the.Legend

Interesting. How about replacing the LCD with a monocular then? https://www.aliexpress.com/item/1005001355384065.html

I was watching old video from WS race and noticed that competitors intentionally do a backflip on exit (1:41 on video) What's the reason behind that? Is that because for a second you have head-down dive, so flier gets more initial momentum and also suit inflates faster?

Quick update: battery has been replaced with other, more reliable and I was able to test it today. Long story short - the unit didn't work as well as I'd expected: it was perfectly fine during the climb, showing both ground speed and distance, but during the jump when altitude drops quickly it just stops processing all the readings. Under the canopy it works again, but the moment you do any kind of dive it stops reading again for a second. Well, it wasn't designed for skydiving after all, so nothing to complain about. At least I was able to measure my ground speed under the canopy, so it could be used for some basic canopy piloting drills, but nothing more than that. P.S. Turns out the plane travels in circles roughly 70 km at ~190km/h to climb to a 4k

Just out of curiosity where are you planning to store fuel tanks and what's their capacity? Was this design inspired by Igor Negoda's youtube videos? :)

Yeah, Kharkiv does that. This year's Polish BigWay record was supposed to happen there with An-72 being the delivery boi but then covid happened But as far as I know An-72 is not commercial and actually belongs to military, so usually they take it for special occasions like bigway or sequential camps, while regular-day jumps are from An-28 - beautiful turbofan machine with rear ramp and twin tail :) Prices for food and accommodation in Ukraine are really low compared to Europe or US, ticker price is around 27$ though https://skydive.com.ua/en/index.php

A quick project for tracking basic data during flight. This is a garage project I made out of own curiosity. Not tested in flight yet, if you decide to do it you're doing it at your own risk. There are advanced solutions on the market like Dekunu One or Aon X2 and if you can afford them I encourage you to use professionally made equipment. You'd need: * Car GPS speedometer (I used this one because its shape and size are already almost snag-free: https://www.aliexpress.com/item/4000265066382.html * Powerbank (with least capacity and smallest size possible - in the prototype this one was used: https://www.aliexpress.com/item/32945597181.html ) * 850 mAh battery (ideally 2000 mAh, but unlikely they'll fit inside the case) * Small switch Assembly is pretty straightforward: unsolder USB ports on both GPS and powerbank, solder switch and battery. Additionally I flipped the capacitor (it's under white tape on the first photo) - put it on the opposite site of the board to give some room for powerbank's charger. The device is mounted on a rig using velcro strap with a loop. So far I tested it on the ground on a bike and the speed is pretty accurate - +/- 1 km/h to what smartphone GPS shows Even with 850 mAh battery the device help up for around 8-10 hours (screen constantly on) which is quite impressed actually. Talking about the battery - attentive reader might notice that it got swollen - probably because powerbank's changer is for 2000 mAh, while battery is 850 mAh. That's a critical flaw because swollen battery has high risk of explosion as pressure changes during climb to the altitude. If I ever decide to use it for actual tests, the batteries will be replaced with non-chargeable lithium batteries just like in audibles (powerbank's module would still nicely convert that into a constant 5V supply). Meanwhile I'm doing some more research to find safe chargeable batteries. Now, what this thing can do: * Display current ground speed (both metric and those other, inferior units). Speed alarm can be set at as high as 200 km/h, so I'd assume device can measure at lease that much * Display one of 8 directions ( N/NE/E/SE and so on) - yeah, it's pretty basic, but better than nothing * Display distance covered, accuracy 100m * Display few other stats, but those are useless for WS flying * Oh, yeah, you can change colors Again, this is a garage project. I'm only sharing the fruits of my curiosity and taking no responsibility for what you might do with it.

A piece of useful information I came across which helps in selecting canopy models based on personal proficiency and experience: http://www.parachute.nl/fileadmin/knvvlpa_upload/pdf/BVR_bijlage_B_versie_2017_mei.pdf [Same file attached in case permalink gets changed] [categories explanation attached as well] At glance, it covers all popular models on the market. Big thanks to Holland's association for updating this list every year. N.B. Always remember: such information is provided for educational purposes and does not substitute discussion with your instructor and rigger regarding future canopy choice. Not sure if it was posted on forum this year or not, so please pardon me on that.

