1939 trim tab

[clayton]

I need a trim tab for my 1939 BC-65, does any one have a trim tab for sale or how about a picture or drawing of the fuselage mounted trim tab?

I was told the original trim tab was mounted under the horizon stabilizer to the tail, can anybody confirm this? At this time I am unable to find any pictures, drawings, or technical data as to the location and/or shape of this trim tab. Any help would be greatly appreciated.

[Guest]

Re: 1939 trim tab

Hi, yes they were under the stabilizer. Look for a couple of short pieces of tubing with about 3/8" or 1/2" id situated so as to slide a piece of tubing thru them to act as an axle that is parallel to the horz. stabilzer spar.

And then go to ebay an search for this item # 190089547496.

You lucked out, it was not sold (and it is not mine) but it is only half of it, one side.

Dave

[clipit]

Re: 1939 trim tab

i have a pair of those trim tabs and the part they mount to in the fuselage. $90. plus shipping if you want them. greg 716-753-2160

[VictorBravo]

Re: 1939 trim tab

Yeah but just don't get too excited about how well the little external trim tabs will work once they're installed. They are marginal at best. When Taylorcraft went to the closed cowling and 65 HP, the trim tabs were not able to provide full trim authority at high cruise speed, and probably don't slow it down too well on landing either. That's why they eventually went to the "regular" trim tab on the elevator.

[Guest]

Re: 1939 trim tab

I recall using that one, my 39 had a little handle on the left side under the seat to move it.

Now that you mention it I think the installed perfomance and the un-installed performance are about the same.

Mine would be effective for just about as long as it took to get your hand back up on the wheel (round wheel) no matter how much you had tightened the friction.

But you need it installed for the aircraft to meet it's type data.

I have read of this little device being called a a Flettner (may have been in Juptner's books) although it is stationary and does not rotate like a true Flettner device. It does provide transverse force so maybe that's why they called it that name.

Dave.

[1938BF50]

Re: 1939 trim tab

I have not yet flown NC20407 but was told by (2) previous owners that the trim was very effective in the range of deflection. Granted, light plane, light pilots and 75hp. Anxious to see for myself soon, I hope.

[M Jones]

Re: 1939 trim tab

The trim tabs on my '39 work well in the pattern, but are less than marginal at cruise. My left arm gets a lot of exercise on extended X/Cs because I have to constantly hold forward pressure, especially as the header tank lightens up with fuel burn off. That’s with full down trim also. It might be better if I just left it neutral because of the extra drag created, but it makes me feel better to try to use it at cruise speeds I guess…

[flylo]

Re: 1939 trim tab

Mine works fine on the '38 & as I recall also worked OK on the '40. Much be the Michigan air.

[M Jones]

Re: 1939 trim tab

Mine works fine on the '38 & as I recall also worked OK on the '40. Much be the Michigan air.

Maybe that's it Eric. Or maybe it's just the "even" numbered years that have more trim tab authority.

[taylorcraftbc65]

Re: 1939 trim tab

Yeah but just don't get too excited about how well the little external trim tabs will work once they're installed. They are marginal at best. When Taylorcraft went to the closed cowling and 65 HP, the trim tabs were not able to provide full trim authority at high cruise speed, and probably don't slow it down too well on landing either. That's why they eventually went to the "regular" trim tab on the elevator.

True, but they look soooo... cool, and always seem to be a conversation starter at any airport you fly into. Sabrina

[taylorcraftbc65]

Re: 1939 trim tab

I recall using that one, my 39 had a little handle on the left side under the seat to move it.

Now that you mention it I think the installed perfomance and the un-installed performance are about the same.

Mine would be effective for just about as long as it took to get your hand back up on the wheel (round wheel) no matter how much you had tightened the friction.
Dave.

If you oil the leather washers, it will stay at pattern speeds. I had the same problem, and someone here suggested that I do that, and it worked. Sabrina

[Howard Wilson]

Re: 1939 trim tab

Yup, they're not as effective as a cessna trim tab. It'll take a little back pressure off in the pattern like Mike says. I can use it to trim for most of a cross country flight (in stable air), but towards the end it wants to climb, and it has run out of deflection. The size of the shoes you wear and if you can bend your knee may have just as much effect as the trim tab. Laying one or two hands on the dash will also bring the nose down. Maybe that's what the Taylorcraft brick was for!!??? Hopefully it isn't magnetic.

[VictorBravo]

Re: 1939 trim tab

If anyone wants to search the Forum archives, you can see a thread I started about a year ago regarding a solution to this issue. Now most of you know I'd never bend the rules in any way, or even go to the restroom without contacting the local FSDO But talking about the pre-war trim tabs reminds me of what the nice fellow at the fast food restaurants always asks me... "Did you want to Super-Size that??"

My trim tabs work very well

[jdoran]

Re: 1939 trim tab

The trim was only put on the plane to create a maintenance chore beacuse the shaft always freezes up while sitting.

I just lean forward or back in my seat to trim.

[clayton]

Re: 1939 trim tab

Thanks guys for all your inputs.