180 Gear vs Lady Legs

[Ryan Smith]

Can someone give me the rundown of the differences between these two gear as it relates to installation on a 170? The gentleman that my father sold our airplane to bought a set of gear legs that he didn't install, but sold with the airplane. Saturday afternoon, I was sitting out at Air Harbor talking to the owner who mentioned that Zenda (new owner) got some "P Ponk" gear legs (nobody seems to understand that P Ponk only makes the bracket, not the gear legs) with the airplane when she bought it. I did a bit of research on the gear legs to be able to identify them, and went over to the airport this afternoon to dig in the parts room. Ed bought 180 gear for the airplane.

Other than being beefier and heavier, the 180 gear are taller, correct? It seems that the few 170s I've seen in person that have 180 gear sit quite a bit taller, all other things being equal. I really liked the landing gear on John Barrett's airplane, but it seems to me that 180 gear would be a little too stiff for a 170, correct? How is the performance/handling of the 180 gear compare to lady legs? Are they worth about the same as a set of lady legs, meaning could one sell a set of 180 gear and get some lady legs and not be out anything?

It's sad to think that my poor baby is being maintained and flown by a group of people that have no knowledge or interest to know anything about her. On the bright side, she is in a hangar now, and there is another 170 (N9206A, 1949 A model) on the field now.

[GAHorn]

The earlier gear on the 170 were interchangeable left/right and had a livelier spring rate than the later "lady leg" gear. Some owners expressed difficulty in learning to land the airplane with such lively gear, particularly wheel-landings because about the time they got the wheels on the ground it would re-bound before they got the yoke forward enough to "stick it" onto the runway. (It has been speculated that many who learned in other airplanes without spring-gear did not develop the skills to land the livelier gear....airplanes such as Aeroncas, Stinsons, Pipers had a much slower/stiffer gear....so the Cessna took some re-learning.) It is felt by some that practice is what is needed ... but that some owners prefer to "buy" their way toward more predictable landings by swapping for lady legs or the 180/185 gear which is much stiffer. And taller. And heavier. And, some say, harder on the airplane.

Those who have it often call it an "upgrade". I do not consider it an upgrade. I consider it an alteration. Depending upon why it was done will color my personal view toward the alteration.

I think the 180/185 gear can be an asset to someone who flies in the outback/boonies where greater prop-to-ground clearance is desired and/or a heavier replacement engine has been installed with a constant speed prop.... but I've not had any difficulty landing the early gear and I wouldn't personally spend any money on a later gear and certainly not a 180/185 gear on a standard airplane even if I occasionally flew out in the boonies.

Our association now owns the STC to perform this alteration.

[Ryan Smith]

The earlier gear on the 170 were interchangeable left/right and had a livelier spring rate than the later "lady leg" gear. Some owners expressed difficulty in learing to land the airplane with such lively gear, particularly wheel-landings because about the time they got the wheels on the ground it would re-bound before they got the yoke forward enough to "stick it" onto the runway. (It has been speculated that many who learned in other airplanes without spring-gear did not develop the skills to land the livelier gear....airplanes such as Aeroncas, Stinsons, Pipers had a much slower/stiffer gear....so the Cessna took some re-learning.) It is felt by some that practice is what is needed ... but that some owners prefer to "buy" their way toward more predictable landings by swapping for lady legs or the 180/185 gear which is much stiffer. And taller. And heavier. And, some say, harder on the airplane.

Those who have it often call it an "upgrade". I do not consider it an upgrade. I consider it an alteration. Depending upon why it was done will color my personal view toward the alteration.

I think the 180/185 gear can be an asset to someone who flies in the outback/boonies where greater prop-to-ground clearance is desired and/or a heavier replacement engine has been installed with a constant speed prop.... but I've not had any difficulty landing the early gear and I wouldn't personally spend any money on a later gear and certainly not a 180/185 gear on a standard airplane even if I occasionally flew out in the boonies.

Our association now owns the STC to perform this alteration.

Do I understand you correctly in that you don't believe that the narrow-ankle (170) gear are better than the earlier, interchangeable gear legs?

I did feel John's airplane easier to land with lady legs, whereas our 170 with the early gear was very springy on asphalt and not as comfortable/predictable when landing on asphalt. I felt right at home with John's airplane. My work around for our airplane was just to land on grass. I was hoping that Ed bought lady legs for our airplane, but was pretty disappointed when I read the 180 serial number stamped on them this afternoon. He replaced the 170 with an earlier 180, so he may have just pulled the gear from that and installed later gear on his new airplane. Sounds like they wouldn't be the best choice for an airplane that's being used for tailwheel checkouts...

