Gyro Accident Tasmania

[Des Garvin]

Now I"m just the party pooper here!!!!! That stainless cable is going to wear shyte out of that ali due to viberation unless you put nylon tubing through the holes that the stainless passes through, peroid. Cheers party pooper Des.

[asra]

Peace of mind untill the very rare event of a control failure and then perhaps not worth a cracker. I think I"ll just stick to the locktite and nyloc lock nuts like I have for years untill I do a rebuild. I"ve already got redundancy in the torque tube and crossarm and when I rebuild I"ll incorporate full redundancy in the control rod assembly.

[Russell]

My 2 bobs.............rod ends have served us well since day one, only recently have we had some concerns..........."builders" opting for a cheap type.........not installed correctly.......not preflited for security.........on and on...on several occassions i have noted that on full "roll" ( stick full left or right ) that the rod end through bolt is binding...........jammed, once i noted that removing that through bolt allowed the head to "roll even further" to it"s full roll position. Further more, if that head "roll" setting is set, and the adjustments to the pushrods / rodends, is set at zero slop, after general wear and tare in the head bushings etc, then extra stress is transmitted to those rod ends etc. The majority of flyers "trailer" their machines, the shake rattle and roll coming with that is dead set problematic for a machine built to fly. ( shock loads trailering are huge ) and more exact inspections / replacements are required. We check our oils more carefully than other more important issues in the machine.These "redundancy strap" thingoes............i"ve never had to control a gyro that was not fully connected to my control stick, but i"m pretty sure, if i had everything floating about up there .....ie.......bound by "straps" i think any control would be zero???.........maybe not ???Let"s reflect back 30 plus yrs...........rod ends have served us well. We are not doing "our thing" properly.just my view............

[Des Garvin]

Hi All,
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[Brian]

I dont know much but I just wonder why it is that the Rosco machines seemingly have so little technical problems and given that there are plenty of them out there racking up a lot of hours, mainly outback working in all types of weather off mostly rougher strips.I"m with you Des on that cable, would be better inside some sort of nylon tubing and then I"m not dure either should a rod end break just how much that cable is going to help, obviously a lot better than nothing.Trailering a gyro is just plain hard on a gyro, no matter how you tie it down.I do a lot of k"s with my gyro in the back of the Nissan and despite the Nissan riding pretty well, the gyro still gets moved about. I restrain the main wheels and nose wheel and leave the gyro to move around on its suspension.

[Greg Mitchell]

Allan, PC is playing up, so here is a reduced pic of his gyro with spliced push rod.Mitch.

[Ken Watson]

Sam, it cant come undone if they are both right hand thread. If you are concerned put an extra lock nut on to use up the unused thread and nothing will move. As for that strap. come on its not worth a pinch of salt. Put on 3/8th rod ends and not 5/16-easy fix. If these are the solutions put up and supported by TA"s then I want to refill out my CASA survey. Does anyone out there have any common practical ability in engineering.This is the sort of politically correct **** that politicians dribble out to solve a problem.This may have been an accident purely caused by human error.If so no solution is necessary.Speculation may strike fear in everyone unnecessarily and provide us with a solution that is nothing more than a false sense of security. By the way I have wooden skyhooks for sale that will hold on to the nearest cloud for just $90. Pretty useless on a clear day but otherwise guaranteed.I only have a few so get in quick. The gullible will be served first. Ken

[asra]

Well put Ken.As for rod ends and stuff I work on the theory that anything mechanical can break down and all humans make mistakes even if they are just little ones. Like getting back from four hours mustering and finding a safety clip in my pocket looking up to see the castle nut on the teeter bolt finger tight. Looks like everybody has a bit of a set on rodends as though they are the only parts that could possibly fail. It might not be for everyone but if I can set up the controls so the machine wont spit the dummy if something gives when I"m pulling it around hard then thats the way I"ll go. I wont be racing out to do it but I can"t see a problem with having redundancy in an aircraft.

[tonydenton]

gents , what does the term "redundancy" mean here in these posts ?????

[asra]

Redundancy - having a backup system or having it designed in such a way that if a component fails the aircraft can continue to function. Thats what I"m using the word for anyway.What it means in practical terms is that instead of going splat into the dirt you keep flying and when you land you say awe **** I forgot to tighten that up.