Should I say "Thank you for good Safety Day material"

I think that you misunderstood my comments. After all we're talking about some of possible scenarios with smaller probability of occurrence than when other safety system work correctly. As you mentioned, in posts above people already pointed out the most obvious flaws. What I'm mere suggesting is the things I'd pay attention to if I were to design this product. 1) Let's assume that you have two-out for whatever reason. Also let's assume that one of main's line got wrapped around that piece where camera attaches to the plate (blue line in original attachment). Even if you cut away either camera or canopy or both you still have a line with two-sided hook tied to it. Because camera and hook plate are inseparable now. This situation is rather dangerous, don't you agree? 2) Ease of installation is quite a big factor. Imagine that you bought an iPhone and the charger that goes with it actually consists of two wire pieces and every customer must solder them together to make it work. Pretty simple operation if you ask me. But would it be convenient for you as a customer? While it might not be an obstacle for some, it might be a deciding factor for others, so you're loosing customers. Yes, there are many similar products on the market, which foresee drilling holes. And others don't. If I had to choose between this and GrellFAB Front Mount I'd choose the latter because it works right out the box. 3) Ok, I might be exaggerating about head injury by two bolts. 4) As you may already know in skydiving nothing "unlikely" is impossible. In this very thread there was a mentioning of line got caught under grommet. How "unlikely" is that? With these springs I assume the scenario when you cut away the camera, don't cut away main, spring catches the line and while canopy is stalled or simply other lines aren't stretched yet it snags another line. While I agree this is a border-line scenario, its possibility still above zero. I genuinely wish people to design this product and stand out from their competitors.

Apart from what being said above, two more things popped out to my mind: 1) Scenario where you did release the camera, while it snagged the main, you still have pretty good hook between camera and Mount (see attached. Blue line is Main, Red is reserve) 2) Your design assumes drilling holes in helmets. Not only this undermines helmets integrity, it is also very impractical. I had few attempts before I managed to attach camera to be focused _perfectly_ straight. Thankfully, M3 glue base could be easily detached with the help of hairdryer if mistake is made. Drilled holes however are not. And not every skydiver is good with drills either. Oh, and not every helmet has lining detachable. If you rip it off, you have to glue it back somehow, and again, not everyone will have tools for that (hot glue gun for example) three things actually: case of headbang with other skydiver: those screws (even if made of plastic) could somehow damage the skull, or at seriously least increase the risk of loosing consciousness. 200+ lbs of meat'n'bones impacting at even 60 mph is not a joke. IIRC even this year a person lost a limb during high-speed impact with other skydiver. Take all the things into account and good luck with your design ;) P.S. After writing this post found another flaw: springs. I know they are detachable but still they are flying hooks of steel. And regardless of how improbable that might be, once spring catches the lines there's no way for it to be released until you land reach the ground. How improbable? That improbable: https://www.youtube.com/watch?v=0-rltgVgGtM Just replace them with rubber or glue them to the bottom and make short enough not to stick out

One of the worst jumps I ever had: It was season closing celebration day and DZO brought huge soviet Mi-8 copter, so everyone was eager to do something big. Our group was not an exception and somehow we managed to gather 8 people. Most with rather doubtful qualification to do 8-way (that is, only 2 or 3 had between 100 and 200 jumps and only one had few hundreds). We made a girl with circa 35 jumps to be the base (cause base is for noobs, right? Big boys don't go base :D). The flight plan was roughly like this: we get on board, go up and then jump. Should we train exits? What for?! Even student knows how to do that, right? Exit lineup? No need, the ramp is huge! Just stick together, we'll be fine. We were exiting 2-nd, right after 9-way group. Now, Mi-8 doesn't fly as fast as airplanes, so you have to give few extra seconds of separation. With that, you'd give ~15 seconds for 9-way. We gave them 7 at max. Oh, and we didn't have a leader on that jump. Everyone was looking at each other and when someone jumped out first the rest followed him like horde of lemmings. Air time was a total disaster because base was drifting left and right and spinning like a broken Ferris wheel. Maybe one or two managed to dock. We might even had some minor collision, but I don't remember now. Oh, hey! It's time to open! Wait, what are those bright dots coming right onto us? Oh, right! That's the 9-way group My parachute just left the container as I flew past someone's opened canopy with maybe 50 meters between us. Luckily at least landing was without any incidents. Many lessons were learned that day. Since that day I made myself few strict rules for group jumps, so if at least one of them broken I'd better go solo than be a part of suicide squad again.