Wheel Spacings

[asra]

G,day.On a taildragger setup, what about locking the tailwheel andputting go-cart style steering on the mains ?Those setups are pretty simple.Robert DunnMackay. Qld.Growing old is good while it lasts.

[asra]

If it ain't broke......why try to fix itThe setup we have had for ???? years, hasn't let us down yet, it's tried,proovenjust my view.....Russ....A1014 NT....gods country

[asra]

Conventional gear is definitely lighter and better on rough fields than tricycle gear. It could be a real advantage for the 'lead sleds' that are becoming more and more popular. It seems to me that many of the traditional disadvantages of conventional gear simply would not apply to pusher gyroplanes. It will not appreciably limit visibility while taxiing. There shouldn't be any difficulty with control on the rollout, because there is no rollout with a gyro. There should be more than enough rudder authority during the takeoff roll because the rudder is directly in the prop slipstream. Taxiing should be simple with just a fixed, or free-castering, tail wheel and differential braking on the mains.The more I think about it, the better I like it.

[asra]

Russ,"If it ain't broke......why try to fix itThe setup we have had for ???? years, hasn't let us down yet, it's tried,prooven"I can just imagine you sitting around the campfire, grunting at the "wife", saying why cook this, I've been eating it raw for years".I am constantly amazed and saddened, at the intellectual freefall that some people suffer from, when confronted with the possibility of finding an outcome which is distinctly different from that we face on a day to day basis. Would we have the internet if we accepted writing letters as the only medium to communicate? Would we have aeroplanes when we could have simply walked? Would we have had a gyroplane if we accepted that man cannot fly? Of course not.You can sit back and try and pretend that nothing is going on around you in life, but you'll wake up to find the up and coming generation will have left you far behind.Ted

[asra]

Geez.......I hate it when someone out smarts meRuss....A1014 NT....gods country

[asra]

You've got me confused Tim! (not difficulr was it?) First you say that the roll over angle is related to various factors, including track, then you infer the possibility of improving ground stability by widening the track is unlikely to work. Then to confuse me even more you want more training or experience, I thought that was what these people were trying to get without rolling over[]As you said, tail draggers have a directional stability prolem, but don't our current 'four wheelers' go through a brief tail dragger phase on t/o?One of the tail dragger vices appears to at least partially be due to lifting the tail for t/o resulting in a significant swing which has to be anticipated and countered. The Little Wing handling notes specify t/o in the 3 point attitude, so it would be less affected.I recently heard of an experienced Spitfire pilot who got caught out by the swing when attempting t/o in a Griffin powered machine as the engine rotates in the opposite direction to the Merlin, so the swing is also opposite. He apparently 'went bush' in a big way.John EvansThink logically and do things well, think laterally and do things better.

[Tim]

quote:Originally posted by Johnimproving ground stability by widening the track is unlikely to work.I suggested this because Most car drivers go off a corner not because they were doing 1km too fast but because they were doing 20km or 30km too fast. Beginners seem to roll over fairly convincingly rather than just barely rollong over. Your are quite correct though, a wider track is definatey a help, at the expense of "bump steer".quote:Then to confuse me even more you want more training or experience, I thought that was what these people were trying to get without rolling overYes correct. The experience or training level should be such that the correct reactions are instinctive rather than determined. An experienced pilot seems to have all the time in the world to react to adverse situations, whereas a learner has not got enough seconds in a minute to work out which of the primary controls he should be inputting to correct a directional problem, that more often than not, he has created in the first place.quote:don't our current 'four wheelers' go through a brief tail dragger phase on t/o?In my opinion correct again. A tail dragger dragging the tail is normally quite directionally stable. I guess the main problem arises in the critical transition stage between fast taxi and take off, where the mains are normally carrying the bulk (if not all) of the aircraft's weight which is not being supported by the air.BWT, I never knew that the Griffin and the Merlin turned opposite ways. That certainly would have been a handful with 2000hp trying to torque the airframe over. I remember my father telling me that you couldn't firewall the throttle in a Mustang until you reached significient airspeed for fear of hitting a wingtip on the ground (or entering a tight climbing bank with full opposite stick). If you hopped in another aircraft with that kind of torque reversed I imagine that many pilots could get into trouble.Tim McClure

[asra]

On the subject of wheel spacing...Lets say you had a nice widely-space set of main wheels to give you good ground stability. Lets also say you operate out of rough strips, and there is a possibilty of hitting ruts/long grass/shrubs etc that could cause a reasonable amount of drag on just one wheel. Surely the wider the track, the more chance you have of getting screwed around?Anyone with experience like to comment?

[asra]

My turn.......I've noticed that over these many years, the wheel bases have been all around the same width, wot is happening, is more and more are getting SHORTER in their lengths from the nose wheel, to the mains.This I believe contributes a lot to roll overs. Scenario......up on mains,cross wind, oops, nose back on ground, shyte, I'm now goin sideways across the strip, shyte, pull back on stick, things are getting ugly now,let's try everything now, power, stick, anything else........I;m goneIt's ok for an experienced pilot to get away with the short machines, coz he has that feel, the newbies don't, they gota learn it, without the mishapsShort machines , you only have to breath on the pedals to get major responces, if they were longer, it ain't so savage. Also I think all steering should be coupled with pull springs in them, I know it's a pain at times to turn around tite, but if you put it down with the pedals now off setting with the rudder, coz of a x wind, then when your nose hits the deck it will override the pedals and track straightjust my view.....Russ....A1014 NT....gods country

[asra]

Russ, From your response re shortening of length between nose to mains, is it right to assume that by putting the tail feathers further back this will in itself give you a greater moment potential, but that a better solution would be to expand the distance between nose wheel to mains in conjunction with the increased distance of the tail feathers?Ted

[asra]

Drive a short wheel base vehicle over a corrigated road, you better be on the ballDrive long wheel base.......relax and go for the rideNuthin beats length for control, or ease of controlAs to tail feathers going more back, yes, to a point. Definately helps with the horizontal stabilizer bit tho, yes that leverage moment comes in herejust my viewRuss....A1014 NT....gods country

[asra]

Hey Russ, it looks like you're making a case for the tractor gyro with its longer wheelbase[] I'm with you on that spring link to the nosewheel, but I must admit I never had any problem with the nosewheel being centre sprung and billycart steering.You may recall the info in Gyro News about the Victa Gyro, one very interesing feature was its 11'5' track! John Blackler may have had his reasons, Randell Green, the test pilot had to learn to fly a gyro from scratch and do the test flying at the same time!Well put Tim, now I'm unconfused.Lloyd, Tim referred to the steering problem you raised, i.e. bump steer.John EvansThink logically and do things well, think laterally and do things better.

[asra]

so thats what bump steer means...

[asra]

Correction, big brother George, who knows all these things, but doesn't fly anything (I think he knows better) just infomed me that the Merlin and Griffin engines actually rotate in the same direction, but their props spin in opposite directions due to the gearing.Yes Lloyd that's what bump steer is all about. An extreme example of design to minimise it is the skinny front tyre on most dirt bikes, it doesn't get knocked off line as much as a fat one.John EvansThink logically and do things well, think laterally and do things better.

[asra]

Ok if the drag draggers are harder to control on take off phase(the transition) why then are all the tractor types tail draggers??? just a thought..