He also advertised the airplane as having the P Ponk kit installed, but it was not...it was simply included with the sale. I'm beginning to wonder if the solid axles advertised were installed or simply included with the sale of the airplane as well.

Since I don't own the airplane now, I suppose it's none of my concern. I wish my wife would take my proposal of living in the hangar more seriously instead of insisting on buying a house.

[GAHorn]

...Do I understand you correctly in that you don't believe that the narrow-ankle (170) gear are better than the earlier, interchangeable gear legs?....

No, that is not what I meant to imply.
What I meant was that I personally didn't have the trouble with the earlier gearlegs which some folks talk about. If I owned an airplane with the early legs I wouldn't spend my money buying different gear.

Having said that.... I deliberately shopped for a '53 B-model, and I was pleased to find one subsequent to SN 25612 (after which the lady legs were standard.) I recognize the slower spring rate of the later gear and I appreciate the difference. But if an earlier unmodified B-model had been found which I liked I would not make a gearleg modification.

Similarly, I specifically did not want the later rectangular rear window, or the post '54 tailwheel steering, nor the '56 plastic interior, etc..
But those are all personal choices and no one should feel criticized by me if they prefer those.

[Ryan Smith]

...Do I understand you correctly in that you don't believe that the narrow-ankle (170) gear are better than the earlier, interchangeable gear legs?....

No, that is not what I meant to imply.
What I meant was that I personally didn't have the trouble with the earlier gearlegs which some folks talk about. If I owned an airplane with the early legs I wouldn't spend my money buying different gear.

Having said that.... I deliberately shopped for a '53 B-model, and I was pleased to find one subsequent to SN 25612 (after which the lady legs were standard.) I recognize the slower spring rate of the later gear and I appreciate the difference. But if an earlier unmodified B-model had been found which I liked I would not make a gearleg modification.

Similarly, I specifically did not want the later rectangular rear window, or the post '54 tailwheel steering, nor the '56 plastic interior, etc..
But those are all personal choices and no one should feel criticized by me if they prefer those.

Understood. I like the heater system, gear legs, bullet spinner and tailwheel bracket (which was installed on late 1952 models) of the 1953, but prefer the piano key panel and air box cowling. Luckily, it's possible to retrofit the aforementioned items on a '52.

You're pretty good with facts related to these old birds (red vs. green), so any opinions that I may disagree with are water under the bridge.

[minton]

As I understand it "Lady Legs" were developed as a "softer" gear to improve landing outcomes.
The 180/185 legs are thicker (Stiffer) they accommodate heavier engines in the 170's however being thicker (IF) "P" Ponk kit is installed before hand they (The new legs) won't slip into that slot. You would need to modify the Ponk block and possibly the slot in the outer block to accommodate the new gear leg.
In my opinion the mod is over rated. Improving your landing skills is a better way to go.

[ghostflyer]

My aircraft has the 180/185 gear legs and solid axles but I refuse to add the P Ponk modification . For a wheel landing without the bounce ,I flare out with about 1200rpm and about 10ft off the ground and try to fly it level . Landing have been ok ?? However I have had a few issues with p ponk modification on other aircraft . I watched a aircraft landing in Alaska on a gravel bar and he had a slight cross wind , everything was going well until the left wheel touched down and it dug in as it was very soft gravel . To my horror the leg ripped out but taking the torque box and door pillar out . The torque box was bent and torn and the leg ended up under the aircraft with the l/h wing was bent up at the strut attachment point on the wing . The pilot was injured . He was lucky as we had a radio for assistance . This was the second incident that I have seen a P Ponk rip out the torque box again .If you are going to lose a leg let it break away where MR Cessna designed it to . In a hard hit let all the bits fly off to decrease the energy of the "landing " . Can't comment on flying a 170 with the lady legs as I have never flown one with that type of legs but never had trouble with the heavier legs .

[Ryan Smith]

The current owner wants my set of original wheelpants that were installed on the airplane until the mid-1980s, which leads me to believe that she is going to stick with the 6.00x6 tires. It just seems to be that the combination of the stiffer gear and "harder" tires are a recipe for disaster for an airplane used for training. No solo rentals in the airplane (yet), and I've not heard of any plans to install the gear any time soon. They weren't installed on the airplane during the last annual in February, which leads me to believe that they aren't a high priority.

[bigrenna]

delete

[48RagwingPilot]

I take my '48 C170 with its original, so-called wet noodle, floppy landing gear legs all over the Idaho backcountry and have never had a problem with performance. I think upgrading to a later gear leg is great if you want to spend the money, but for me it's a no-brainer to keep the original. As with most mods, it's a matter of personal preference.

