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  • #16
    Last edited by RossM; 01-11-2017, 06:12 AM.
    Remember: no matter where you go, there you are

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    • #17
      hello ross oh mate of mine. dobber. interesting though. probably not just one bump or hole to hit , it could be towed behind a car , a simple axle to keep it level but be able have the weight on it . and let it float as if it was on the front of the gyro. this way one could try all the problems of not only taking off take " speed over rough ground " which our little wheels cop a flogging at before they lift off. but also landings . if you need anything there alan [ this is probably a bit further down the track than you wanted , but thanks to ross, let me know , probably heaps of stuff laying around for the tow design ],
      I had taken some photos of my front wheel set up which works very well , also over rough ground also with a fat pilot on a heavy gyro. my strut is 20 degrees . it's a bit of a knock off design of Owen Dahl's. more spring travel both up and a bit down , more up than down obviously. while still having 1:1 control of the front wheel [ not effected by travel of the front wheel strut ]

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      • #18
        the 20 degrees was a good angle on the above photo. on the 2 seater I have been doing for ever I thought more was better and went to 25 degrees but I'm not sure that will be better. my idea was that with the extra weight of a 2 people the increased angle takes / absorbes the bumps up the slide working on the spring. does that makes sense. it did in my head .

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        • #19
          Originally posted by Waddles View Post
          We are trying to determine if there have ever been any nose wheel strut failures in gyros. If you know of one or more, please post here or send me a PM.

          This is not a witch hunt, merely an attempt to determine if we need to specify a minimum fore/aft load on the nose wheel assembly.

          I can't recall any problems, but my memory is no longer what it used to be.

          Thanks.

          Regards,

          Waddles.

          Only failure I've even seen was on a compliant factory built two seater, at the last nationals.

          do I think there should be specifications for structural integrity of the nose wheel... Yep!

          But... only on compliant Two seaters! Or Factory built Gyro's

          The basic category gyro homebuilt regulations, should be kept simple and easy for the home builder that is never going to fly out of licenced aerodromes or in regulated airspace, I remember when it was the basic paperwork, two pages. Now it's 10 -12 pages plus the original two pages, then you flight test it, and then get it signed off again, plus a flight manual...,... ahhhh

          as you can tell fustration... I've finished a gyro 3 months ago but gotta get all this bullshit paperwork done before it can legally fly.

          thats my rant anyways....

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          • #20
            I think we need to remember and think about our ASRA members that have to go to crash scenes and courts. I wouldn't be any good at it , so I am happy to leave it to others and pay my way in membership fees, but also respect the ones that do inspect accidents that there is a certain level of safety, not just for ASRA members that inspect the accidents but also their family and loved ones.
            I'm not a believer in the saying " he died doing what he loved " . to actually think that anyone would be happy dying "because they were flying" because they loved it, is crap. to actually think that their bodies are pulled from a wreck and their families would be happy their loved one died that way was ok, is also crap.
            so to have a level of safety in certain areas for everyone concerned is fine by me. I also respect the people that volunteer their time to see this through.
            that is the end of my rant, and i'll let Allan have his thread back.

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            • #21
              Your point is well made Tony. I've had to be involved in investigating several fatal accidents myself, never a pleasant thing to do. In all fairness though, of the many nose wheel failures that I am aware of, I don't recall anyone being hurt.
              Another thing worth considering is that I am aware of just as many main wheel failures. While we have a drop-test for compliant gyros we have no test for lateral integrity. If we can work out a system for testing nose wheels we may be able to use the same tests for mains.

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              • #22

                We are aware that it would be possible to make up a test rig and test to destruction, then place some operational limit on the use of the specific assembly. The problem is that we don't really want to mandate this type of testing. It would be expensive, time consuming and probably not worth the effort. Although, from his post, Trent would really love us to mandate something like that!!!! (Not).

                The thinking is that if the energy from an impact on the nose wheel assembly could be calculated, then it would be possible to take the worst case scenario (say a gyro at MTOW and a speed of say 40 kts), calculate the strength required to resist a failure and apply the published safety factors. Tim has mentioned this already at 1.5 for basic gyros. This is a more efficient way of doing it we think. Of course, one could go silly and use ridiculous figures for the calculations, but in reality, a pilot should not have the nose wheel still on the ground above 40 kts. There may already be a method of establishing the required load factor on a nose wheel assembly and the research into this possibility continues.

