The International Cessna 170 Association

Hello to all. My partner and I just purchased a 1954 170B. Currently N138WW but it has had a bunch of N numbers. I have a few quick questions for the 170 experts. We are both fairly high time taildrager pilots and are very comfortable in the airplane, but want to learn more about our new family member.

1) This aircraft has a Maul tailwheel & clevelands. Really not happy with the tailwheel/ground handling. Breaks very easy and little or no stearing with rudder peddles alone. We are tweaking the springs/chains now but it appears from the reading here that this is a common issue. We would like to possibly switch to the Scott 3200 as many have but I noticed there are many versions. Some with straight spring attach arms and some are bent up at an angle. My question with this is that we noticed that on our airplane there are cable exit guides in the fuse where the later style cables exit for the tail wheel stearing. Currently, the aircraft has the short chain links/springs to the rudder horn. I understand that they changed this in 55 and ran another cable off the rudder cables to the tailwheel arms. My question is that it appears this fuse was late enough in the production line to get the cable exits, but it doesn't have the newer stearing mechanism/cables. Can we change to this newer style? There are even guides in the bulkheads i believe. Also, Scott? or stick with that Maul. Any inputs appreciated.

2) I know I have seen this somewhere on this site as well. Flap notches. The 10degree flap position is placarded but we have no notch. Is this something we can add as well with this serial number. 26189??

Again, thanks for any input.

Neal

goodair wrote:Hello to all. My partner and I just purchased a 1954 170B. Currently N138WW but it has had a bunch of N numbers. I have a few quick questions for the 170 experts. We are both fairly high time taildrager pilots and are very comfortable in the airplane, but want to learn more about our new family member.

1) This aircraft has a Maul tailwheel & clevelands. Really not happy with the tailwheel/ground handling. Breaks very easy and little or no stearing with rudder peddles alone. We are tweaking the springs/chains now but it appears from the reading here that this is a common issue. We would like to possibly switch to the Scott 3200 as many have but I noticed there are many versions. Some with straight spring attach arms and some are bent up at an angle. My question with this is that we noticed that on our airplane there are cable exit guides in the fuse where the later style cables exit for the tail wheel stearing. Currently, the aircraft has the short chain links/springs to the rudder horn. I understand that they changed this in 55 and ran another cable off the rudder cables to the tailwheel arms. My question is that it appears this fuse was late enough in the production line to get the cable exits, but it doesn't have the newer stearing mechanism/cables. Can we change to this newer style? There are even guides in the bulkheads i believe. Also, Scott? or stick with that Maul. Any inputs appreciated.

2) I know I have seen this somewhere on this site as well. Flap notches. The 10degree flap position is placarded but we have no notch. Is this something we can add as well with this serial number. 26189??

Again, thanks for any input.

Neal

Congrats on the purchase Neal!

I feel certain that, unless your fuse was repaired, you probably had a service kit installed to pressurize the tailcone to keep fumes out of the cabin. Gary Friesen can probably pop in here with the Service Kit.

I have a Scott 3200 with a heavy-duty ABW steering arm. I also have an extension on my rudder bellcrank that is decades old and undocumented...likely to get better steering authority out of the tailwheel. I’d say get a new tailwheel from ABW and go from there to keep things sterile.

I don’t recall when the 10° flap ratchet was introduced, but there are a lot of older airplanes that had their ratchet filed by a mechanic, and some replaced with one from the factory. I believe this is just a logbook entry if using a genuine Cessna part.

Thank you! I was wo during if the cable exit was a vent. It is not facing correctly to pressurize the fuse and they are both in line with the tailwheel gorm on each side. Maybe a coincidence. I will have to look at the parts manual and see if the exit is labled.

I am not familiar with ABW for the tailwheel.. who dat?
Thanks again for the input.

Good luck with her, welcome to the association website. Serial number is everything here, does your rear fuselage have the long oval thin cutouts just below the horizontal stab for the rudder cables as well as the lower cutouts for the later style steering cables ?

ABW is Alaskan Bushwheels, a manufacturer of many things that can add fun to airplanes. Look them up online and do a search on their website for "tailwheel"....they have a lot of options.

Congrats and, post pics!!

The most plausible explanation of the extra exit slots are that they where for cables from a wing leveler once installed in the aircraft. This was a not to uncommon. The leveler used cables to move the rudder to level the wing. My 1949 A model has the same slots.

