trim indicator

[birdlegs]

Re: trim indicator

I've got a '46 BC-12D and theres a drawing of it in the manual,but it doesn't exist. The crusty old I.A. that signed it off in those days the late John Seablom (Sean Coleman will remember him) just barked at me when I asked if it could be installed.John said:and I quote[just look at the tab on your walk around and adjust it to neutral before you start it!]end quote.So mine don't have a sign of one, is this required to license one?
Wally Olson had two BC12D's in part 135 and they didn't have them either,sometimes the trim handle even worked! Aren't we supposed to "feel" these airplanes?
Is this a category for purist's ? if so I need to shut up

[birdlegs]

Re: trim indicator

Mr. Powell
Thats a fine rendition, and good use of of the design.I'm in a position to bring mine into function and think this is a fine example.,hear hear!

[Joel Severinghaus]

Re: trim indicator

I discovered, when I peeled back my headliner fabric last weekend to install missing trim indicator pieces, that my indicator shaft had been cut off right above the pulley nut at some time in the past (left photo). The original indicator pointer bracket assembly was still there on the wood former, but the loose tip of the wire has apparently been rubbing against the pulley. Yikes!

The good news is that the Texas factory still has most of these pieces in stock: the pointer bracket assembly (p/n B12-A128), the lever assembly (B12-A137), the plate (B12-A130), and the shaft (B12-197). There's a good diagram of the mechanism in a 1970s Ohio factory Parts & Price List (below -- sorry I scanned it sideways.)

The indicator shaft, with the pulley in place on it, has to drop down into the control crank bracket from above, so there's no way you can install this if there's fabric on the airframe. There's only a few millimeters of clearance between the top of the shaft and the fabric.

As it was, my shortened indicator shaft allowed me to lift out the pulley (with some nerve-racking bulging of the fabric above) so I could remove the old bracket assembly and install the new one I'd just bought from the factory. Couldn't install the lever that moves the pointer wire, so just safety-wired the pointer wire in neutral (middle photo.)

The factory is out of the placard (B12-928), but I'm deeply indebted to Rob Lees for sending me one of his home-made stickers (right photo.) So the indicator plate looks great, but it's just for show, and I'll still be counting trim crank revolutions. I'll put the lever and shaft carefully away in a box somewhere, and hope I or my heirs can find them thirty years from now when it's time to replace the fabric...

[flyguy]

Re: trim indicator

Joel, if your plane had as many patches on it as mine you would know exactly how to take care of the problem. Chuckle.
Darryl

[Joel Severinghaus]

Re: trim indicator

Darryl,

I did think about cutting the fabric above the pulley and putting in a round inspection hole cover or a screwed-in inspection panel, but my mechanic quickly talked me out of it, pointing out that would be an excellent place for water to get in the fuselage.

[VictorBravo]

Re: trim indicator

my mechanic quickly talked me out of it, pointing out that would be an excellent place for water to get in the fuselage.

I have to strongly disagree. Although it might be wrong from an originality standpoint (on a champion antique like this one), it can EASILY be prevented from becoming a water leak.

Go to any medical supply company or hospital supply, and get a roll of 3M "Blenderm" surgical tape. This is the same stuff as the stretchy "transpore" first aid tape that you can by over the counter, but it does not have the holes in it. If you have any model airplane clubs nearby, one of them might have a roll of this stuff, they use it as hinge material.

Make any sort of access panel, inspection cover, Wilkie button, etc. that you want. When you are done removing the pulley and playing with it, put the cover back on and tape over the gap with Blenderm tape. It will be 100% waterproof. The Blenderm is also transparent so it will not show.

The Blenderm is a little tedious to remove because it sticks so well, and you might want to experiment with a coat of wax to make it a little easier to remove. After you get it off, use "Goof Off" or Xylene to clean the tape residue without screwing up your paint.

[Robert Lees]

Re: trim indicator

just for show

I challenge any EAA judge to tell the difference. Black on silver foil, as per the original.

Joel, my trim indicator needle works just fine. With the $/£ rate as it is, you need to come and look at ours. You could treat your lovely and ever-patient Beverly to a trip across the pond. London is lovely in spring.

