696GrocuttT

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Posts posted by 696GrocuttT

  1. Posted

    I've written an app that can draw speed / altitude graphs of jumps. I recently got a protrack 2 and I'd like to add support for reading the log files it creates. The snag is I haven't had a chance to jump it yet, and will all the virus problems at the moment, I don't think I'll be able to get to the DZ any time soon. 

    If anyone has some logs from a protrack 2 could send me so I can start adding support to my app, I'd be very grateful. If you plug the protrack into a computer via the micro-usb socket on the side you should see the log files. At least this way I get to do something at least slightly skydiving related while I'm on lockdown.

    Thanks

    Tom

  2. I've created a skydiving app which uses your iPhone to automatically log your jumps. I've recently added some new features that I need help with testing in a Beta version of the app. Unfortunately all of my usual testers have gone into hibernation for the winter, so I'm looking for volunteers who either live somewhere they can still jump without freezing their tail feathers off, or are going on a jumping holiday somewhere nice and warm.

    All I need you to do is use the app to record your jumps and email me the logs at the end of the day so I can check if everything is working ok. It's also helpful if you let me know if you spot anything that's wrong (e.g. an incorrectly reported exit height).

    There are a few other things to bear in mind:
    * For safety I'd recommend you have at least 200 jumps, or as a guide, whatever the criteria are for jumping camera in your country (whichever is greater). If in doubt talk to an instructor. I'm being cautious here: you don't need to touch your phone after take off - just have it stashed safely in a zipped pocket.
    * Your iPhone must be running iOS 9.3 or later.
    * The accuracy of the app is limited on the iPhone SE and the 5s and below. This is because it has to make do with GPS and can't use the altimeter built into newer iPhones.
    * I don't make any money from the app, so I can't pay you for helping to test it, but I will add your name to the Acknowledgements page.
    * The logs I need will include your location, altitude, etc from whenever the app was in "Record" mode. However if you only switch "Record" on when you're at the DZ, I'll only get to see the location of your DZ and where you were flying. The app also makes it easy to choose which days to email me logs for, so it's easy to leave stuff out if you don't want me to see anything.
    * I'm working on adding support for the BadELf family of bluetooth GPS units. This will allow much more accurate data and higher speed sampling. If you have one of these units I'd really appreciate your help testing this feature.
    * I’d love to hear your feedback and any suggestions you have for additional features.

    To take part, you’ll need to install the app through Apple’s official TestFlight system (see https://developer.apple.com/testflight/). If you're interested, just PM me your email address and I’ll send you an invitation.

    Thanks in advance,

    Tom

  3. Quote

    Please post it to here once you find it. I'll add them to ParachuteManuals.com as soon as I can.



    Just got my hands on it. Its too big to post (just under 2.5meg), If anyone wants a copy send me your email address and I'll send it to you.

    Tom

  4. What I can't figure out is why the bulletin isn't easy to find on the paratec web site (I still haven't found it on there site at all). The same goes for the BPA web site.

    I've also just heard from a friend (the same rigger that got me a copy of the paratec bulletin) that a similar bulletin has come out for the PdF containers. Haven't seen anything about this anywhere else, but she was spot of with the paratec mod...

    Tom

  5. After a bit of a wild goose chase I managed to track down an english version. Strangely the BPA's technical officer told me on the phone that he hadn't heard of the bulletin. Yet when I talked to the UK dealer he told me that he'd been sent it by the BPA!!!

    I read the following in the bulletin:-

    Quote


    The relocation of the cutter is ordered by the manufacuter of the Cypres AAD for
    all H/C systems which feature more than 2 flaps covering the pilot chute



    Presumably if Airtec is ordering this it well affect other containers as well as the NEXT, but the only other container I've heard about this mod is the Mirage. Anyone heard of other containers being effected.

    Tom

  6. I've got a paratec NEXT container, and I've heard that there is a service bulletin out to move the cypress cutter (similar to the mirage mod a few years ago). But I can't find any details on it. The only SB I found on the paratec website was about reserve pins from a few years ago.

    I've googled a few times, looked over the BPA website, and a few others but can't find anything. I've also talked to a few friends that remembered seeing something recently but can't find the details

    Has anyone heard about this service bulletin, or know where I can get the details??

