StuBob wrote:Quick question about the vents. How much finagling are we talking about here? I’ve looked at pulling the old ones out and I don’t see how to do it without removing the struts. And I assume the new ones are shorter?

The stock vent tubes just pull out. Takes a bit of force, but unless they’re badly corroded, no big deal. Some of the later ones hat a small “tit” inside the main tube, to keep the vent tube from sliding out, so you’re pulling hard to get past that. And, before you install the new tube, you’ll want to grind that tit down to prevent cutting the O Ring on the new vent. The new vent is a force fit, and plenty tight.

MTV

gypsywagon wrote:I was out at the plane today and measured the caster angle. It looks dead on to me. So according to the article I should have no shimmy. I was really thinking it was going to be a "negative" angle. but it was not its straight on.
Intrestingly enough there is a line running down the stinger and appears to be an old tailwheel lock. I wander how hard it is to add the lock back. I do not see any instrument in the cabin that would be the tailwheel lock leaver. anyone know where I should be looking in the cabin and where to get the parts to do the tailwheel lock if I wish to go down that rout?

Have I said how much I love flying this plane? Its just so much damn fun. To much for one guy to endure on his own!

On the engine front, its an IO550D, I will go back and look in the operations manual and try and remember if it gave any info on power settings. Not sure it did.

Thanks,
Gypsy

Okay, if your caster angle is good (and should be checked in a for flight weight, as in loaded.......

Then, as Hot rod says, I’d find someone locally who knows tailwheels, pull the tailwheel off the plane, disassemble it, replace any broken parts, lube it, and reassemble it, then reinstall. A “Healthy” properly assembled tailwheel should not shimmy unless badly abused.

Spend some time with the mechanic, taking that tailwheel apart and inspecting it.....it’s not rocket science, but if not properly assembled or if some parts are broke.......

There should be a LOT of tailwheel locking parts laying about, since a lot of them have been removed. First thing, you’ll need to verify that your tailwheel has the locking mechanism. If not, you’re going to need to get a tailwheel that does......bring lots of $$$$.

I agree with Squash that locking tailwheels are nice to have. That said, a lot of 185s have been flown thousands of hours without locking tailwheel. To me, it’s not worth the cost to install one unless you already have the tailwheel itself.

And ABI tailwheels don’t accommodate a locking mechanism, if that tells you anything, since they’re the primary source of tailwheels now.

MTV

First, like everyone else said, congrats on a super sweet find at a super sweet price.

Regarding tailwheel shimmy, if you are still experiencing shimmy after checking everything outlined above, perhaps you are landing too fast (mine will shimmy only if I'm too fast). Try and make all your landings tail low wheel landings, leave the first notch of flaps in on rollout to help lighten the tail, push the yoke forward to help lighten the tail, and use the brakes to help lighten the tail. These things will either keep all the weight off the tail wheel or nearly so and stop the shimmy when landing too fast.

Try and make every landing no matter how long the strip a precision, performance landing. The airplane will be happier, it will serve you well in the backcountry and at high DA strips, people will ask for your autograph, and AOPA will write an article about you. Okay maybe those last two things won't happen.

Here are my 185 Mod threads. Again, congrats.

https://backcountrypilot.org/forum/my-new-skywagon-let-the-mods-begin-21777

https://backcountrypilot.org/forum/let-the-185-mods-begin-again-16499

https://backcountrypilot.org/forum/my-185-project-in-texas-11730

Thanks Barnstormer,
I definitely try and do as many wheel landings as possible and keep it tailwheel up and yes there is usually no shimmy when I am successful. Which I would like to say I am most times. Just looking for ways to get rid of shimmy as well.
I have read your threads many times, but I will go back through them again. Appreciate all the wisdom you share.
Gyspsy

Yeah, wheel landings are great, and I do them every time. But at some point the tail has to come down and we don’t always have the luxury of landing in the perfect winds or weights or on gravel which reduces the risk of occurrence.

Most of the time, shimmy isn’t an issue, and yes, shimmy can be induced by forcing the tail down too soon and with too much force keeping it there with aft yoke in situations when that wasn’t necessary. Keep the tail up. Keep the tailwheel straight. Set it down gently and only when slow.

But that doesn’t always work when on that 1% of the time you are landing on pavement, heavy, in a gusty crosswind and working the rudders such that your tailwheel might be cockeyed when it touches,....it feels like your airframe is coming apart. All that to say that some situations prevent the perfect technique from being employed.

I guess I consider myself lucky that my wagon came with the locking mechanism because it would seem a pain to install (meaning bring $$$ as MTV says). But riding in other people’s wagons that feel like every rivet is shaking loose when the tailwheel shimmies makes me think that I might have ponied up the cash to install one if mine didn’t have it. Easy for me to say that since I don’t actually know how much that would cost. I do know that adding the collar to my assembly for the tail ski was less than $1000 for parts and labor including a service overhaul.

