Wooden trim tab???

[Szpmichael]

Hi all

I've got a '46 bc-12d at Santa Paula airport in Southern California. While my mechanic and I were troubleshooting a stuck trim tab he took a closer look at it and became skeptical of its origins. It is a solid piece of wood with hinges attached by pop rivets. Before sending me back into the air he wants to know if this was a factory part or something that someone just made for it so I'm wondering if anybody has this same setup on their t-carts or knows anything about it. Ill try to attach a photo

Thanks!

[Don]

Re: Wooden trim tab???

I have a BC12D, an early model 1946. It has an aluminum tab. I have never seen a wooden tab on any Talorcraft.

[Hank Jarrett]

Re: Wooden trim tab???

Wooden tabs were used on a lot of Taylorcrafts. My 45 has wood tabs and they are different from the metal ones as they go all the way to the root end and are shaped to the trailing edge curve of the inboard trailing edge.
What sounds a little "off" about yours is they were NOT supposed to be solid. They are from plywood with holes cut in them to lighten them. They have metal fittings and a wire hinge pin that runs the full length of the tab in a slot at the front. The other thing is they should not have pop rivets. The originals had solid rivets (although they look more like they were made from old nails).
I have a drawing of the wood tab here (someplace) and the tab is uncovered and off the 45 right now. If needed I can trace the tab and you can make a new one in a day. The only thing I would worry about is if yours is too heavy. A heavy trailing edge combined with loose hinge or actuating arm could flutter. You DO NOT want flutter in the elevator system. Don't let ANYONE ever tell you a Taylorcraft is too slow to have flutter problems! If it ever happens to you the sound alone will mess your pants!
If you want me to take photos or find (draw a new one) drawings, drop me an email. My box here is ALWAYS full!
Hank

hjarrett2
at
cox
dot
net

Anybody else I owe drawings to, let me know. I am really behind.

If you can't figure out that address you really shouldn't be flying airplanes. ;-)

[Ryan]

Re: Wooden trim tab???

Wood is original to early bc12ds. They have become quite mixed in the field over the years. Taylorcraft switched to metal in may of '46. I will try to find a photo of mine uncovered if someone doesn't beat me to it.

[3Dreaming]

Re: Wooden trim tab???

I think Wag Aero is selling the early wood type, at least for the L2.

[Szpmichael]

Re: Wooden trim tab???

Thanks for the response everybody! Hank I may email you and ask for that drawing in the next couple days. Ryan, can you tell me if your wooden tab has the same setup as mine with a solid piece of wood and pop rivets? If not ill probably start looking to replace it with either the tab on wag aero or from hanks drawing.

[Ryan]

Re: Wooden trim tab???

Well no pic, but no mine is not solid. Looks exactly like the one on wag aeros site, a frame, and is assembled as Hank describes...mine had to be covered with fabric and no pop rivets. I believe the metal ones are interchangeable to if you find one, no need to cover there

[Hank Jarrett]

Re: Wooden trim tab???

There are at least three types of metal ones. The first (and doesn't matter for this discussion) is the flipper on the pre war planes. It doesn't even attach to the elevator. The second is a metal one shaped like the wood ones. The third, and I am guessing most common, is a rectangular one that fits into a cut out in the port (left to you lubbers) elevator.
I have seen pictures of the second type and never knew if they were original or someone made one to replace a wood one. On the wood tabs the hinge line is centered on the false spar that supports the tab. On the metal rectangular tab the hinge is on top of the false spar. IF the hinge is centered (up and down) it was a wood tab.
Hank

[flyguy]

Re: Wooden trim tab???

DO NOT FLY THE PLANE WITH THAT SOLID TRIM TAB on it.

Someone had put one on the first piece-of-junk deathtrap BC12 that I bought. Flying in formation with a old time pilot friend he yelled to me quite loudly. "Get that thing on the ground, the tail is fluttering!!"

I had completely forgotten about that incident and have to add it back to my memory list of deadly things that were wrong with that airplane.

[cvavon]

Re: Wooden trim tab???

FIRST to fix your trim take a wrench and open the inspection plate on the right side of the elevator and turn the nut on the trim jack screw to center the trim tab then NEVER MOVE THE TRIM WHEN THE ELEVATOR IS NOT AT LEVEL FLIGHT OR THE CABLE WILL SLIP AND IT WILL LOCK UP.the photo is a wood trim tab.

[3Dreaming]

Re: Wooden trim tab???

Hank, the notched trim tab was only used for the B*12-65 airplanes like your 41 deluxe. That was the first trim tab they put in the elevator, and it didn't have quite enough authority. I think most post war airplanes had the long trim tab, and most were metal after about the first 5 months of production.

[Robert Lees]

Re: Wooden trim tab???

Hi all

I've got a '46 bc-12d at Santa Paula airport in Southern California. While my mechanic and I were troubleshooting a stuck trim tab he took a closer look at it and became skeptical of its origins. It is a solid piece of wood with hinges attached by pop rivets. Before sending me back into the air he wants to know if this was a factory part or something that someone just made for it so I'm wondering if anybody has this same setup on their t-carts or knows anything about it. Ill try to attach a photo

Thanks!

It is possible that it's not solid. The wood design of trim tab I have seen has large lightening holes in the tab. Of course it's covered with fabric so difficult to see (but easy to feel).

What look like pop rivets I would consider suspect, but it's difficult to comment without seeing it first hand. Is it possible that they have been used in place of original bolts/nuts? Perhaps the drawings will clarify.

Is your elevator two-hinge or three-hinge?

Welcome to the forum! Santa Paula is a lovely field! I flew once from there back in the 90's, and was made to feel very welcome.

[Robert Lees]

Re: Wooden trim tab???

I've taken some photos of the wood trim tab on our 3-hinge elevator.

This particular aircraft was made in 1941, but Pearl Harbor delayed its introduction to the civilian fleet 'til 1945, so it is legally a 1945 BC12D. (it has 3-hinge elevator and rudder and 15 b/u wing ribs for those interested).

Anyway, spzmichael, the pics look an awful lot like yours. But the trim tab is not solid. There are gaps in the structure (lightening holes) that you can feel, but that don't show on these photos through the fabric.

I think and expect that your trim tab is original, legal and safe. You can see that mine is nut-and-bolted (whereas yours appears to be riveted). Perhaps the factory used both methods. Your mechanic/IA is quite right to question these things. I do not believe that your aircraft has a flight safety issue.

Underside view:




Topside view:



Hinge detail:



As an aside, we are all friends here so we often use first names.

All the best,
Rob

[Hank Jarrett]

Re: Wooden trim tab???

Rob, yours looks a lot like mine except my metal bands are shorter on the bottom and are recessed into the wood. My fabric covers the straps instead of the straps being on the outside and there are rivets instead of machine screws and nuts. To my thinking the machine screws and nuts would make no difference at all instead of rivets and would actually be easier to maintain like yours are.
Hank

[Robert Lees]

Re: Wooden trim tab???

I wish that Szpmichael would make a reappearance here.

Perhaps Hank and I could persuade his Mechanic/AI that all is well with the trim tab.

There must be a case, surely, where the absence of detailed approved design data does not mean that the tab is wrong...it just means that the data was not recorded, back in those heady days of the '30s and '40s.