                So. Keep the comments coming. It's good to see some discussion on this medium

                Regards,

                Waddles.
                Waddles

                In aviation, the only stupid question is the one you don't ask!

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                • #23
                  The problem If there really is a problem out there of nose wheel failures, Is when are they showing the failure is it the first 5 hours showing a design weakness or is it over 100 - 200 hours showing a repetitive fatigue failure. I can understand why load testing on intial rego is a good idea to insure it will be all okay for the first takeoff and landing but after that anything can still fail if it's mistreated or poorly engineered over time....
                  Goes for all components, Poor SamL's accident is a sad example...

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                  • #24
                    Did some quick searching of England's BCAR's for gyroplanes since they put such onerous restrictions on building gyroplanes, attached is their requirements for thought. Still think that education is better than making everything in the world rules and regulations....

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                    • #25
                      nose wheel shouldn't be on the ground at 40 knots, definitely right if the balancing is under control but it can get popped backed down on the strip if I'm a having an off day.
                      and of course flying straight and level doesn't count until your in the air actually flying Justin so I'm still in the clear matttteeyyyyyy !

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                      • #26
                        Thanks Trent,

                        The BCAR-T stuff looks interesting, although I suspect that these loads will suffice for tarmac and smooth runway ops. Whether they would stand up under out rough conditions remains to be seen. It is a good starting point and maybe one for comparisons if something else comes up.

                        Just to be clear; there is no intention to mandate any sort of testing or mods for currently registered gyros, be they basic or compliant. If a consensus is reached, the construction standards will be modified and it will be up to the builder to attest that the nose wheel assembly meets to specified load via the F22 or F24 as applicable.

                        When the failure occurs may not be indicative of a design fault or a fatigue failure, although the fatigue failure is generally easy to detect. The issue appears to be when the gyro is operating over rough ground or encounters a significant depression in the ground. A rabbit hole would be an extreme depression in the ground! I guess that a design that is satisfactory for smooth even surfaces may not be adequate for rough surfaces and we are under some obligation to take into account the worst case scenario, because that's what we have in Oz.

                        Thanks again.

                        Waddles.
                        Waddles

                        In aviation, the only stupid question is the one you don't ask!

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                        • #27
                          Hi Chook, the M24 has a door sensor with warning light and also will not display the rotor tacho if the doors are not closed properly.

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                          • chook
                            chook commented
                            Editing a comment
                            Thanks Jeff - yep saw one today but I never managed to get some pics. The pin in the Xenon goes into the surrounding rib but doesn't penetrate to the other side so I will have to design something which doesn't further impact the rib strength.

                            Regards..........Chook.

                        • #28
                          I designed my nose wheel the 'old fashioned' way by having a ralatively low cabin thus allowing a short nose wheel stem and a 'caster back' configuration so it is still stearable even with loss of control rod. If the complete assembly breaks off the nose cone doesn't drop too far and one may be able to 'bush improvise' a wooden skid to get home. Call me 'old fashion' I don't mind. Besides, I want to fly until I'm 100 (Cronalogicaly) and if the cabins too high I may in the future break my brittle neck getting out.

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                          • #29
                            you ticked all the boxes there max, I wouldn't of expected anything less from you .. the low entry exit is appealing in my older age getting off after a fly I feel stiff as . .

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                            • #30
                              The BCAR's seem like a good starting point, however Einstein once said "If you can't explain something simple enough for your subject to understand, then you do not understand it yourself" (or words exactly to that effect).
                              I get the impression that the person who wrote this did not fully understand all the implications of the variable loads on a nose wheel. I can't help feeling that one of the experienced and practical gyroplaners should be able to put something together in a simpler and easier to understand draft.
                              I believe Chuck Beaty would be a good one to try. There are some who believe that he is past his use-by date but make no mistake about it, Chuck has probably forgotten more than his critics will ever know.

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