The International Cessna^® 170 Association

I've been able to determine that the 175 wing will bolt right on to a 170B and offer 10 gallons more gas. Has anyone ever done this??? I am rebuilding a B model that went on its back so it needs a set of wings, I figured why not upgrade at the same time. Thanks for the help.

T

You're correct in that C-175 wings will bolt right up on a C-170B. The bite is that it requires a 337 "one time" STC which is now , for all practical purposes, impossible to get.

The TIC170A headquarters has numerous copies of this modification for examples. You can order copies from them.

If you're successful in accomplishing this modification, I'd be grateful if you'd let me know how you did it. I've been trying for years! I even have a copy signed off by a particular FAA inspector, on different airplane, who will not sign off on another one.

As a matter if interest, when it comes to a physical fit, Cessna wings are interchangeable on the C-170, early C-172, C-175, C-180, and C-182.

I'm acquainted with a fellow who has a tailwheeled early C-172 who has installed a set of C-182 long range wings. He removed the electric flap mechanism and installed the manual system. Bootlegged, of course. He did it for the tankage when flying in the back country where fuel is scarce.

blueldr wrote:...As a matter if interest, when it comes to a physical fit, Cessna wings are interchangeable on the C-170, early C-172, C-175, C-180, and C-182...

If I recall correctly, L-19 wings offer increased fuel capacity and will also fit B-models. Again, the rub is the approval.

Miles

Miles,
I think you'll find that L-19 tanks are the same capacity as the C-170, but the flaps are quite different. Instead of being track mounted as all the rest of the Cessnas, they are hinge mounted, as on a Super Cub, and will deflect down to a much greater degree.

The C-175 wings carry an additional six gallons on each side, and they're the same as the C-172 "Long Range" tanks. They have electric fuel gages
rather than the mechanical gages we have in the C170B.

The end of Oct. I received my Field approved 337 for installing 175 wings on our 171. I sent in the copy of the letter from Cliff Ives, the former Cessna Tech rep outlining the 5 areas of required compatability ( kinda sounds like E-harmony ) as well as copies of the parts manual lising the early 172 as well as the early 175 wings as using the same parts except in the fuel bay area. I also listed the part numbers of the fuel gauges and sending units OR current equivelents needed for the fuel quantity conversion to be installed. In addition I sent copies of the TCD sheets listing the gross weight of the 172(2200) and the gross weight of the 175(2350) that the wings came off.
I had talked to my PMI about this before hand and had to race to get it in before he retired at the end of OCT. Now it will be interesting to see what response we get in the future from his replacement.

Indopilot, I would suggest you send copies of all your paper work on your conversion to Jan at Headquarters. Who knows, your efforts may help another association member, replace his wings as our planes age.

Also, congratulations on getting your field approval.

Don't forget that although the 175 has 52 gals capacity, it also has 10 gals unuseable. (Probably due to the "all attitudes" restrictions on "useable fuel.")

gahorn wrote:Don't forget that although the 175 has 52 gals capacity, it also has 10 gals unuseable. (Probably due to the "all attitudes" restrictions on "useable fuel.")

Hmm, brings up the question, does the wing determine the unusable fuel or the aircraft they are installed on? What has been the determination of the FAA for those who have managed to get this conversion approved?

If you are running a stock 0-300 / C145 and planning on keeping it so you really don't want to haul extra gas... If you always intend to fly from Phoenix AZ to Kansas City MO, - - non-stop and land and take off on 6000' runways you might be happy with the extra tank capacity. If you go into short fields at hi D/A and loaded you are much better off to let the stock tanks ride along cause of the extra weight and arm. I have a 1961 C175 and can relate for cerain that even in that airframe flying the full tanks to empty does change the flight characteristics . Also the electric fuel gages are not very reliable and can cause sudden sounds of "silence" if relied on for accurate measurement.

I doubt the "addition" of 10 gal unuseable. All the extra capaci ty is at the outer and front end of the tank thus uphill both ways from tne original tank profile . Fuel can't stand there unless you fly on a cross controlled 10* bank!

The "unuseable" fuel amount on the C-175 is Cessnas CYA due to the fuel porting arrangement, same as on the C-170B.