I also agree with Bill...in that if you don't have a skylight (removable for access to the forward trim mechanism), then show me a fuselage fabric drawing that doesn't show an access panel above the trim mechanism. Our 1941 Tcraft has one...and I don't care if it's original or not, it makes sure I can maintain the trim system safely, and it don't get no moisture in it (but it is hangared).

Good maintenance comes above so-called "originality", surely, especially since the judges won't be able to know the difference?

Incidentally, the best way to prevent moisture ingress and / or damage to an aircraft is to fly it regularly and often.

[jmvolpp]

Re: trim indicator

Here's another plug for the skylight (and practicality), as it also provided a solution to the trim indicator issue. Mine did all the annoying things described above, so it wasn't a huge disappointment to remove it when the opportunity presented itself. With the trim tab in neutral, the cable was painted white between the pulley and first fairlead - I've since added orange stripes to make it more visible.

Mike V.

[Joel Severinghaus]

Re: trim indicator

Bill, Bill, Bill -- for some of us, aesthetics are as important as practicality. Otherwise, we'd all be flying Cessna 150s rather than Taylorcrafts, right? But I do concede you have me convinced that it would be possible to waterproof an access panel with your methods.

If I were going to cut the fabric (OK, maybe after Oshkosh judging this year), I'd be inclined to install a 4 1/2 x 7 1/2 inch rectangular panel rather than a round cover, to match the two inspection panels on the top of the wings over the aileron bellcranks. Has anyone seen that done?

Rob, thanks for the kind offer, but I see on the news that London has more snow on the ground than Des Moines does now! (Besides, Bev wants an April trip to Kyoto and hot springs resorts in Japan.)

Mike, your solution is brilliant. I wonder if there are more absent or non-functional trim indicators out there in the Taylorcraft fleet than original functioning ones. I also like the crank bezel pictured below, which I saw in a Taylorcraft at Oshkosh last summer. I've just been using a mental reminder of "clockwise, up" whenever I turn my trim crank.

[VictorBravo]

Re: trim indicator

Bill, Bill, Bill -- for some of us, aesthetics are as important as practicality.

Granted, and in the case of your ship aesthetics have been taken to new heights.

So make up an inspection panel that perfectly matches the fabric and almost disappears.

I'd make it out of birch airplane plywood, and cover it with fabric and paint to match your airplane. There's no reason your access panel can't be covered with fabric regardless of what it's made of. If you want to be super-clever about it, you can even cover it with stretched fabric to match the curve or tautness of the surrounding area.

If you were based anywhere around here I'd offer to make one up for you, but any old broken down model airplane builder can do it.

[Doc]

Re: trim indicator

Buell: Got your msg re the prop...could use a trim handle...Mark just rebuilt the indicator. Doc

[Joel Severinghaus]

Re: trim indicator

Bill, if I did install an inspection plate (and you and Rob have me wavering), I still think I'd do a p/n A-7009 rectangular plate with a reinforcement ring under the fabric and ten little screws, like for the aileron bellcranks. The drawing says that plate could be scrap aluminum, pyralin, or plywood. Painted aluminum would be acceptable for my fussy aesthetic standards, I guess, rather than trying to disguise it with fabric.

The L-2 drawings include one for "fuselage inspection frames installation", drawing D-(A)175, which shows where all the various-shaped inspection plates go. Has anyone seen a similar drawing for the BC12-D?

[VictorBravo]

Re: trim indicator

OK, whatever you decide. Just know you have a choice of whether to make a stealth hatch that nearly disappears, or one that looks like what a Taylorcraft factory hatch would have looked like. The clear tape will work on either one and keep you dry as a bone.

Remember they built the airplane to have the cotton stripped every few years, not to go 20-40 years on the same polyester. There are many many areas on the airplane that they had every right to think would be exposed far more frequently than what actually happened.

[3Dreaming]

Re: trim indicator

I think I would make a triangular cover plate with the front edge tucked under the top windshield trim piece. Also the size of your hole does not need to be that large. If you had a scrap of already painted to match fabric removed from an inspection opening it could be glued over the small hole. Tom