  7. Quote


    Right, but Wingloading and manuevers play a role. You can't simply say a VX-46 will cause it to fire and a VX-60 won't. It isn't that simple.



    Well of course WL and manoeuvres play a part. Which is why the WL is given on the www site I posted. I didn't mention the specifics in my post for brevity.

    The jumper was Luigi Cani, and they were trying to get it to fire so they undoubtedly tried several different types of approach.

    Quote


    For example, even after these tests, Airtec could not tell me if my Cypres would fire or not.



    Could not or would not?? You were asking them to put there neck on the line. If you read the label/manual for any bit of skydiving equipment it usually says the manufacturers are not responsible for any loss of life etc. So if they did state that you could not get it to fire on your VX, and it did...

    I doubt you'll find anyone in this industry that would put there neck on the block in such a fashion. Besides the person you spoke to would probably not be able to speak for the company, even if they had legal representation present.

  8. Quote

    They aren't responsible for that. Where they are at fault lies is in how they handled a potential safety hazard.

    They knew about the potential problem, and they knew about it for quite a while. They made no effort to alert the people who needed to know.



    Check out the following page

    http://cypres.cc/Sites/englisch/Skydiving_Small_Canopies.htm

    Basically they are saying publicly that you can get a cypres to fire, but as far as they know you need a VERY extreme canopy (ie VX 46) to do it. There results from the VX 60 didn't cause it to fire.

    So yes they knew there was a problem, and they stated that on there www site. But they didn't think that it would cause a problem for canopy pilots.

    I'm sure they are as surprised and shocked about what as happened as everyone else.

    At the end of the day skydiving is very risky, its not possible to eliminate this risk, but it can be managed. Hell I'm sure there are people out there that jump because of the risk. I don't think we should jump down airtec's throat because of this incident, especially since they have time and time again proved how committed to this sport they are.

  11. Quote


    However, your harness is also "split" in two (with the second half behind you and built into the container), so wouldn't the force be similar at the MLW adjuster as it is at your leg strap buckle?



    I don't think its the same. Again I could be wrong about this but I'm pritty sure there isn't a lot of force that goes through the container itself (and the webbing in it). If there were why would the laterals be designed to go horizontally from the bottor of the container to the MLW.

    Any comments from the riggers out there. I'm sure most if not nearly all of your weight is carried by the MLW, hence the name.

  12. Quote

    Given that the same locking mechanism is used on leg straps (I assume - it looks the same to me), what is the difference here between the stresses on the leg strap webbing relative to that on the adjustable MLW on these rigs



    I could be wrong about this, but I would have thought that the stress on the leg strap hardware is about half that of the MLW adjustment.

    If you think about it the force you put on the leg strap will be divided between the 2 ends of the leg strap that go into the hip ring (if you have one). The hardware is only on one of these.

    I'm not sure how the load on the webbing/hardware affects that wear rate. But I do know that I've seen lots of wear on both adjustable MLW's and leg strap hardware.

  13. Quote

    the new zerox is a next clone!



    The next and the zerox are actually both made at TSE in the UK. Paratec make the canopies in germany but sub-contract the manufacture of the NEXT to TSE.

    If you compare a next/zerox to the tear drop superfly you will notice that they are pretty much exactly the same design (except the teardrop is a pop top of course).

    I've had my NEXT for about a year now. Apart from a slight problem with PC hesitation due to the kill line shrinking I had no problems with it. They did a really good job of making it fit the measurements, its seriously comfortable!!!

  15. Quote

    but I'd recommend buying a Protec (app. $40), put color coordinated tape over the ear holes (unless your doing CRW), make elastic pockets for the audibles



    I don't know how common this is but I had serious problems hearing my protrack when I used with a protec. It was real easy to mount it but the wind noise was loud enough to completely drown out the beeps.

    I tried lots of different ways of mounting it some with better results than others. But the best I got was being able to hear it about 50% of the time.

  16. Quote

    Exactly. The point is that risers are easy to replace, while harness is not.



