Zahry

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Posts posted by Zahry

  1. Quote



    I'm curious about where the closing loop attaches. I can see the cutter on the left side flap. Or is it one of those 2 pin jobs?

    Quote

    Hi Michael - it is 2 pin system. If you'll ever come across this system be aware the closing loops must be tight. If the closing loop stretches a bit the pins will became lose and quite easy to knock out (you'll find rigs have loose closing loops quite often before the rig is due for repack - mostly it's happening gradualy)




    I'm not so partial on their elastic stowing system either. What is the mbs of that elastic shock cord? What's it's maximum breaking strength?

    Quote

    I'm not sure what the MBS is for the material strong uses but for shock cord/bungee cord generaly it is min 500 punds and more. In case you'll have a hangup/baglock it is certainly not going to break. (I'm not sure if it is desired feature on reserve system ... ;))



  2. Quote

    :)
    Tomas, if the photos you show on the housing are from a system in service how do you rig & jump that system ???

    Quote

    I do the rigging with great care. As you figured out the DHT hasn't earn my trust and I'm watching the equipment very closely. The gear doesn't have my trust exactly because of similar sudden component failures



    It looks like the system is packed for use - WHY ???
    if there are closing loop fibers on the SHARP end of the housing = Grounded system.

    Quote

    I've closed the rig because I needed to figure out what was going on and how the housing could get close enough to the closing loop and damage it so severely in such a short time. I didn't wanted to change the housing without investigating what could cause the problem. It could be bit contra productive



    The closing loop itself looks out of service too.
    Quote

    it was shredded to pieces - quite scary considering it was almost new



    If the housing or any housing on a parachute does NOT have the rounded finish metal cover end it should not be used - see all housing in use on parachutes Sport & Military.

    Quote

    Tell it to SE and check every housing on DHT with plastic ends. You might have a nasty surprise. When our retired rigger wrote his concerns to SE in 2005 they told him they've put there plastic ends there so the sharp edges can't do any damage ...



    Did you informed SE about that ? or it came up only after the CZ fatality?

    Quote

    It was addressed to SE in 2004 - 2005 by few NZ riggers and the concerns were dismissed by SE



    You also said that SE report show some ??? does the TI involved in the fatality was a DHT TI ?

    Quote

    not sure what you mean in first question - I'll find out about the other one



    All time you are pointing on unsafe & risky points on the DHT you should STOP rig & jump the DHT's at your DZ - stay behind your words.

    Quote

    I'm doing all I can according to our law and regulations.



    Again, did you ever reported SE about all the points you came up with ????

    Quote

    Yes, All those concerns about housings incl. issues with risers were reported to SE in years 2004 and 2005 ... and all dismissed the same way as they dismissed the potential risk involving MR425 and the "reserve" system.

    That's why this time I've decided to share my concerns online on public forum instead sending private emails to factory because, as Tom said, internet has a memory and it can't be so easily denied in future.



    Be Safe !!!

  4. If anyone thinks there is nothing wrong with the system. Here are some photos of the disputed design.

    The parts were inspected on friday (25 jump check) and since the inspection we did 7!!! jumps only on the equipment. During the inspection there was no visible damage to the loop, plastic, housing or the stitching. Today morning when I did few random checks I've discovered the damage. What you see on the photos is the housing cutting its way out through the plastic.

    How does it happen? The 3 ring system in certain configuration in freefall can push the housing into the plastic. The housings are mostly improperly finished (just cut with exposed sharp edge - every single one I ever seen is almost the same - some worst, some better) and when pushed into the plastic the vibrations from drogue can help cut it its way through. And if there is rough sharp edge (just like in our case here) it goes through like a chainsaw. On the Detail you can see bit of the loop still caught on the rough edge.

    It looks to me not just like only one design flaw but a whole bunch together.


    This rig has about 1 500 jumps and the housing was changed 3 months ago (the numbers are from top of my head - the exact numbers are recorded in maintenance book @ DZ. If anyone is interested I can provide the exact number of jumps, mothly average and DOM)

    I think the same thing in worst stage killed the czech tandem pair. When I've asked czech autorities about the other two accidents Tom mentioned I've discovered there was only one accident involving housing on risers jamming cuttaway (TM cutted the riser loop) and nobody knew anything about the other two accidents Tom mentioned in this forum. - maybe it was just misunderstanding and it happened somewhere else ... but there are other disconcerting fact. I found out the reserve packing card has been provided to Ted and Ted has been reminded he has seen it before publishing his press realease - and than he stated he hasn't seen it (you can check it with czech autorities as well just like me) So, can I trust the rest of it what the SE says?

    Also, I was unable to find where the DHT manual states the owner must keep inspection and maintenance records other than usually found in reserve packing card. (I was unable to find where it states the rig has to be sent back to strong after 8 years as well - but it might be just my fast reading ...)

  6. Hi guys,

    I appreciate what you are saying. I agree Strong has one of the best customer services over the world - full stop. I agree and appreciate back in the day they vastly improved the safety of tandem skydiving (Ted was the guy who started the whole thing if my knowledge is right).

    So I guess you might wonder why I'm poking into things like that.

    The reason is Teds Press Release about the last accident. He torn the guys to pieces (with grace and beauty) but nevertheless he literary thrown 100% of all that sh.. on their heads and walked away with SE sparkling and shining as a diamond. (As my friend explained me now, that's quite common practise in states and it is something to do with so many hungry lawyers there). The thing is - most of the world is outside states and they don't have to necessarily know or care about how it works there (revert the sides if necessary and you'll find you are not different). Unfortunately lot of people took the Press Release seriously as a final report and they think the case is closed. No - it isn't. The properly investigated official report hasn't been released yet.

    Just for curiosity - revert the sides.

    Imagine if the same accident has happened in states on Czech equipment. How would the press release looked like? I'm sure it would contain something like that: dangerous design, errors in construction cased by ignoring latest findings in safety, inappropriate testing by manufacturer, incomplete instructions and maintenance guidelines and so on ...

    I think no one should be complaining about what I'm doing because in SE they are doing exactly the same thing. I'm just looking at the coin from different side.

  7. Quote

    Tomas, I don't consider responding to you personally "a waste of time", except for the fact that it is clear that you are looking for a way to warp anything that I have written to suit your agenda.



