bc12d Trim System bolts

[Laz]

I am trying to find out what are the correct bolts that go in the trim system bell crank inside the elevator. It appears that normal AN bolts will rub the fabric. The main bolt seems to have a very narrow head on it but the other two I am not sure of. Any Ideas ore drawings that can help?

[Ragwing nut]

Re: bc12d Trim System bolts

AN bolt with the head ground down

[flybikefarm]

Re: bc12d Trim System bolts

That's what you get when a KID works on an airplain!!!!! George

[jpowell]

Re: bc12d Trim System bolts

Try an "AN-23" Clevis bolt.

[Ragwing nut]

Re: bc12d Trim System bolts

That's what you get when a KID works on an airplain!!!!! George

Excuse me? I hope that comment was a joke. The ORIGINAL is an AN bolt with the head turned down.

[Ragwing nut]

Re: bc12d Trim System bolts

Try an "AN-23" Clevis bolt.

AN-23 will work just fine, but not "correct" as he asked. That is what I use when the original bolt is missing or bad.

[Laz]

Re: bc12d Trim System bolts

Since I was the “kid “ who covered this airplane in 1970 I doubt that I replaced the original bolts. There was no lathe in my parents 2 car garage so turning down the bolts was not possible. I don’t think I even had a grinding wheel. I was just curious what the factory used. My parts list from 1970 does not list these fasteners.

Mine need to be replaced because of some wear. I am trying to get the trim system as slop free as possible. I plan to post some pictures of my project soon, as long as the “tribe” doesn’t make too much fun of an old man restoring his first airplane. Any suggestions on the best way to do this? I am thinking the Picture gallery may be the best but there may be a better way.

[Robert Lees]

Re: bc12d Trim System bolts

Don't worry too much about the "ribbing", Michael...we're generally a friendly bunch. (Evidently George knows more about you than he's willing to let on so far).

If anyone takes it too far, let me know by reporting the post or sending me a Private Message.


When I recovered my elevators, there was indeed what appeared to be a standard AN3 bolt with the head trimmed down. Of course, there's very little load (and all in shear) so a smaller bolt head will not be detrimental to safety. I guess back in the '40s they just did what was necessary, and I doubt drawings would show that level of detail. In fact mine was so unworn, I reused it.
If I recall correctly, I "remade" the main trim bellcrank using a solid button instead of the weigh-saving made-up piece (see here for photos)

I did address wear in some of the other aft trim mechanism holes, however, by "punching" & re-reaming the bellcrank.

I also glued a 1" diameter aluminium patch on the underside of the fabric, where this bolt head sits, so as to reduce wear & tear on the fabric & paint.

I reckon a Clevis bolt, as jpowell & Ragwing suggest, would be another way, also perfectly legal since it satisfies the requirement of being "of equivalent" in FAA-speak.

We'd love to see pictures of your project. You can either post them in the Gallery (there's loads of webspace there) or you can use a third party image host, such as Photobucket, or even have your own webspace (as I do).

Hope that helps.

Regards,
Rob

[flybikefarm]

Re: bc12d Trim System bolts

What goes on in Margaritaville stays there, Mike is a great guy know him well!!! George

[Laz]

Re: bc12d Trim System bolts

Than for the kind words George. Problem is now I have to live up to them. As far as the bolts go I did replace the belcrank with one I found in perfect shape. I can use the original bolts but the plating is gone.

The fact is I don't know what I would do without this forum, Forest Barber, George, Bob Lees exelent pictures and others. When I recovered it in 1970 life was simple. Take off old covering remove rust, have AI inspect it re-cover in Ceconoite and Dope, AI inspects and GO FLY.

Now 39 years later everything I touch is a project. If I can't find it it has to be made. Wing tip bows, Fuel Tank Straps, Trim cable guide, wood door frame, boot cowl, nose cowl and the list goes on. Add to that the fact that no two Tcrafts are ever the same, makes this project a lot bigger, time consuming and expensive than I ever imagined. Of course everyone on the forum already knows that.

Pictures will start on Sunday. I expect to be picked on, thats's the real fun of doing this.

[Robert Lees]

Re: bc12d Trim System bolts

Now 39 years later

That is a phrase to ponder.

It's been along time since a lot of Taylorcraft were certified. Approaching twice that time for most. In those "good old days" of cotton and Irish linen, the airframes needed recovering every 5 years or so, and there were lots of places keyed up to do it (almost as part of the annual), so it was cheap to recover.

In the intervening years, polyester fabrics came along, with the STC's, and a much greater longevity of the fabric. The fabric skills were weaned away by natural decession, so those that knew how to do it cheaply disappeared. Natural progression, if you like.

Now these old airframes that we own, that were intended to be opened up every 5 years or so, are not opened up so often...possibly just when they need opening up. The Dave Wiley accident may have been a reminder to us all.

If we're honest with ourselves, a lot of them need stripping down to their bare essentials to understand what age and time has done to them.

We're very lucky that they are relatively simple airframes, where age-related deterioration and damage is easily recognised during annuals and other regular inspections, if the owner/pilot is aware of the real issues relating to such old aeroplanes. I've recently done some annuals on stressed-skinned Cessna's that have a very rigorous "age-related" inspection regime, and we're lucky by comparison.

The FAA has recognised this with the "ageing airframe" proposal...but we owners of old aeroplanes have a major part to play in ensuring that these 60-year-old aircraft are safe in the skies.

If we can't do this, then we'll all end up flying some modern LSA that looks and sounds like a lawnmower. I won't be happy doing this until I have exhausted every other option.

Sorry if I've gone off on one...

Rob

p.s. Michael...we'd still like to see your project photos! Tell us where they will be.

[Ray36048]

Re: bc12d Trim System bolts

I THINK ALL OF THE APPLIES TO THE PILOTS ALSO.(;f

[DanBrown]

Re: bc12d Trim System bolts

Ah well, such is life..
But I was too young (just 8) when my ship was first flown, so I've had to grow into her. Now I've found a good AI who knows old tube an fabric aircraft, so my Tcraft annual went very nicely.

But I needed the combined efforts of a dentist, dermatologist, cardiologist, oncologist, radiologist and their staffs to certify me for another year (and make the minor repairs required). I'm keeping a lot of people employed!

So my head is as solid as ever. Now where did I leave that check list? That's OK, I remember it all...

[Carl E. Carson]

Re: bc12d Trim System bolts

Dan: If all you fly is the T-craft you might consider going Sport Pilot and not have the medical worries as long as you have a valid driver's license.

BTW, my '40 BC-65 is NC29624

Carl

[DanBrown]

Re: bc12d Trim System bolts

I am flying as a sport pilot these days. My medical checkups are for myself and my family -- hopefully both I and my TCraft can keep flying for at least another 10 years.

N26625 came off the line in July 1940, serial number 1967

Dan