48' 170 wing questions

[Flemswert]

Hey guys I have a 48' 170 rag wing and will be recovering it this winter. While I'm in there I will be replacing the Grimes landing light with leading edge landing lights, adding a 4th fuel tank as well as changing my filler neck (probably) to the newer 170 style cap. I am wondering if the wing shares an airfoil with the 140 or any other aircraft? I am working on getting approval for a sportsman stol kit and some other stuff but wanting to verify the wing details for research purposes. I'm looking at a few other options as well but depending what the FAA says I need to do for approval I'll let y'all know about it later.

On a different note has anyone played with modifying the flaps? Maybe making them a few inches bigger or doing a gurney on the end? Im looking for potential options of making them more useful and experimenting with making the wing a better overall design. Any ideas would be great!

[n2582d]

Flemswert,
Welcome to the Association! You sound ambitious! I'm sure we'd all love to see photos of your work in progress.

Comparing the part numbers for ribs between the C-120, 140, and 170 one finds that in fig. 3 of both IPC's the C-120 and 140 use 3 ribs with a p/n of 0422148 and the 170 uses 6 of those same ribs. Rib p/n 0422212 is also used in all three models; each left wing uses 2 of them. So I think one can safely say that the airfoil is the same for the 120, 140, and 1948 170.

Bruce has done an incredible amount of work downloading stacks of 337 field approval forms. You'll find them here. Some of the links to these files no longer work there but the links to the same files do seem to work by going to our Home Page > Members Area > TIC170A Document Library > Link to copies of STC's and 337s.

I've updated how to find free Cessna IPC's here

Regarding wing modifications, it sounds like you need to talk with Milne "CC" Pocock.

Slats-1000w.jpg

[Flemswert]

Thanks! I live in Alaska and everyone I know has done some cool stuff with their cubs, pacers and 170B's. The 48 170 is a great and very capable aircraft. IMO pilot skill will get you in and out of anywhere a 170b will take you. With Airworx making the o-300 have some power potential, not being able to put an o-360 on the front isn't as big of a deal. I am just doing preliminary research to see how easy / hard it will be to do some of the things I want.


I'm guessing there aren't a lot of people who may have experience in this but if you had to pick slats or a stol cuff would there be a preference? Slower stol speed being the goal.

[n2582d]

I'm guessing there aren't a lot of people who may have experience in this but if you had to pick slats or a stol cuff would there be a preference? Slower stol speed being the goal.

Contrair! There's a lot of guys here with experience on slat-equipped aircraft ... mostly over 100,000 lb. MTOW. I've got a couple of years experience flying an H-295. Most capable STOL aircraft I've ever flown. But the slats are part of the wing design, not an add-on appendage. With either fixed slats like Pocock's or a leading edge cuff I think, without extensive and expensive flight testing, you'll be forced to fly it in the experimental exhibition category. As far as I know, there are no LE cuffs (Sportsman, Bush, Horton, Robertson) STC'ed for the 1948 C-170. The leading edge profile is different on the straight 170 and the subsequent models so, at the very least, one would have to replace the leading edge foam blocks that mount between the existing leading edge and the new STOL cuff. There are also no STOL kits that I'm aware of for the C-120/C140 that could be modified for the '48 C-170. Vortex generators are available for the '48 C-170.

Looking at the most recent results for the Valdez light touring STOL competition, it appears you need to be considering adding a nosewheel. Did Met-Co-Aire offer that for the '48 model?

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Seriously, I think the best thing you could do on a '48 170 to improve takeoff and landing distance -- other than an 80" prop -- would be to make it as light as possible. Think "how can I reduce weight?" rather than what needs to be added to improve performance. Oratex fabric, polished aluminum, small tires, back and right seat removed, right control yoke and rudders removed, no interior, titanium gear and axles (most improvement here comes from a lighter wallet), Scott model 3-24B tailwheel, lightweight or no starter, B&C lightweight alternator, EarthX battery, electronic ignition, no venturi tubes or vacuum pump, min. radios, electronic flight and engine instrumentation, min. fuel, etc.

[Flemswert]

Thanks! I live in Alaska and know most of those guys. Spence is a phenomenal pilot and that thing is pretty nuts! My goal isn't to be the most stol capable aircraft at an competition, but real world off airport stuff. I have 31" ABW, T3 suspension and a baby bushwheel and that won't be changing. Getting lighter is key for sure, I currently fly have no interior, rear seat removed and run an 82" Sterna Ground adjustable prop. With the McCauley 7653 prop, and my current setup I weighed 1354# empty. I am going to me removing some weight this winter but there's not a TON I can do that hasn't been done there.

Going experimental isn't out of my options but I'm trying to weigh them before making a decision. There are companies that can make stol cuffs and slats for my wing but like you said, there are not any STC'd.

I didn't mean people didn't have experience with slats but there probably weren't a lot of people with experience on the 170 specifically.

Thanks for all the input, it's a heavy decision to make and I'm trying to be thorough!