very consistent, and with very good heading performance (thanks to inflated slider anchoring the heading). It feels like it even 'corrects' your body position! (because the inflated slider is hard to turn, it turns your body is you drop one shoulder; with cocoon-cigar, dropped shoulder spins the cigar very easily, besides its own dance) And... ZERO line twists. (before, linetwists were like 1 in 3-4 jumps, that would be >100 linetwisted openings out of 400 jumps!) I'm no longer jumping my skydiving canopy, so if anyone asks to take a video of packing or opening, I can't do this. If nobody jumps this pack job, the idea will be buried, but I'll remind again in 5 years, since in skydiving world any fresh idea takes decades to pick up. Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio OpeningWithSliderExposed.m4v

>>> Anyway, on my first Swift 3 jump I had a hard opening which lead to massive line twists putting my canopy into a spin with me trying to fix it on my back. It opens off heading 50%+ of the time on WS jumps and when it does open in serious twists it spins up.

>>> With the chaos of openings your sample size it not enough to prove anything.