    Hi Tom, I'm not putting worlds in your mouth - I said That's how I can interpret your answer and the area was clearly marked by >>> <<<. I'm sure there is lots of other ways how to interpret your broad answer. I'm getting a lot of information from you but not much relevant to what I've asked and I'm feeling like you are avoiding to give me a clear straight answer.

    For the record here and your information.

    We don't do handycam here (outside camera only) and I don't know anyone who doesn't do regular gear/handle checks and we are very strict about it.

    Thanks to good maintenance and HOP330 our malfunction rate is about 1 malfunction per 2 500 jumps (before hops it was about 1:800). During the period I'm working here as a DZ PT we've done more than 30 000 tm jumps with 0 equipment failures - and that's definitely NOT because of DHT good desing and easy maintenance.

    I dare to say if I haven't had an excellent knowledge how the system works and why and where are the flaws and weak points we would definitely had an equipment failure within those 30 000 jumps. Keeping the gear in excellent shape and constantly reminding everyone where the weak points and flaws are doesn't make me really popular but it keeps the circus going and everyone is safe. Everyone who has been here said they haven't seen Strong Equipment in such a good shape yet. Does it say I'm not doing my job well or I don't care?

    I can take care of the maintenance very well and I can keep everyone aware. What I can't do ANYTHING about is the design and how the DHT "reserve system" works .

    The only malfunctions we had here within last few years were tension knots and rarely lineovers and linetwists. That means deploying reserve on low speeds mainly. I'm asking once more again:

    What is going to happen if the passenger decide to kick when the TM pulls the reserve (there is very little airspeed for the TM to work with and some passengers really don't help) and the pilotchute gets caught on passengers arm (That's in example - I think something similar has happend in Cross Keys). What is the outcome on DHT? (I've heard in Cross Keys the TM and passenger died - it seems like it confirms my theory what would happen ...)

    Some questions for the equation:

    On conventional freebags the force necessary to pull out freestowed lines is almost zero and once the first closing loop is pulled out running loop releases the pressure and there is almost no force needed to deploy the other one - That's ensuring the lines will be fully stretched before the freebag opens and it allows even the half of the bridle create enough drag on lower speeds to deploy the lines, open the freebag and pull the freebag away. The whole system dramatically reduces the danger of temporary bag lock, linetwists and lines and bridle entaglement. THERE IS NO SAFETY FEATURE LIKE THAT ON DHT

    So - what is the force necessary to pull out the lines on DHT "freebag" and what speed is necessary to create the necessary drag if the pilotchute is caugt on something (for example wrapped on passengers arm) and therefore only the bridle is exposed.

    What I'm telling here is: On Strong DHT in this scenario (unless someone knows why physics shouldn't work in this case) the tandem will end up with temporary baglock and linetwists or total baglock or lines and bridle entaglement because the bridle won't have enough drag to pull out the lines quickly and straight, the turbulence will have plenty of time to spin the bag around the anchor points (fixed closing loops) and it can cause entanglement with the bridle.

    If you think I'm wrong I can give this scenario with the relevant information to several independent authorities and institutions and we can ask for official opinion. Also, it should be quite easy to simulate this scenario with dummy in open windtunnel without putting anyone in risk and we will have accurate data from real test. You know - you can put the rig on dummy, anchor the dummy (leave bit slop on ropes to allow a little bit of movement for the dummy or put it on its side) , wrap the pilotchute on some arm or leg, start the engine and start increasing the speed (increase the wind velocity the same rate as tandem accelerates without a drogue) and watch the results... you can even push the "freebag" out prematurely to make it bit more realistic. The bag in a real life will not likely stay in container if tandem thumbles on opening (remember - in our scenario they thumbled - that's how they got the pilotchute wrapped on their body in first place... and watch the show

    I'll be very happy if you'll prove me wrong but I don't think you'll be able to do it without chaging the laws of physics or with independet comision supervising the test.

    I guess lot of weekend wariors and tm wannabes will say they shouldn't thumble and I'll say they have to learn lot more about what can happen in tm bussiness.

  8. Hi Tom, Thanks for the answer and for the time you are spending answering my questions. I guess you think it is an utter waste of time but I've got few points from your replies. I'm happy to cooperate on making the DHT safer and I'm sure I'll be able to offer more than just criticism. Although I'll be happy to discuss those matters via email some things I would like to discuss here open to public instead of hiding it. I believe if we won't keep our knowledge and experience as a secret somewhere out there could be someone with inquisitive and inventive mind and that person could come with something important later on.

    Based on your information I'm not concerned about AADs at all - those are well sorted, there is no problem and I'm happy about it. It wasn't my concern before but it is always good to know these things.

    Back to the subject:

    Your answers were nice and curly but let me get it straight and simple. That's how I can interpret your answers. >>>

    1 - Have you based your press release on speculations without thorough physical testing?

    1 - No - you did some testing and you believe it was enough

    2 - Have you done physical ground tests on old and new equipment with different closing loops lengths and with different canopies?

    2 - No , you haven't testing like that because it shouldn't happen.

    3 - Are you aware stowing lines in elastic loops with plastic chokers on (or even without plastic chokers) can cause reserve bag lock?

    3 - Yes but you are saying it is ok because even on significantly improved systems is still chance for baglock (even thus the chance for baglock on modern freebags is drastically decreased compare to DHT freebag)

    4 - Are you aware stowing lines in elastic loops with plastic chokers on (or even without plastic chokers) can cause horseshoe malfunction on reserve or reserve entanglement during unstable reserve deployment?

    3 - Yes , but you choose to ignore it because you are sure it will clear every single time (I'm talking the case when reserve pilotchute gets wrapped around some part of TM/passengers body and can't be quickly removed)
    <<<

    I've acknowledged there is safety limit of jumpnumbers on the gear and from whole discussion I've learned you have the same opinion as me it shouldn't be exceeded. The life for DHT is 2 000 jumps. To clerify it - is it recommended number or mandatory? If it is recommended number only what's the mandatory guidline for discarding the old rigs (my employer won't be happy if I'll tell him but if you as a Strong rep will do a clear statement it will have completelly different value - although DZ owners won't be happy at all)

    I guess it is lot harder to learn things we don't like - for everyone - and I guess the truth will be somewhere in the middle. Not as good as you are saying and not as bad as I'm saying neither. I think now is time to stop talking about it and it is time to do something about it. I'll contact you through email and we can go from there.