[Greg Mitchell]

wikipedia......In engineering, redundancy is the duplication of critical components of a system with the intention of increasing reliability of the system, usually in the case of a backup or fail-safe.In many safety-critical systems, such as fly-by-wire and hydraulic systems in aircraft, some parts of the control system may be triplicated.[1] An error in one component may then be out-voted by the other two. In a triply redundant system, the system has three sub components, all three of which must fail before the system fails. Since each one rarely fails, and the sub components are expected to fail independently, the probability of all three failing is calculated to be extremely small.Anyway, I"m personally a lover of a very light basic gyro. Now I"m in need of assistance to spin up my blades, I have a heavier, though more powerfull gyro than before. Not a big fan of adding weight personally, or to the airframe itself...However, it looks like Ken will be re-doing his suvey.I do believe Birdy has had redundant straps attached to his feral for some years. They may be somewhat different but I believe, intended to do the same job in the event a rod end fails.There has been a thread running on the US forum since Michael Howard passed away, detailing just such "fixes" and contributed to by some Aussies.Personally, I flew my Monarch with my MLS pre-rotator spinning to 220-250 rrpm doing regular short field takeoffs and having fun cranking turns etc.So much has been said here about this or that breaking, that frankly, have not convinced me one way or another.My views on what transpired are pretty well set in my mind now and had been so, before the Nationals began. Again speculation.And I still think they (the straps) are ugly and a tad to long but weigh next to nothing and if people on the ASRA Board and some TA"s and INSTRUCTORS think it couldn"t hurt and just might provide some "redundancy" or enough cntrol input to get a craft back on the ground, then, I"m putting them on my ship.Here is some interesting reading and an old pic of Allan flying his first Monarch variant.Fly Safe.Mitch.

[Greg Mitchell]

I would likely want to have a closer coupled set of straps. I think here is far to much play allowed for in the currently posted setup.Fly Safe.Mitch.

[tonydenton]

i have been wanting to say or ask for awhile now about alans full version of his coming down to be printed in the mag. once again it makes interesting reading and not every body gets on here, also because of your day job al we get a more professional blurb about it .

[Waddles]

Des,Sorry Mate. Ever since I"ve had my F truck, the gyros are tied down using truckers straps about 2" wide that are attached to the tray in front of the mains. They then pass over the wheels, through U bolts in the tray, then are tightened using ratchets attached to the tray. The nosewheel is strapped from above the spring suspension to the tray. No other tie downs are used. The main suspension is allowed to move as it wishes in response to uneven surfaces. The control column was strapped loosely with 1" webbing and buckles about mid travel. I can see that this would allow the MLS system to bounce around over bumps etc. We have already devised a system that "locks" the head using rubber stops on the head stops under the torque tube. It may be better still to remove the controls rods during transit and make sure someone else checks them for security and movement before flight.Tony,No problems with printing as requested in the GN. The Editor is free to use this if he wishes.Ken,I think I mentioned "speculation" earlier in the thread. That"s what all the discussion is about. However, I think it is healthy and may lead to better practices in the future.Pilot error is ALWAYS considered in investigations. I freely admit that it could have been my fault either directly or indirectly. I have never shied away from wearing the can if necessary.Rod Ends ....... there is no history of breakages at all unless they have been involved in previous accidents. I think Tim Mac did tests on 5/16" rod ends by bending in a vice. The picture I saw had the shank bent at 90 degrees with no signs of fracture at all. Re fitting, ASRA released an AD earlier this year aimed at eliminating the possibility of in-flight dislodgement of rod ends. 3/8" rodends? Use them by all means but it won"t help if they are not secured properly. Any more questions or information wanted, keep them coming. I have nothing to hide. (After 20 minutes in the 15 degree Tamar River, I had nothing to show!!!!)Regards,Waddles.

[asra]

OK there seems to be some misinformation about why I suggested some sort of redundancy for the Butterfly gyros. Firstly I have no real problem with 5/16 rod ends,they have been used for years without any real problems.That doesn"t mean they are infallible. The strap shown in the photo would easily be capable of supporting the weight of the whole gyro,or two for that matter. It is in place as a "last resort" and I didnt just slap something together as a knee jerk reaction.I have tested a more rudimentary version on a gyro I have here and with rods ends disconnected you still have a good degree of control relying on cables alone on BOTH top control pivots.The amount of vibration that can occur with heavy use of the MLS pre rotator Leeds me to my belief that a rod end or pushrod has failed on Allan"s gyro,most likely the left hand one that had the splice halfway down. That was the only Butterfly gyro fitted with that type of pushrod system and the "strap" mod wouldn"t have been any use if the pushrod has let go at the splice.I"m sure IF a rod end is the cause of Allan"s control failure he would have been a lot happier with a small stainless steel strap holding things together.