But that doesn’t always work when on that 1% of the time you are landing on pavement, heavy, in a gusty crosswind and working the rudders such that your tailwheel might be cockeyed when it touches,....it feels like your airframe is coming apart. All that to say that some situations prevent the perfect technique from being employed.

I had extensive issues with tailwheel shimmy for years. I agree with the above statement completely. I placed a nice ABW 10 inch fork that helped but I still get the shimmy in the situation mentioned above. I think it is unavoidable because the rudder controls are crossed. I try to straighten the rudder as the plane is slowing down but I still get the shimmy from time to time. I love that it doesn't stop until the plane is literally not moving. On a side note I had to replace my tail stinger in 2016. It broke while I was turning around at Tieton state getting caught in a rut. I believe the years of that violent vibration caused the metal to weaken. I have recently felt more comfortable apply brakes during my wheel landings so the tail comes down a lot slower now.


Josh

One of the problems we all face now with these airplanes is that they are all relatively old, and often well used.

I picked up a 1985 185 with 22 hours total time. I put ~ 3400 hours on that plane, with a little less than half on wheels and or wheel skis. Only time that tailwheel shimmied was with a tailski installed......once. After that, I was VERY careful with the tail with the ski installed. Never had it happen again.

Squash is absolutely right that we don’t always get to choose precisely how our tailwheel touches. That said, I worked that airplane pretty hard and never had it shimmy other than that once with tail ski.

I’ve had other tailwheels shimmy, especially with ski attached. It’s tough to get a proper balance fire and aft with the ski.

But my point is, most of these airplanes have been subjected to some abuse over the years, So is your tail just a tiny bit tweaked, or?

Watch a tailwheel shimmy from outside the plane sometime......I’ve seen it four or five times. It is incredibly violent, and I have to believe that it has the potential to bend things back there.

I’ve experienced some shimmy in every tailwheel airplane I’ve flown much.

Barnstormer offered good advice on prevention. One thing I’d add: When he talked about tail low wheel landing, what he means is touching down at very close to minimum controllable airspeed. That’s how you minimize shimmy.

The vast majority of folks I fly with in these things are landing WAAAAAY too fast.

Slow down prior to touch, and protect that tailwheel. If it shimmies, try to lighten the tail. If that doesn’t work, get on the brakes and stop ASAP.

But, if it shimmies every landing, figure out what’s wrong.

MTV

I have heard a couple of people say that the baby bushwheel is prone to shimmy on pavement. I’ve got no firsthand experience though, so my comment might not be worth much.

I had the baby bush wheel for a few weeks. The only redeeming charecteristic was that it looked super cool. Mine shimmied like crazy, and offered no noticeable improvement otherwise. I got rid of it. It might fit someones mission, but I have yet to hear a good argument for one from someone I trust.

Apologies to the manufacturer, I have plenty of other stuff from them that I like and use.

Brad

There's a C180 in the local mechanic's shop on which the tailwheel is now a sloppy fit on the stinger.
I'd guess that condition could easily induce a tail shimmy.
FWIW the previous owner of my 180 installed a 14" (500x5) XP Mods tailwheel, but told me he replaced it with a 10" because he couldn't eliminate the shimmy

BTW I had my t/w assembly apart yesterday to clean & inspect (hurray, it's annual time!),
the sweet spot for the king pin nut on mine is to tighten it up all the way, then back off 6 flats (one full turn).
at least that's how it was before I disassembled it- guess we'll see if the same recipe still works.

Re locking tailwheel, I don't think ABW offers them, but XP Mods used to.
Tom Anderson, the owner of the former XP Mods, now operates The Landing Gear Works,
he might be able to fix you up with a locking t/w.
https://tlgw.aero/

At work, we have found that the BBW tends to have a lot of shimmy. For our application, we use them anyway, land as slow as possible, and stop as quickly as possible to minimize any opportunity for shimmy. We use them because for many of the beach locations we frequent, the smaller tailwheels make ground handling very difficult because they dig in and we end up needed much higher power settings for simple taxi operations in the backcountry, which we are not fond of. The flotation of the BBW on soft sand is pretty substantial compared to the stock offerings and that makes it worthwhile. But we are very aggressive in our efforts to prevent shimmy when we land on the pavement because, as previously mentioned, it can really damage the plane.

There is a time and place for wheel landings AND 3-point. You should be proficient in both.

I've never heard a good argument to not have a TW lock. You're flying a $100-200K airplane. It's an expensive piece of equipment. Why skimp?

AEROPOD wrote:There is a time and place for wheel landings AND 3-point. You should be proficient in both.

I've never heard a good argument to not have a TW lock. You're flying a $100-200K airplane. It's an expensive piece of equipment. Why skimp?