    Regards Tomas

  9. Quote

    It's disappointing that DZ.com allows what is essentially a personal attack albeit on a company.
    I was under the impression this sort of post got people banned.
    >:(



    Opening up a disscussion about serious problem and asking for explanation is NOT a pesonal attack on SE. Altrhough I'm using pointy arguments I'm using apropriate language and my arguments are based on very easily verified facts.

    If you don't appreciate freedom of speach move to Iran or North Korea - I'm sure you'll be fully satisfied with quality of their censorship.

  10. Quote

    Quote

    Looking forward to hear from you, Tom



    Honestly Tomas, your not going to hear much from me on this thread. As clearly evidenced by your postings on both this thread and the incidents forum, there is no amount of evidence or information that is going to sway your opinion, you will "point/counter point" this for all time.



    Hi Tom,

    1) I'm not surprised but disappointed you are finding my concerns based on field experience just "being negative". What I'm surprised to hear about is Mr Strong has spend 30 000$ just to try out for himself if vigil and Argus cutters can cut the loops (not my business - true, it's his money) ... but I'm glad you haven't had any problems on those reserve rides - I know enough people including myself who don't have as good experience as you do.

    2) I've spent some time verifying your reply about the volumes and after several physical experiments (no speculations) I've discovered a few very disconcerting facts which I would like to share. When I've tried to pull the bag out I found it was impossible to pull out even HOP330 out of new container with tight closing loop. On the other hand it was quite easy to pull out d bag with ANY CANOPY out of ANY older rig with stretched closing loops (5 year - 3200 jumps). Why my physical test didn't confirm your speculation?

    Can I ask you to answer a few simple YES / NO / CA (CAN'T ANWER BECAUSE OF POSSIBLE LAWSUIT) questions?

    1 - Have you based your press release on speculations without thorough physical testing?

    (Y/N/CA)

    2 - Have you done physical ground tests on old and new equipment with different closing loops lengths and with different canopies?

    (Y/N/CA)

    (following questions are regarding general safety)

    3 - Are you aware stowing lines in elastic loops with plastic chokers on (or even without plastic chokers) can cause reserve bag lock?

    (Y/N/CA)

    4 - Are you aware stowing lines in elastic loops with plastic chokers on (or even without plastic chokers) can cause horseshoe malfunction on reserve or reserve entanglement during unstable reserve deployment?

    (Y/N/CA)

    I'll appreciate if you'll answer all questions honestly and with simple Y/N/CA

  12. Quote

    Trust me, the factory has been hearing about flaws in their equipment and have been developing solutions (drogues, Type 7 risers, Slimline buckles, double main closing loops, Anti-Line Slump bags, Y straps, etc.) for decades.


    I know about these changes and interesting fact is that almost every change can be named " In memory of ... " The identified problems and field experience was usualy ignored or disregarded untill there was fatal or very serious accident.

    Quote

    The danger - of discussing this on a public forum - is that it will feed the lawyers.


    I thought safer rig means fewer accidents and fewer accidents means lot less problems with lawyers.

  13. Hi Rob. I guess we are not on the same page at the moment. Developing theories about the last fatality wasn't my intention here - that's why I've started the new thread separated from the accident forum.

    My reason for starting this tread was to open up a discusion about DHT Design flaws and Safety and Maintenance hazards to wake up people from blindly believing in their equipment without knowing what's in there and how it works. (i know out there are many people otraged because they are scared they'll loose their flase feeling of safety but there is lot more in stake than just hurt feelings)

    I would like to expose the huge potential for problems on DHT (specialy the "reserve" system) and I hope the knowledge will help to change something and prevent future accidents

    - or do you think there is nothing on DHT what deserves attention, revision and improvement?

    I'm not sure what's your opinion about this but I think in comercial skydiving should be tendency to make work euipment and work enviroment more safer and if we discover something is wrong we should do something about it. It is Not just because of us but because of the paying customers as well.

    Looking forward to hear from you, Tom

  15. Quote


    Oh my god. I can't beleave you've got me defending SE.

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    I'm sorry - I didn't intended to do that :)



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    I hope you don't gonna take what I wrote as a personal attack on you or attempt to offend you. I just like to say the things straight without running around too much and cut to the chase



    How much is to much?
    Quote

    you guys were setting the first GLOBAL safety standarts 25-30 years ago. Good on you and THANK YOU for that.

    I acknowledge there was breach in safety which triggered the last accident and without breaking the rules the chain of events would never started. We all agree on that?

    What i would like to point out it wasn't the closed main container what really killed them. It TRIGGERED the chain of events BUT it should ended up with drogue in tow.

    This wasn't the only acciden - apparently there was few more similar accidents way in the past as well but it was dissregarded with comment "what are the chances it is gonna happen again if we will maintain the gear better" - And it happened with set 400 and MR 425 as a main as well.

    I gave it a very good thought yesterday and I've checked a few facts. I suspect the reason why it wasn't problem back then is because SET400 and MR425 are big, slow with very low performance so the main was spinning so wildly and the reserve had enough time to deploy around even with the plastic chokers on.

    There is no question there is huge design flaw in the way how the main container is closed - otherwise the main didn't escape from container before it was opened and it ended up with scared TM and drogue in tow AS IT SHOULD. (yes - the design flaw is the hot fix when strong changed short flexi pins to long ones and double closing loops).

    Next in the game we have fast spinning main canopy and with another main canopy deploying next to it (I know SE calls it a reserve but the name doesn't make it a reserve. I can call my bike a rocket but it doesn't make it go any faster).

    All those things combined together and you can have a lot of mess around you.




    For the record SE lopo's are still one of the best pilot canopies out there for the range of speeds for which they were designed.

    Quote

    for the record - I agree - I'm sending pilots to buy them as well as many other quality emergency chutes from other companies - and without any hessitation or regret. I appologise if I ever mentioned LoPO is a bad emergency chute. To make it clear - What I intended to say was I'm gratefull to all those in past who said "we can do better" so now we don't have to use LoPos as our main tandem canopies. (I'm NOT saying it is a bad rescue parachute!)