[GAHorn]

Well, as before, I'll second the opinion that Pponk does not cause more damage in a wreck.

Pponk prevents a minor landing mishap from becoming an accident and probably prevents many bad landings from causing any damage at all.

Mr. Cessna did not design the original gear to rip out in any particular way. (In fact he had nothing to do with designing the 170 at all because he'd returned to farming years earlier and he was dead about the time the production line finished.) But that is beside the point.
The point is that if you can tell me how hard you are going to crash I can tell you how much damage you will cause. A cast iron ball will crumble if it hits hard enough.... but it's far more survivable than the sheet tin ball. Pponk will beef up the landing gear attachment and is designed to keep a gear which is loaded moderately sideways from ripping out under loads that an unmodified gear will fail, and if the crash was so severe Pponk equipped airplane is totaled...then so would be the non-equipped airplane.
I can't help but believe those who do not have the Pponk are subconsciously hoping to convince themselves they don't need it, and perhaps they're correct.....If they never have a heavily side-loaded landing.

The lady legs are "stiffer" than the original gear (but certainly not as stiff as 180/185 gear, as those are designed for much heavier airplanes. (I don't care for a truck suspension under my sedan, but then I also don't jack up my pickup truck for the crowds at the tractor-pulls. If I ran my 170 as a workhorse in Alaska I'd probably have a bigger engine, a constant speed prop, and 180/185 gear under it, if I wasn't rich/smart enough to have a C-180 or 185 or DHC-2.)

[GAHorn]

Well, in that case I'd suggest that a 20 mph ground loop might have killed that airplane years earlier if it weren't for Pponk.

EDIT: This comment was in reply to a subsequently-deleted post which included pictures of the damaged area. The deleted post told of a "slow" ground-loop which heavily-damaged a Pponk-equipped airplane, and suggested that when a Pponk equipped airplane fails that it endangers the occupants lower-legs and feet. I do not know how casual observers were able to determine the event occurred at "20 mph".

[DaveF]

Operate your Cessna 170 with confidence, knowing it has been designed with a carefully engineered safety feature in the landing gear system. Dubbed the "Crunch-O-Matic", the landing gear release mechanism activates during low-speed groundloops, safely lowering the airplane to the ground, turning what would have been an airframe-totalling event into an unnecessary airframe-totalling event.

[hilltop170]

Like everything else, the choice is personal and it really doesn't matter to me one way or the other what someone decides. However, the value of the P-Ponk gear mod is impossible to calculate because anytime a gear rips out or collapses due to improper operation, the airplane will most likely be totaled with or without the mod. The repair cost will exceed the value of the plane in the vast majority of cases.

What is impossible to calculate is the times the P-Ponk mod will prevent the gear from failing at all when it would have otherwise without the mod. The stock configuration has one bolt and one nut holding the gear against shear, bending, and tension loads. Bolt heads have broken off and nuts have stripped out when the gear is side-loaded or hits an object which usually causes the gear to collapse. The P-Ponk mod lowers the shear, bending, and tension loads on the bolt, that is about all it does but for me it is enough to justify the installation.

I personally know two guys who have hit objects on takeoff that they did not see that damaged their gearbox with the mod but continued back to the airport for a safe landing and gearbox repair instead of a total. I know three other guys who lost control of their planes and ripped the whole side of the plane out with the mod. But the planes would have failed earlier without the mod anyway.

It can be argued either way but in my opinion, the P-Ponk mod does no harm and may likely save my plane one day. I like them.

[GAHorn]

While those pics are dramatic they do nothing to make a valid comparison versus what the same accident would have looked like without the mod. (The pics would likely be just as ugly.) I guess the occupants DID get out with their legs and feet, heh? Then Pponk didn't hurt them one bit and may have actually prevented that gear from puncturing further into the cabin since it contains the upper end of the leg better.

Ask your insurance company how much they discount your insurance if you have shoulder harnesses. Or fire extinguisher. Or transponder. etc etc But would anyone seriously even consider not having those?

(I'm not saying those comparisons are equivalent to the gear mod,...I'm only poo-pooing the-insurance-company-as-the-decider-argument..... but.... if your answer to the above question is "yes"...then you might reconsider your priorities.) IMO

For those who are curious as to what the mod does, take a look at this link and note that the bolt alone, without the red block, is what ordinarily holds your gear in place. Lose that bolt and lose your airplane: http://pponk.com/landing-gear/#beefup