Agreed on three points and wheel landings, both have their place.

As to reasons for operating without t/w lock, try this one:

You’re flying an airplane for hire. The owner for whatever reason chose to remove tailwheel lock or bought airplane without tailwheel lock.

Employer expects you to be able to fly the damn thing, with or without a tailwheel lock, and under pretty much any reasonable circumstances.

Hell, I’d been flying 185s for years before I even knew some had tailwheel locks, duh.

MTV

What he said. Been flying them for work for years. Have not yet flown one that has a tailwheel lock installed.


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Troy Hamon wrote:What he said. Been flying them for work for years. Have not yet flown one that has a tailwheel lock installed.


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mtv wrote:

AEROPOD wrote:There is a time and place for wheel landings AND 3-point. You should be proficient in both.

I've never heard a good argument to not have a TW lock. You're flying a $100-200K airplane. It's an expensive piece of equipment. Why skimp?

Agreed on three points and wheel landings, both have their place.

As to reasons for operating without t/w lock, try this one:

You’re flying an airplane for hire. The owner for whatever reason chose to remove tailwheel lock or bought airplane without tailwheel lock.

Employer expects you to be able to fly the damn thing, with or without a tailwheel lock, and under pretty much any reasonable circumstances.

Hell, I’d been flying 185s for years before I even knew some had tailwheel locks, duh.

MTV

Sweet, lets beat this horse again...

Not trying to stir the pot, but is a tailwheel lock mandatory with a tail ski?

Have penetration skis, don’t have a wheel tail ski yet, wonder if I dare try without one.

Pinecone wrote:Not trying to stir the pot, but is a tailwheel lock mandatory with a tail ski?

Have penetration skis, don’t have a wheel tail ski yet, wonder if I dare try without one.

First question you should ask is “Do I need a tailski?” I’m a big fan of tail skis on a 185, but it really depends on where you’re planning to land that plane. Are you going to well groomed (packed) strips? Probably don’t need the tail ski.

Going to pioneer landing sites in potentially deep snow? I’d definitely use a tail ski. Again, talking 185 here, though again I’m a fan of tail skis.

With that answered, do you HAVE to use a locking tailwheel with a tail ski? I guess not, in my opinion. I ran 185s on retractable skis for a number of winters with a tailski installed and no locking mechanism on the tailwheel.

It helped that the airport where those planes were based were groomed for skis, which reduces the probability of shimmy. But, I also landed many times on paved surfaces.

It’s quite possible to avoid shimmy by using good technique, mostly, anyway.

Me, I wouldn’t worry about it.

MTV

Pinecone wrote:Not trying to stir the pot, but is a tailwheel lock mandatory with a tail ski?

Have penetration skis, don’t have a wheel tail ski yet, wonder if I dare try without one.

First question you should ask is “Do I need a tailski?” I’m a big fan of tail skis on a 185, but it really depends on where you’re planning to land that plane. Are you going to well groomed (packed) strips? Probably don’t need the tail ski.

Going to pioneer landing sites in potentially deep snow? I’d definitely use a tail ski. Again, talking 185 here, though again I’m a fan of tail skis.

With that answered, do you HAVE to use a locking tailwheel with a tail ski? I guess not, in my opinion. I ran 185s on retractable skis for a number of winters with a tailski installed and no locking mechanism on the tailwheel.

It helped that the airport where those planes were based were groomed for skis, which reduces the probability of shimmy. But, I also landed many times on paved surfaces.

It’s quite possible to avoid shimmy by using good technique, mostly, anyway.

Me, I wouldn’t worry about it.

MTV

Thanks MTV. Where I plan to go, I’m not expecting to see any other tracks. I just checked weather statistics and I can expect up to 6’ accumulation by the time March rolls around. My recollection is that there isn’t much wind packing, or melt to solidify the snow through the winter. It could be all loose pack when I get there. There’s a snowmobile stashed there if I need it to pack a runway to get out. I’ll have supplies for a week and a cabin. Helicopter is stationed 40 miles away for worst case. I’ll be looking for places in Southern Alberta to practise before I head north.

Pinecone wrote:Thanks MTV. Where I plan to go, I’m not expecting to see any other tracks. I just checked weather statistics and I can expect up to 6’ accumulation by the time March rolls around. My recollection is that there isn’t much wind packing, or melt to solidify the snow through the winter. It could be all loose pack when I get there. There’s a snowmobile stashed there if I need it to pack a runway to get out. I’ll have supplies for a week and a cabin. Helicopter is stationed 40 miles away for worst case. I’ll be looking for places in Southern Alberta to practise before I head north.

Take lots of cold weather camping gear. If (when) you get stuck, set up camp first, THEN try to get unstuck. I’ve got a few stories due to 185s on skis.

But, it’s part of the deal. Just be prepared.

MTV