    Personally I'm not that bothered about how much it costs to get things fixed. However I would be pissed if a hard as hell opening cause damage that meant that the harness wasn't landable instead of just the main/main risers not being landable. B|

  18. Quote

    TSO standards require that your ripcord DESIGN pass the 300 lb./3 second test



    Is this typical of the TSO standard. IE how much of the testing done for the TSO is pure design testing as opposed to testing the materials and the finished product

    Quote

    The amount of incoming material testing I have to do now is at least three times what is was in the past, because of the generally lower quality of received goods.



    This is starting to worry me a bit. If the quality of materials fluctuates (pins, webbing, etc) and there are sections of the TSO standard that only apply to the design, how many rigs out there wouldn't pass the TSO because the quality of the materials has changed since the initial certification???? Very scary :S

    Think my next rig will be a vector ;)

  19. Quote

    but the immediacy of the dangers inherent in skydiving may have kept this mentality from prevailing throughout the sport.



    Its all about the perceived danger instead of actual danger. There is little doubt in any jumpers mind about what is going to happen if they don't manage to get a canopy about there heads.

    This is both a strength and a weakness. People tend to think about safety, but only on the freefall aspects of a jump. When in fact its the canopy ride that most likely to cause serious injury or worse, but because the danger isn't staring you right in the face people can get complacent about it. I feel this is the biggest safety problem with jumping, the same is probably true of scuba diving

  20. Quote

    That's why we test 100% on ripcords...300 lbs. for 3 seconds



    Just out of interest, what proportion of the ripcords you make fail the test and get binned.

    Is this a common tests for manufacturers to do, or is my next rig going to be a vector ;)

  21. Quote

    Not so. I've seen some back-mounted reserve S/Ls with no AAD and my rigger told me that it's not manditory here. In the US it is however. That is not to say that individual DZs don't have a rule on this for their own gear.



    This sounds a bit strange. The BPA opps manual states that student piggyback equipment must have an AAD and an RSL.

    Quote


    2.2 Piggyback

    2.2.1. The following Wing Loading criteria should be applied to main ram-air canopies:

    a. Ab-initio Solo Student Parachutists - not to exceed 0.8 lbs/sq.ft.

    b. Solo Student Parachutists not including Ab-initio. - not to exceed 0.85 lbs/sq.ft.




    SEC 6/PAGE 1/AUG 2001

    N.B. The following exceptions to apply to the above:

    Where the Canopy’s Manufacturer has published advice that a higher wing loading is suitable (when the manufacturer’s higher limit will apply).

    or

    Where the person has logged previous relevant parachuting experience.

    or

    Where the Student Parachutist is above average fitness, his/her CCI believes a higher wing loading is appropriate for him/her and the CCI has recorded clearance for a higher specified wing loading on the Record of Training.

    2.2.2. The static line must be continuous from the deployment bag to the point of attachment in the aircraft.

    2.2.3. The equipment must be fitted with an automatic activation device (AAD) and a reserve static line (RSL).

  22. Quote

    This, to me anyhow, supports the static theory. Sounds to me as though static electricity is activating the cutter only. This would almost have to be the case since the units that fired were not powered on.



    I don't think the cutter is being activated directly by the static (I wouldn't have thought there would be enough energy in a static discharge to do that). It's more likely that the static is effecting the firing circuitry. This is still possible when the unit is "off" as the unit will never to completely off unless you unplug the batteries, as the power switch isn't a hard power off. It will probably just put the unit into an extremely low power hibernate state, where some areas of the system are still powered.

  23. Quote

    Even if it was a complete wad of junk, I'd ride it down to a lower altitude. Chop a canopy at high altitude and you'll never see it again. Besides all that altitude gives you a lot more time to try and save the situation. I've corrected malfunctions that I was planning on cutting away from because I had the time.



    I see what you are saying, but I would be worried about getting obsessed with trying to clear it, and loosing track of altitude. Your decent rate on some mals can be reasonably high.

    Plus I can imagine that being under a nice spinning lineover or something wouldn't be to pleasant either ;)

  24. Quote

    Hesitations are bad, in several ways. I'd fix it immediately.



    Tell me about it.

    I only noticed in the last few weeks when I started doing some hop and pops because of bad weather. Got a local rigger to replace the kill line and jumped it this weekend. hay presto no hesitation, also no twists (which I had always assumed were just due to bad packing)