V brace (dash) for 1956 172

[Lhorn]

Hello all,

Can anyone direct me to where I can get approval for adding a v brace (like the float planes have) to my 170C?
Is there an STC, or is it just a 337?

Any help would be appreciated!

subject title edited by moderator..note to all….he has a 172

[n2582d]

Which plane do you have, a 1956 C-172 or a 1962 C-172C?

Cessna made V-brace p/n 053003-15 for the 1960 C-172A. For the 1961-1962 model years they used p/n 0513003-5. FA Dodge has an STC for a V-brace on the C-170B. You might try talking to them to see if that would fit on an early 172. It would require a field approval/337 form if it does happen to fit as the 172 is not on their AML.

[Bruce Fenstermacher]

He has a 1956 172 which is exactly the same fuselage as the '56 170 both being built at the same time on the same assembly line. The c in the subject line probably stands for Cessna but is confusing. Why FA Dodge doesn't have the 172 on their AML is a mystery to me. Lhorn is in Alaska I believe so a field approval should not be an issue. Maybe AF Dodge can use his install to add the 172 to they're STC AML?

[Lhorn]

Hey guys, called the local FSDO, and waiting to hear back. Plane is in Ohio being worked on, but will live in Alaska when I get her flying again, hopefully by the end of May. Hoping the FSDO sees the logic in what I'm trying to do with the V brace. What I really need is a 337 from someone who has done this before. That would really speed things up for me, and F. Atlee Dodge says they don't have anything for me to go on. Hoping someone in the community can help out. I know I've seen youtube 172c's with the V brace installed. Maybe I can try to track down their records if I can lift their tail number off the video...

[Lhorn]

From my understanding, the square tail Cessna 170 was type certificated as the 170c in 1955, but none were ever produced. The square tail 170 became the platform for their first evolution tricycle gear and re certified as the 172 to try and compete with Piper who were stealing their market share with their new tricycle gear. So technically, it's a 170c. My typo calling a 172c...

[Lhorn]

Now seeing the title of this thread, I realize how confusing it is. Wish I could change it. Meant to say 170c

I started posting questions on another thread with a better title, but basically what I am trying to do at this point is find someone who has done a 337 for putting a V brace in a 172. If not, we've already started the ball rolling with local FSDO, and hopefully I will have one to share, but being the first to beat a path is, well, expensive.

BTW, the V brace from Atlee Dodge has an STC sticker right on it, so getting it installed with a field approval seems dodgy.

DONE per moderator

[Bruce Fenstermacher]

Lee, you should know that thought the '56 170 and 172 were produced on the same line at the same time with mostly the same parts, they were certified under two completely different type certificates. The 170 TCDS is A-799 and the 172 is 3A12. Lots of Feds today will look at that alone and say the two aircraft are completely different aircraft with nothing in common. Perhaps you will find a smarter Fed.

The fact that the V brace may have a sticker touting an STC has no bearing on getting a field approval for its installation on an aircraft that is not listed in the STC AML.

Also forum moderators can fix (or screw up) nearly everything on the forum. Removing a c in a title is a minor job so long as there isn't 5 pages of posts. Just ask and we can probably fix it. Do you want 172C, or 172c or 172 in the title?

[Lhorn]

I think you are right, it should be 172 in the title, because tgat is what it is.
Mechanic sees no problems getting it field approved, just be nice to show some prior approval if anyone has that documentation. There's got to be someone who has done it...

[Bruce Fenstermacher]

If you come up with an N number, email it to me and I'd be happy to assist you in looking at those records.

And just like magic, all the titles are now 172.

[Lhorn]

Really appreciate the help Bruce. I'll spend some time searching on youtube and see if I can come up with an N number.

[n2582d]

N7001A is a ‘56 172 with a V brace. It has a 337 form indicating that the C-170 seaplane kit was installed but that kit doesn’t include a V brace. There is no other paperwork to indicate when it was installed. Could be the mechanic considered it a minor alteration.

IMG_1737.jpeg

[GAHorn]

(The following comment is offered only as a discussion-point as regards “minor alterations”. I’m not criticizing this particular airplane or this V-brace.)

It’s a foggy-area to make a “minor” claim to an alteration on a certified airplane. A V-brace might be added if the owner manufactured the actual brace, perhaps. I’m thinking of the minor-alteration-status of a hemp-rope looped thru the rear seat-belts used for a pilot’s shoulder-harness…..(completely legal on a 170….but not on a 1990 C-172).. as opposed to using a B.A.S. hardware kit drilled-through the rear-wing-spar hat-section …without the STC approval that restricts how that is accomplished.

As for THIS airplane, it was likely “approved for return to service” by the subsequent AI, if it was logged into the records.

The purpose of a V-brace is to strengthen the forward fuselage and engine-mount against the pounding a seaplane receives. There’s not much “spring-iness” or “forgiveness” when a flat-spring landing-gear is replaced by tube-strutted-floats.

[cessnut]

Purpose of a V brace is to keep the windshield in place and save fatigue on the connection between the door posts and carry-through spar. Doesn't do anything for the motor mount.
Wipaire has the STC.

[GAHorn]

Without the V-brace the weight of the engine on the mount in pounding waves is what stresses the windshield/fwd-spar/fuselage.

[Lhorn]

Check out this bolt that came out crooked! Definitely some stresses there!

Good find on N7001A. Thanks for that. I'll pass it along to my IA and see what he says. He's been around long enough to know when he can push things and when he can't. That STC sticker on the Atlee Dodge brace threw up a big red flag, though when I called Atlee Dodge, they suggested he just sign it off with a logbook entry since there is no effect on weight & balance, or change to flight characteristics.