    You have to judge things based on what they were designed for.

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    That's what I'm exactly talking about - I wanna have a main as a main and reserve as a reserve and emergency parachute as an emergency chute. I don't wan't anyone mixing it up or calling apples pears.


  16. Quote



    You say “I'm not trying to bash SE down, I'm merely trying to make the old dinosaur to move!!!”

    Well it comes across totally different. Do you really think that this message will be heard at all? I know there’s been much talk about a new design going on and many people wait for it.

    Quote

    sure, I've heard the rumours as well. The "new" design rumour is around for so long it will be old design soon. Do you belive those rumours will come true in near future?

    Maybe some information hasn't been shared with me. I you know something I don't know I'm ready to listen.
    - what development has been done on the new system so far.
    - In what stage the development it is
    - what is the announced date for release of the new system?
    - is it going to be certified according to tso23d (or at least tso23c)?



    And I have a bet for you: If they presented a new design within the next month people like you would be outraged “why it took the so long to come out with it” and “why did we have to jump the old stuff for such a long time?” YaddaYaddaYadda

    Quote

    Low blow



    Next point - you say tandems are a death trap: Did you, in your long career as a packer and rigger (how many thousand of packjobs have you got?)

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    about 10 000 - 20 000 packjobs, several hundreds reserves (about 1 000 if I'm counting only skydiving equipment) 7 years of maintenance 24/7/365 and 5000 jumps

    Now to return my favour - what is your knowledge background and experience?



    ever take the time to read the warning label in bright orange on mains, reserves and containers? Bingo! Skydiving is a fucking minefield. Welcome to the real world.

    Quote

    you mean the statement: "even properly packed and maintained parachute can fail?" funny enough I read it. Question for you - did you ever bothered to think about it for a moment? Why is it there and what purpouse it serves?

    That statement is for legal protection of factories to protect them agains possible lawsuits. By telling you the parachute can fail even if properly packed and maintained they are telling you there might be some unforeseen design flaw which can cause to malfunction of the system.

    Otherwise - what's the point of maintaining the parachutes if it can fail anyway, eh? (For the record - That was a rethorical question - I'm not beeing actualy serious)



    And it is your F******* job as a rigger to keep your jumpers safe.

    Quote


    Thanks for the advice, I almost forgot i should do that. I was just about to pick up the bell and start ringing and yelling "everything is ok, belive in SE almightiness. There is absolutely nothing wrong with. DHT is spotless state of the art equipment."

    Oh man, thank you - you've put me back on the track.



    If you have worked out how YOU can improve some detail, get in touch with the manufacturer in question. If it is something that hasn’t been thought about already and your invention comes in handy, I am sure it will turn up in the next update.

    Quote

    ok - here are some suggestions for updates.

    Update 1- replace the reseve including the so called "freebag" with tandem reserve with TSO23d and real freebag

    >>>If they can't design functional reserve themselves they can purchase reserves from other companies - it saves a lot of money and I don't care if it is made in US, EU or Africa as long as it works as it should. If they don't know who to ask I'm happy to forward some emails. If not - state the reason why.

    Update 2 - finish the hard housings properly - do not leave the sharp edges hidden under the plastic.

    >>> the ends can be finished the same way as the hard housings on risers. If not - state reason why.



    Speaking of updates: You criticise, that DHT-design is just one giant patch. I bet you post this from a computer running on windows. Updating gear in small steps (as being done on DHT’s) is _IMHO_ an evolutionary process. You do not have to reinvent everything from scratch over and over again to keep a system and a good team running.

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    OH - Are you still running updated DOS 32 or Win 3.11??? WOW!!!



    Heck I could even cite Bill Booth that with every safety update idiots evolve as well finding new ways to kill themselves (and others) making the whole process nearly worthless

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    oh - in that case we should stop trying? I know making something safer is a hard job - just right now I'm finding out the hard way



    Your other point – the MR425 reserve not being designed as a reserve: Can you spell Decelerator or Raven? In the rare case of a malfunction - again IMHO – I want my reserve to be as big and strong as possible. I need Kevlar to do this? Fine – just use it! If I blow up a cell or two being at terminal or over with a master 425 I’ve still got something larger left over than if I jumped a PD 360. And if I go for a reserve-ride I surely don’t want the fucker to rock all over the sky stalling and recovering because of setup/trim issues. Thanks – I’ll stick to Masters!

    Quote

    personaly - I would preffer something what works properly. Just for my curiosity - how are you intending to land the MR425 in case of blown centre cell. I can't figure out how to land a canopy splitted in half ...



    I am sure someone really clever will come up and state the superiority of the sigmas.

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    it doesn't have to be a really clever person to do so



    Well that was Booths shot to get rid of all the inherent design flaws of the vectors without getting the new design totally free of (possible) bugs. Even the much acclaimed Skyhook had a major fuckup needing a “ghetto-fix”

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    are you saying UPT should insted of fixing the problem correctly put there quick addon fix which will create more problems than it solves? (as it often happens with SE?)



    You ask if proper maintenance of tandem equipment is enough to keep TI’s safe out there: Honestly I don’t know. Remember: This is still a minefield. But it is the most vital first step never to be missed.

    Quote

    ok, you have the chance to put your cock on the block. Do 10 - 15 tandems a day and maintain your rig yourself including book keeping and maintenance records

    Show if you put your money where your mouth is



    Still another point: TSO’s – do your reading and find out if ANY manufacturer has multiple TSO’s for one design. AFAIK everybody’s just got one. Vector 1 & 2 ran under the original wonderhog TSO (If I am wrong on this, correct me, I’ll freely apologise)

    Quote

    those are already outdated systems with replacement in place - sigma.



    I definitely know how hard this whole incident (how I hate that word) must be for everyone directly involved and I can understand that many people want to get the spotlight off the people involved

    Quote

    Wrong - I'm not directly involved. I'm living in NZ.

    The last accident was just the last tiny drop which filled the pot.



    – but in this process you blur the lesson: Do what you want and how you feel if you go out alone. But under no circumstances leave the proven path when it comes to taking a student/passenger/punter/peace of living cargo with you.

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    Man, Blind faith and Fanatism. Hello - we are talking about equipment here.