Maule tailwheels in general with the exception of the smallest on a Cub, are horrible. You most certainly will want a Scott 3200. A Scott has better shimmy control, All but one model of Maule, which is pretty rare, have NO shimmy control. This is the advantage of the Scott over Maule. You likely won't find any better steering with the Scott over the Maule unless your Maule is really screwed up. Little to non existent steering control without some differential braking is a "feature" of the 170. Very few steer with rudder alone.

Scott was the original manufacturer. Than became Tyco/Scott. They stopped manufacturing wheels and parts though there are lots of parts available from them. ABW started making parts under PMA for the Scott wheels. Eventually they made every part and then started selling the entire assembly. As far as the FAA is concerned it is a Scott tailwheel but ABW made all the parts.

The upturned control arms are a modification development Scott made for some installations not necessarily a 170. As far as I'm concerned it does not improve the bad Cessna steering chain geometry and does nothing to improve steering. At the same time it reminds me of something that should be on the Star Trek Enterprise, but that's me.

Make sure you have the correct chain control springs, not Maule. Maule springs will cause harm to your airframe.

The !0° degree notch was added at serial 26504 but the ratchet (or a modified one with the extra notch) is approved for all B models. Aircraft after 26504 had a placard with the 10° position. Reproductions only supply the late 10° decal.

Hey thanks to all! The wing leveler explains the cable exits. It was removed years ago but I am sure that is why they are there. Thank you for that.
I will put the Scott on my shopping list. Ouch!

This site is going to be a great asset for us as we learn our new bird. This response is fantastic. I am also restoring a Waco and will post a question on their site with very little response.
Appreciate the help!
Neal

goodair wrote:Hey thanks to all! The wing leveler explains the cable exits. It was removed years ago but I am sure that is why they are there. Thank you for that.
I will put the Scott on my shopping list. Ouch!

This site is going to be a great asset for us as we learn our new bird. This response is fantastic. I am also restoring a Waco and will post a question on their site with very little response.
Appreciate the help!
Neal

Had to replace my 65 year old SCOTT a couple years ago with the Alaska Bush Wheel Assy. Very happy with it. A quality unit and it comes with the beefier steering arm. It will not bend like some of the old straight steering arms. I'm thinking the heavier arms were first used on the L-19 Bird Dog. It was a little pricey at 1000.00, but ya gotta have one. But like Bruce said, if your looking for great steering, it just ain't there.

Thanks again guys. Already got a good start on spending $$:) I just ordered 0510171-1, which is the ratchet for the 10 degree flap position. The supply houses want over 600$ for this part these days from Cessna. OUch. I found one at aTexas salvage yard for 120. Not too bad and easy to install. I know you can file these but this one is legal no questions.

I looked at many airframes before deciding on this one. My partner and I love the polished look, and I have polished a 170B for a customer in the past. Can't really say I am sane for contemplating doing this again, but that is going to be the idea down the road. This airframe was chosen because it has the least amount of interior corrosion I have found, and it has been painted its whole life. No damage history in the logs but there of course is some. There is a patch at the right main gear attach but nothing on the wings at all. I think it will be a good airframe to polish.

One part I am dissapointed in is the front corners of the top cowl. I think every single airframe I looked at had issues here. There are some cracks/repairs on the two corners where the top and bottom fasteners are, outside of the air inlet. Is there a source for the front bowls for these cowls? I see Univair sells the earlier model cowls but doesn't list anything for serial 26189. I can do the weld/grind/polish if I have to. The last one required this and turned out ok, just a lot of work.

I need to look up the image posting proceedures. Thanks again to all!

Bruce's explanation is one of the best ones I've ever read.
One more thing to clarify... the "Maule" tailwheel steering chain springs are "compression springs" instead of the correct "tension" springs. Compression springs have a wire bail which passes thru them and as the springs flex they close up and at full compression behave as solid-steel spacers.... and any further attempt to steer will bend/break/ruin whatever is the weakest link in the rudder control circuit...usually pulley-brackets will be pulled out of their attachments.

