SonexBuilders.net

Just wondering out loud...sorta...about anyone who has installed a regular, spring coupled, full castering tailwheel assembly instead of the Sonex direct drive design? I was signed off as conventional gear pilot, but still feel that I am just a second class one because of the direct drive Sonex, which is the only TW aircraft I have ever flown. i an most definately not disappointed with the design, but this spring I will be transitioning to hard surface operations. Some have replaced the hard rubber wheel with a pnumatic one, after indicating the hard rubber one tends to skip sideways much easier than the pneumatic tire. this sort of makes me concerned prior to my first hard surface event. And then there is the full castering TW modification, but I am not sure I want to do that just yet, if ever.

Does anyone have experience with the pnumatic tire, and/or the full castering TW mod? That you would want to tell about, maybe!!?

As always, thanks in advance!

Hi Joe, for a start, there is no difficulty using the hard rubber wheel on sealed runways, but all the combinations you have mentioned have been tried in Australia except maybe the spring coupling because you would need to make two sided steering arrangement for the bottom of the rudder.

I have been using a pneumatic tire for about 6 years and much prefer that to the hard wheel. It is quiet and grips better. The trade off is extra maintenance.
Brian Ham, Sonex with Jab 3300, has a solid rubber full castering tail wheel. I'm pretty sure it still uses a solid steering strut. He has been flying his Sonex for about 5 years and appears happy with the arrangement.
Steve Woodham, Sonex 892, has built a full castering pneumatic tail wheel. Steve is a regular contributor here and is pretty likely to add his voice. The only disadvantage I can think of is that you would be more likely to land tail wheel first because of the extra height needed for the castering mechanism. On the plus side, taxiing visibility would be improved.

Peter

The side skidding is due to crosswinds pushing the tail. With a full castering tailwheel that would not happen. The tail wheel would break free and the tail would swing. If brake and rudder are not immediately applied you are headed for an excursion towards the edge of the runway or off runway; or worse a full fledged ground loop. I learned tail wheel in a Luscombe 8A, with too much crosswind and not enough rudder it was easy to loose directional control. That meant much "dancing" on the rudder pedals on roll out. The only advantage to a full castering tail wheel is the tight steering on the ground if you have differential braking . I find the directional control from the plans design much easier than a castering type tail wheel. My 2 cents worth.

Also learned to fly in a Luscomb 8A and that is the reason I put differential (hydraulic disk) toe brakes in mine, back when Sonex was telling all that replacing their mechanical drum brakes would put the plane over on its nose, and that Luscomb experience is also why I am sticking with the direct connected steerable tail wheel.

David A. Sonex TD

I don't see adding springs bringing any improvement to ground loop tendencies or sideways skipping. The primary benefit of a spring coupled full castering tailwheel is the ability to make tight turns.

The only down side to the standard Sonex direct coupled tailwheel in my opinion is the large turning circle (yes I had to get out once and turn the plane around on a narrow grass strip} and that is a minor disadvantage compared to all the advantages in my opinion. I am no tailwheel expert (500 hrs) but I have found the Sonex to be the easiest of all the tailwheel aircraft I have flown to land. Even the small hard rubber 4" wheel works fine on hard or soft surfaces its just so damn noisey.
I fitted one of Peter Ansons 6" pneumatic wheels, just so much better. I did have one scare with the pneumatic wheel due to a puncture but even then I still had control. I do not like full swiveling tailwheels, they seem to have a mind of their own.

Flyboy accessories has sonex tailwheel kits that will allow a full castering assembly. I have one and it works great with differential braking.

https://www.flyboyaccessories.com/RV-an ... ts-s/1.htm

Wel, these are some great replys!Thanks to all. I will forge ahead with what I have, a 6 in hard rubber tail wheel, and after confirmation of a fix for a squelch problem on the com radio, I will, as they say, endeavor to continue! and if I can get the last 17 hours flown off the phase one without any problems, maybe I shall see some of you in fayetteville in June!

Joe, What area were you able to get to fly off phase 1?

H Joe

As far 99 percent of the normal flying activities go, That is taxying ,take off,landing. The original sonex wheel does a fine job. I did about 800 landings on the same 4" tailwheel. The thing is still not worn out and is in my spares box.

I made a steerable breakaway full castoring tailwheel using a Peter Anson designed 6" aluminium wheel and pneumatic tires. I love it. Until it breaks free at full rudder deflection it feels just the same as the original tailwheel.

The advantages of what I have now are only. Less noise, greater maneuverability both while taxying, and pushing it around the hanger. It does lift the tail up a bit but that improves the visibility. As far as touching down tail first, I used to do that all the time with the original 4" wheel anyway. The only disadvantage I have found is more maintenance is required.

I had spring steering on a Sonerai I didnt mind that either. I dont know how that would work on a sonex with the rudder hot being hinged on centreline.

Steve
Sonex 892