  17. Quote

    Quote

    ... unfortunately average passenger is now more and more heavy



    Tomas, I'm sorry, I need to comment on the logic of this one. If you follow the manufacturers weight limitations, it doesn't matter how fat we are all getting. If the student is heavier the instructor must be lighter, etc. The weight limitations do not guarantee safety, but they help.

    Quote

    yes



    As far as the original thread about the fatalities in the Czech Republic, well, haven't we found that the owners/users of that Dual Hawk did many, many things wrong?

    A properly maintained and properly used tandem system from any manufacturer is acceptably safe.



    Hi Garry, I agree, if you put your hart and soul in it - anything can be maintained and serviced. I'm sorry for beeing harsh but you could use even condom 1000 times if you'll maintain it properly and use it carefuly - but would you do that?

    Maintenance was definitely one of the mayor factors of the accident - but not the only one. And don't get me wrong - I'm not trying to apologise them for overlooking the one broken part. That's one link in a chain. Size of the canopy? It looks like their disgusting marketing trick - "buy set400 and you are invincible". It would make me laugh if is wasn't so outrageous - volume is almost the same. Do we have to measure now exact volume of each packjob and readjust closing loop lengths before each jump? It sounds ridiculous

    Scary thing is - any of those dozens and dozens weak points and flaws which can go wrong with strong DHT - EACH OF THOSE can start the chain of events resulting in someone DEAD. It's like loaded gun with hundreds of little hidden triggers pointing at people. You can maintain those triggers - I'm not saying it is impossible - I'm doing it every day but once you'll forget one - the gun will fire straight into your face. I have a feeling you know it, right?

    long story short: Strongs report is NOT INDEPENDENT and they are hiding, ignoring and twisting impontant facts.

  18. Quote


    Now if you want to set down and brain storm ideas mods and upgrades for improving the strong tandom I think that would be a great thread. But with your wild ravings your comeing off as a borderline lunitic tool.

    Lee



    Hi Lee, first step in improving things is identifing if there is a problem, what kind of problem it is and if there is a way how to correct it - That's why I've started the thread.

    I'm pulling skelletons out of someones closet right now but it wasn't me who put them in there...

  19. Quote

    IMHO: with this whole arguement you try to divert the discussion from the main cause of the incident which triggered the whole debate: Non-existing maintenance and care

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    No - it is not. The whole discussion is here to show there is lot more to it than just poor maintenance and care and expose the behavior which seems to me is totaly suspiciousl



    maybe - I am not a rigger, just a strong rated TI, so my opinion is surely biased - DHT's are high maintainance. but maintaining DHT's and keeping them safe, seems pretty easy to me. ever tried to change a kill-line on a vector?

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    :-) yes, I've tried. It is very easy job



    this is high maintainance in my eyes. take this as a sidenote, because i have no interest in bashing any manufacturer for how they design their gear like you do

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    I'm not trying to bash SE down, I'm merely trying to make the old dinosaur to move!!!



    if you really don't like strongs and working with them convince your dzo to buy other gear, this is a free world.

    Quote

    I'm trying - and we've got first sigma here and I've got for us one different tandem system for free. And I tell you its not an easy job to change something. Money is the name of the game and lot of pople preffer to close their eyes, cover their ears and shut their mouth instead of doing something



    until then it is your job as the dz's rigger to keep any tandem equipment in a working and safe condition and stick to manufacturer recommendations and safety bulletins by the book - which the dz where the incident happend failed to do

    Quote

    Yes, it is a good advice BUT Is it enough?


  20. Quote

    " ... Flexipins have to be checked frequently because of the damage caused by kinks in the housings and the sharp edges of unproperly finished housings ... "

    ..........................................................................

    This problem is not unique to Strong.

    Most of the tandem manufacturers (Jump Shack, Parachutes de France, Strong, United Parachute Technologies, etc.) have issued Service Bulletins reminding us to inspect flex pins on a regular basis.

    Flex pins are "high wear items."

    If you are not willing to inspect - and replace - high wear items, you should get out of the student business!



    Yes - other systems has a few issues as well. BUT strong DHT has almost the same number of problems as other systems all together that's not just flexipins. Of course you can take a DHT and start pointing on other systems and say "See - this rig has tis problem common with DHT, THAT rig has THAT problem common with DHT". Try to do it the other way. It looks like the DHT has enough problems for all the different systems available on the market.


    Lets compare two bigest players in a game in USA. UPT and SE -

    UPT started with VECTOR 1 and no drogue and say PD 360. They went through Vector II, Vector III and different main designs (surelly it wasn't for free) and ... NOW THEY HAVE A SIGMA!!! It might have still a few flaws but they proved the will to learn, change and improve. And it is to our mutual benefit.

    Lets have a look at SE. Third of century ago they started the whole thing with DHT and MR425 ... and now ... we STILL have the same DHT and MR 425 with a few not really functional mods. And it looks like ALMOST EACH minor mod had to be paid for by human lives.

    WHAT DOES IT TELLS YOU?

  21. Quote

    " ... MR425 hasn't been intentionaly designed as a reserve (as far as I know it used to be a main and it was opening pretty hard and from what I've heard not really reliably) and the kevlar lines used (who knows why?) are transfering full force of the opening shock directly into harness and back to canopy - not the best feature if you need to slow down quickly on short distance (to make the opening bearable the MR425 has to be flat packed and the nose is rolled/folded ..."

    ...........................................................................

    Ah!
    The arrogance of youth!

    Perhaps you are not old enough to have jumped Pioneer Hi-Lifter 370. Performance Designs 360 and Strong 425 as mains.



    I've done some jumps on PD 360 and VS 386 and some things just did their job but their time is way over. I think you agree it is easy and inexpensive to replace main canopy but replacing whole system is incredibly expensive. Question is - How much is too much?

    Quote

    I jumped all of those canopies back when they were fashionable as tandem mains.
    I made 1,500 jumps on F-111 tandem mains before SET-400 was introduced.
    Trust me, Strong 425 was the "least of the evils."



    It doesn't change the fact main canopy designed as a main canopy is a main canopy - you are a rigger and a very good one. You know reserves are designed different than mains because there are required different opening characteristics and the same is valid for deployment system on reserves.