The rudder control circuit of 170s have no inter-connect. The only cable-tension is provided by tension springs forward of the rudder pedals, which pull both pedals forward. This is why you can pull BOTH rudders toward the pilot simultaneously (and the rudder cables go completely slack.) This also means that if the pilot or pax STANDS on both rudder pedals simultaneously the system is over-stressed (which usually occurs when straightening one's legs to reach beneath the butt for a seatbelt)**, resulting in the bent tailwheel steering-arm mentioned by Ed. Some early steering arms were made of aluminum and were quickly damaged. Later arms were made of steel. The still heavier-duty Scott 3200A had the up-turned steering arms to accommodate installation on aircraft other than 170s. Some folks have imagined the upturned arms must be an improvement for tailwheel steering purposes but as Bruce correctly pointed out... not so. It has no improvement on the steering. Neither does the attempt Cessna made in '55 with the external steering cabling, which however did add complexity and weight.

WELCOME to the Forums. I hope you'll become a fully-enabled 170 Assoc'n Member by joining up, and then you will also be able to access the Mx Library and Members Intercom and post classifieds in the TradeMart!

** If you're lucky, this is also when your internally rusted seat-back frame snaps and lays you back into the rear seat. The reason this is "lucky" is because 1- you discover you need to rebuild your seat frames and 2- it happened on the ground and not just after takeoff while you're holding onto the yoke and subsequently stall the aircraft at low level. (Which is also why during pre-flight inspection you should set your trim tab wheel at the take-off position and during your walk-around check that the trim tab itself is "faired"... straight back in-line with the right elevator. That way when your seat back fails you can simply let-go of the yoke and the airplane will continue to gently climb at the climb-trimmed airspeed of approx. 70-80 mph.)

Here is the thread that discusses and has pictures of the compression and tension springs.
http://www.cessna170.org/forums/viewtop ... on+springs

HELP! Hey I found an Alaskan bushwheel tailwheel used and just had to get it. It is model ABI 3224. I need to know if I need a spacer for the leaf spring and if so, what size. The airplane is still out east and I think I want to bring this tailwheel with me and swap it out for our trip west. Any info would be appreciated.
I am not sure if all the 170s had the same size rear spring. Again, it has a maul on it now.

Neal

Neal, I'm not sure what main leaf spring you have on with your Maul tail wheel. But the standard main leaf spring for the Scott/ABI 3200 tail wheel on the C-170B is 1 1/2" wide. (Your ABI 3224 is a version of the ABI 3200.) The spacer (170B p/n 0442011-3, which is the same as Scott p/n 3241-3S, L-19 p/n 3241-3S and ABI p/n 3200-ABI-2343-01, adapts the 1 ¾” space in the bracket assembly to receive the 1 ½” wide leaf spring. So it's needed for the standard main leaf spring. I've found that Air Repair p/n 3241-3S is significantly cheaper than the other sources, such as Univair p/n 3241-3S, or Aircraft Spruce p/n 3241-3S or ABI-3243-01. The folks at Air Repair are great to deal with. Here's their contact info:

Air Repair Inc.
920 Airport Service Rd
Cleveland, MS 38732
662-846-0228
https://www.airrepairinc.com/index.html

You need the spacer for the Scott Gene speaks of. Can't recall but for some reason think the Maule does not use a space because it has a 1-1/2" mount.

The way I read George's comments it might seem if you have a Maule tail wheel you have to have the Maule compression springs. You do not. Your aircraft could have the correct Scott spring or an incorrect Scott spring for smaller aircraft such as Cubs and it could have old bed springs. I've seen them all. So look at what you have before just buying new Scott springs at about $35 to find you have decent Scott springs that really hardly wear out. What we are trying to tell you is you don't want the Maule compression spring any longer than you have to.

FYI as I stated most Maule wheels have no shimmy dampening. What shimmy dampening is really is drag on the swivel of the wheel. Scott wheel use sliding plates loaded by spring pressure. On one Maule model they simply drove a bolt into the spindle to add drag. BD Maule being an enterprising, some say genius guy, realized his Maule tail wheel was deficient. He developed a system of two different rate compression springs which he called anti shimmy springs to help correct shimmy. I suppose he thought one spring would not be able to bounce against the tension of the other. Personally I can't see how it would work but he sure sold a lot of them and a lot to Cessna folks with Scott wheels that shimmied despite having a shimmy dampening system. The real reason for shimmy is mounting angle which in the 170 is dictated by the main spring and weight in the AC.

To clarify, here's the springs you DO NOT WANT: And here's the ones you DO WANT PN 3239 heavy duty steering springs: This kit is called "Piper" springs by Aircraft Spruce, but they screwed up... that is a SCOTT part number. They are actually made by Univair under PMA and are ridiculously priced at $71. The entire kit includes the cheap hardware store jack-chain and clips, tho'.