    Now is year 2009 not 1980. I've heard the same arguments before "If you are complaining jump LoPos, ParaCommanders, Thunderbows" - and I did. It made me appreciate those people who stepped up and stepped over those dead legends and moved us forward. And I bet once you were helping to push the safety level up as well ...

    Quote

    Maybe I should relate a phone call from a nearby DZO. "Good news! You got another save - on a Vector Tandem reserve - last week. Bad news! The opening sucked! It was stalling and rocking all over the sky!"



    I agree. Breaks set so deep it stalls after opening. It is a cheat how to beat the tests on tandem terminal. There are already more modern and better reserves on the market. But you can't say MR425 is not bad because VS360 is not good - it doesn't make sense

    Quote

    Granted, Strong 425 main canopies only lasted about 600 jumps, but solo main canopies - made of the same materials (F-111 fabric with Dacron lines) - only lasted 600, maybe 800 jumps before retirement. By 800 jumps, most F-111 canopies flare like bag-locks!

    ALL F-111 canopies open harder than modern ZP mains.
    What is your point?



    my point is in these days we know more about materials, openings, construction and safety. What's the point to throw it out of the window and ignore it?

    Quote

    As for Kevlar lines and reinforcing tapes on Strong reserves ... they were the best materials, with the highest strength to weight ratio available, when that system was certified back in the early 1980s. Granted, kevlar suspension lines only survive a few dozen hard openings - before they start snapping, but reserves are limited to twenty deployments (before retirement), so what is your fuss????



    As I wrote before, now is year 2009 not 1980. There are far better materials and technologies now. Kevlar lines worn by constant rubbing on sharp edges of plastic chokers can snap any time without any warning - and unless you know exactly what you are looking for afterwards you'll never find it was exactly on the same place where the plastic choker was sitting before.

    Quote

    Modern zero-stretch lines like Spectra, Vectran and HMA transmit opening shock to the harness at about the same rate as Kevlar.
    What is your point?



    Come on, are you pulling my leg? Try the other one - it has a bell on it :-) - Spectra doesn't stretch? Since when and how that happened? As far as I know spectra lines still shrink and stretch in dependence on heat and weight applied ...

    Vectran and HMA - true. It doesn't stretch but have you seen it on reserves??? Those lines are used because designers want to keep the same trim over period of hundreds of jumps to keep the same performance on canopy with 10 jumps as well as 500. Zero stretch lines are for competition canopies to reduce drag and to help keep more constant performance and more constant recovery arch On top of it - Most people don't have a clue how extremely difficult is to design canopy to open reasonably with those lines and how complex is designing the opening.

    Tell me, was MR425 thoroughly tested and is it well designed for the purpose it serves?

    Was the MR425 intended to be used for hundreds of jumps as a swooping canopy/reserve as well?

    Quote

    Speaking of retiring Strong 425 reserves. Back in the 1990s, after we had 20 jumps on Strong reserves, we used to reline them with Dacron and put another 400 jumps on the, before the fabric wore out.

    As for criticising Strong's reserve packing methods ... that packing method was fashionable for mains back when the system was certified. I even used to pack my Strato-Cloud that way.



    Exactly - it is old way and time has moved on. Don't tell me now you'll let your dentist to do your teeth the same way they did it in 1890 or 1960? Back in the day you haven't had an option and no one knew better - now it is a different story

    Quote

    As for suggesting that Strong Enterprises design and certify a more modern reserve canopy ... do you have nay idea how expensive test drops are?
    Hint: solo test drops start at $800 per jump!
    A few years back, Strong re-tested their tandem gear at 600 pounds.



    So what. It costs $800 per jump. Everyone has to pay it - not just SE. If they can afford to make it safe that's bad - it's time to take it of the market than.

    Are you saying it is not good to question the safety of DHT because testing it and making it safe would cost money???

    On the contrary I'm well aware how expensive and how difficult (and that will be the main issue here) is to pass tests for tandem reserve. Especially if the reserve blows up on one of the 3 required jumps on tandem terminal with full weight on. Or if you find it didn't blew up but it would kill both the passenger and TM as well. Or on the end you find the canopy and people survived but because of those changes the canopy doesn't opens to slow on low speeds or stalls after opening - Does it sound familiar?

    Quote

    That being said, I believe that hanging more than 400 pounds of meat under a tandem is just asking for shoulder and spine and leg problems.



    I fully agree unfortunately average passenger is now more and more heavy

  22. >>> moved from prev forum <<<<

    Quote

    Quote

    Wow, That is a lot.
    Kinda scary that you have all these issues, but have 1000+ Reserve pack jobs and 4000+ jumps on the system. Why do you continue to pack/ jump the system if it is such a "death trap"?



    Funny you assuming I had all those issues. Learning is an interesting process and I found out good education and observation is sufficient substitute for my own cockups. I know the symptoms, I know the causes so why do you think I'll be waiting for the consequences? Long story short - why should I repeate mistakes someone has done before me in past?

    And why I pack it and maintaining such a death trap? Because I have a job to do and responsibility to the TMs. I want to give them the best chance they'll go home on the end of the day and I don't want to see anyone going home in a coffin. I'm well aware of the dangers of DHT and I have the knowledge I've got from riggers I've previously worked with - and they had to learn all of that the hard way (thanks Dave and Dave). That, in my opinion, is giving me the best chance to cheat the odds in this game of russian roulette.

    Long story short - if i'll quit someone else will come and it might be as well new unexperienced rigger who doesn't have a clue about the maintenance demads of DHT. And than you have a dead bodies walking to work every day. They just don't know yet.

    Unless SE will be forced to redesign and recertify their DHT to comply with safety standarts (hopefuly just because of good arguments not because of too many fatal accidents) there is nothing much going to happen except sometimes we will have to clean up the mess.

    The DZ owners don't want to or can afford to replace the gear because of the huge cost, SE don't want to admit there is anything wrong because redesign the system or recalling all the systems back to the factory would kill their company for good - plus there will arise the legal responsibility as well. And in middle of that you have a lot of confused people and riggers who have to deal with the pressure from both sides and take the punishment for someones greed, lack of good judgement and no sense of responsibility -

    I reckon now is the time to push back.


    Quote

    *** BUT you can get away with it by carefully inspecting the rig before each jump and GOOD MAINTENANCE



    Good idea, I think the tandem manufatures should adopt this.
    everyone who does anything with DHT has to remember that - but good maintenance doesn't fix the reserve system problem.

    Quote

    ***How can you justify such a HUGE design flaw on reserve system?



    While the Dual Hawk may not be the most modern system, It passed the same testing process as every other system.
    You can sit and pick out flaws/ scenario's in every system out there.

    THIS STATEMENT IS NOT TRUE. Exactly as you wrote - the DHT is NOT a modern design. It is one of the OLDEST systems (first i believe) on the market and it has been certified way in PAST when piggybacks and square canopies were still novelty and no one had a clue what can possibly go wrong. It is widely IGNORED FACT!

    As far as I know DHT has NEVER been tested to comply with present safety standarts. I couldn't find any records of retesting the whole thing again in recent years. The so called reseve system is a hard evidence it hasn't been done - it is just another main system with disconnected dbag with main canopy in it. Present standart is - the freebag should prevent horseshoe malfunction and baglock on reserve - and DEFINITELY NOT PROMOTE IT. The DHT is NOT up to present minimum safety standart. (and I'm not going into details about opening characteristics of MR425 which never been designed as a reserve in first place! And that's the whole core of the snowballing problems)

    If you want to compare DHT to other modern tandems I'm strongly engouraging you to DO SO. Have a look at each element of each system, how it works, why it works like that and compare it to others and ask yourself - what can passibly go wrong with those things. Nothing is just good or bad but as we learn more and more you can make yourself a better picture whats right and what's wrong.

    My conclusion is - The DHT is old rusty chain which constantly tries to break brak with no propper backup in place.



    Quote

    ***Skydiving is natural segregation of heroes and idiots ;-)



    ...and those who will pack anything for a dollar...



    ... unfortunately not those who sell anything for a dollar ...

  • >>> posted by [divnswoop] - moved from previous forum<<<<

    Quote

    Wow, That is a lot.
    Kinda scary that you have all these issues, but have 1000+ Reserve pack jobs and 4000+ jumps on the system. Why do you continue to pack/ jump the system if it is such a "death trap"?

    Quote

    BUT you can get away with it by carefully inspecting the rig before each jump and GOOD MAINTENANCE



    Good idea, I think the tandem manufatures should adopt this.

    Quote

    How can you justify such a HUGE design flaw on reserve system?



    While the Dual Hawk may not be the most modern system, It passed the same testing process as every other system.
    You can sit and pick out flaws/ scenario's in every system out there.


    Quote

    Skydiving is natural segregation of heroes and idiots ;-)



    ...and those who will pack anything for a dollar...

  • MOVED from discusion forum about another fatality related to DHT equipment.

    http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=3598486;page=unread#unread

    I would like to encourage all people reading my posts if you agree and even more if you dissagree with my opinions to COPY and PASTE the texts as it is or a link to this forum to an email and send it to EVERY TM and RIGGER you possibly know.

    We have a freedom of speach and the right to know what's really going on .

    Is Strong deliberately diverting our attention from real problems?

    Is Strong covering up dangerous design flaws?

    Is Strong DHT certified according to the present standarts?

    Is Strong DHT high maintenance demand reasonable workload or unjustified hazard?

    Why Strong DHT doesn't have a lot safer reserve system yet?

    >>> moved from previous forum<<<
    Quote


    I don't know you but you OBVIOUSLY have an ax to grind. In my opinion Strong Enterprises is one of the most reputable companies in the industry. The SET 400 is a very reliable system that by design has a lot of redundancy. I am a rigger and like most systems maintenance is key. To try and even suggest some of the things in your statement is hiding from the truth. Truth - The proper maintenance and training wasn't done. Truth - The manufacturer's approved canopies were not used.

    Regarding this incident the two truths stated above were both huge factors in this fatality and anyone with common sense would not try and argue differently.

    For what its worth I saw first hand an unapproved smaller canopy being used in a SET 400. This incident happened at Titusville around three years ago. The reason I remember the incident is because on deployment 1/2 of the reserve container was ripped away when the main canopy lines didn't deploy correctly.

    There is a big reason why ALL the manufacturer's recommend using a properly sized container for sport parachutes. Of course under your logic only Strong Enterprises is wrong when they suggest that some canopies are too small to be used with a SET 400 system.



    Hi, are we speaking here about the THRUTH in meaning I BELIEVE it is a THRUTH or are we talking about thruth based on facts?

    It looks like Strong is trying to carefully divert the attention and they are trying to cover something up.

    Here we have a few facts based on my experience as a packer, rigger and tandem master ...
    (done about 10K - 20K + packjobs, 6 years of maintenance on daily basis (fulltime job on busy NZ dropzone), done about 1000+ reserve packjobs and about 4000+ tandems on DHT):

    Strong DHT is a HIGH maintenance system with many design flaws, weak points and many mods and mods of mods. Surprisingly not too many people has died yet - I guess the main credit goes to the tandem masters well aware of the dangers related to DHTand riggers maintaining the systems rather than Strong Enterprises.

    About the accused main canopy problem. There is a difference in size but there is very small difference in packing volume. If Strong realy mean it serious with the volume of the packjob beeing main contributor of the accident, than ALL DHT systems should be rendered UNSAFE and grounded IMMEDIATELY. Simply - packing volume can change significantly in dependance on humidity, packjob, age of the canopy and so on and there is no guaratee the packjob will have the correct volume for the system to work properly even with approved canopy.
    Blaiming the difference in sizes of the canopies to be the cause of the problem is bit suspicious and smells with something dirty. The difference in volume is very small.

    Lets draw the attention to the more "hot" subjects.
    Who has a DHT please gab it and check following examples:

    - above mentioned improperly secured hard housings on main risers - bottom of the housing is free to twist and is very common for the housing to twist out during the approved period of jumps and stretch - potentialy jamming 3 ring system. During the packing inspection it seems for the packer there is a huge gap between the housing and the 3 ring system. That's when it is lying flat on the ground - if you bend it back (when you place the risers into container) the gap disapears (no point to argue - it's geometry - try it :-) ) in that stage the loop can hook up on the housing and once the canopy is deployed the housing can either slip out fromn the trap or get stucked there and jam the 3 ring system. If you need to cutaway you'll have a bad day.

    - above mentioned ripped off reserve corners - not so many TMs know whats the real cause of the problem. Mostly they blaime it on packers and risers. True but the cause is somewhere else. If you don't believe grab a rig and have a look into reserve compartment and focus your attention on the construction of the reserve corners. Without too much difficulty you should be able to find (unless the rig has been modified by rigger) the corners are held just by a few fairly weak stitches. There is a gap in stitching allowing through cypres cables. Mostly - this weak point is over the period of time more and more weaken by deploying risers and eventualy it is bound to let go. (it happened on almost EVERY rig we have here regardless of the canopy and packing volume of the canopy)

    - drouge release system is a chapter for itself and unless I want to start writing a book I have to take it very briefly.

    Housings are easily damaged and has to be changed frequently otherwise jamming cables inside.

    Flexipins have to be checked frequently because of the damage caused by kinks in the housings and the sharp edges of unproperly finished housings (I'm talking about those infamous plastic covers for the ends of the housings which has to be frequently checked and replaced regulary otherwise the sharp edge gets exposed and than the circus begins). It can jam the cable or the cable can snap by the base resulting in drogue in tow.

    I'm going to mention just briefly the drogue release cables wich can jam in damaged housings or get stucked on those sharp edges on housing ends when the plastic gets bit tired. In most cases you get just scratched cable but time to time the housing cuts into the cable and than you have to hope for the odds that's not gonna happen on the secondary as well.

    Also, there has been numerous problems with hard cutaways realted to cutaway cables, the geometry of the 3 ring system and the top attachement points. The 3 Ring can be pushed/bent away from or into TMs shoulder in dependance on passengers possition (just like a seasaw). It quite changes the forces applied through the loop to the cutaway cable and the geometry. Feel free to grab a rig and discover this interesting feature yourself - it is very interesting - the possibilities are endless.

    There is more but I don't want to write a book on How To Survive Jumps on DHT. That's a job for the boys from SE.

    All those things are VERY BAD and there in NO EXCUSE why it hasn't been redesigned and fixed - BUT you can get away with it by carefully inspecting the rig before each jump and GOOD MAINTENANCE. It is the same principle like walking throuh long mine field with a map :-) - Once you can get use to it it's quite safe (just don't forget the map ;-)

    The ONLY thing you CAN'T do ANYTHING about is the RESEVE... If you can call it so ...

    Open up the reserve compartment and have a look inside. For those who has seen reserve and freebag before but haven't seen what's inside DHT there might be a nasty surprise. Why? Have a look how the lines are stowed in shock cord loops and tightly locked in by plastic chokers - this is done on purpose to slow down the line deplyment on high speeds. Without it opening reserve on tandem terminal would be a suicide - MR425 hasn't been intentionaly designed as a reserve (as far as I know it used to be a main and it was opening pretty hard and from what I've heard not really reliably) and the kevlar lines used (who knows why?) are transfering full force of the opening shock directly into harness and back to canopy - not the best feature if you need to slow down quickly on short distance (to make the opening bearable the MR425 has to be flat packed and the nose is rolled/folded in - if you don't believe me do a standart reserve packjob and jump it. BUT ON YOUR OWN RISK!!!)

    Anyway back to the PROBLEM NO1: Lines stowed in SHOCK CORD loops choked byPLASTIC CHOKERS on RESERVE deployment bag.
    It it doesn't sound like a major problem consider this:

    Q: Can you get a bag lock on DHT reserve? (Hint - the lines are not free stowed and there is no running loop)
    A: Of course - just like on any other deployment bag where the lines are held in by ruber bands or - in the worst cases - by shock cord. (don't believe me? change your rubber bands on main canopy dbag for shock cord with plastic chokers or just a shock cord. BUT DON'T FORGET - IT IS ON YOUR OWN RISK!!!)

    I'll skip the sharp edges on the plastic chokers (easy to find) and I'll cut to the chase.

    WHAT IS THE POTENTIAL KILLER HERE:

    Imagine this scenario:

    Scenario No1: You have a spinning malfunction, you manage to cutaway easy and just when you are about to deploy the reserve your freakt out customer starts kicking (quite familiar - isn't it?) time is ticking or maybe the RSL already kicked in as well and you are rolling just as the reserve pilotchute leaves your back. Sudenly you find yourself with reserve pilotchute bridle wrapped on some part of your body. What is the possible outcome? (hint: it is a classic horseshoe malfunction the same as on main canopy - the lines are NOT freestowed and there is NO running loop). More likely you end up with heap of mess above your head instead of good canopy

    Scenario 2: What if the reserve bridle or pilotchute will get caught on drogue in tow on hanged up canopy?

    Scenario 3: what if the chokers slow down line deployment and the reserve line will tangle with drougue in tow or canopy hang up?

    Ted and Tom - How can you justify such a HUGE design flaw on reserve system? What is the excuse for this?

  • Quote

    Is this information something that comes from the manufacturer and is taught to TM's using their gear?
    >>>>>
    The line set should be exchanged after 500 - 600 jumps otherwise you can expect bad collapses in turbulence.
    <<<<<



    No, manufacturer recommends to change the line set after 400 jumps as far as I can remember.

    Quote

    One collapse resulting in a student death was on a HOP with fewer than 600 jumps.



    What was the canopy pilot doing prior to canopy collapse? Was the canopy in a straight flight, in a snap turn or was the canopy recovering after radical speed change (radical pulling or releasing brakes?) What was condition of the line set? How experienced was the TM with elliptical canopies and handling turbulence? Was he just flying with his arms up giving up his life to fortune or was he steering the canopy through the turbulence?

    Quote

    HOP you have to fly as like any other modern elliptical canopy
    >>>>>
    How does this benefit the tandem passenger?
    <<<<<


    In general, modern canopies have smooth openings and soft landings and those are the things which the passengers notice most. And if you give them the toggles they can actually fly the canopies by themselves. Perhaps the passengers can benefit from reliability of openings and good gliding ratio so they don't experience off DZ landings so often and you can keep comfortable gaps between exits. Maybe it could be the better penetration in high winds compare to most of other canopies as well. Unfortunately it doesn't come for free. As you go smaller in size you need more skills and knowledge to benefit from advantages which those canopies offer. That's the same for tandem canopies as like for other sport parachutes.