AN5 torque value

[SpecialT]

Is this a good document for torque values on the Taylorcraft? I'm specifically looking for the torque values for the AN5 and AN4 wing and strut bolts. I perused the 12 service manual but didn't see any values.

Thanks, David

[Robert Lees]

Re: AN5 torque value

If you are referring to the bolts that are in shear (for example the bolts attaching the wings to the fuselage, the struts to the wings, and the struts to the fuselage) then the shear torque values apply. Remember, when a bolt is in shear, the only purpose of the nut is to stop the bolt falling out!

There is a special case with the Taylorcraft...that being the bolt at the bottom of the lift strut, where the footstep attaches. It is quite important that the bolt tightness be low enough so the footstep can be swivelled by hand pressure; otherwise the welded fitting on the lower fuselage longeron would be " crimped up" a lot and could induce stress cracking. (Also, the nut on this bolt should be castellated with a split pin)

Rob

[SpecialT]

Re: AN5 torque value

Thanks Robert,

My steps were tight, but I think my bottom fitting has been modified with an extra gusset and changed angle. I'll check it out when I get them on. I ordered a couple longer bolts as two of mine were a little short allowing the tab to rest on the threads.

It's really a hassle getting the front AN5 bolt seated that attaches the wing to the fuselage, inbetween the windscreen and wing root. Any secret to lining it up and getting it in? The wing straps also are tight on one side requiring they be spread 1/8" to get it over the fuselage tabs making it more of a hassle. I'm going to use a sheet rock lift to support the wing and help line it up. I dont' really like scraping all the zinc chromate and paint off the tabs trying to get it bolted.

Remember, when a bolt is in shear, the only purpose of the nut is to stop the bolt falling out!

That's good, it will make me feel better when I mangle the threads getting that front one in.

[Robert Lees]

Re: AN5 torque value

No great secret...they made 30 aircraft a day in 1946 (so 120 wing attach bolts per day!) But I would strongly recommend using close-tolerance bolts (An175 and An174 for front & rear respectively) for the wing attach fittings. These 50-60-70-year old airframes could do with all the help they can get.

I use a "bullet" to lead the bolt in.

What do you mean by "wing straps"? Got a photo?

Rob

[SpecialT]

Re: AN5 torque value

What do you mean by "wing straps"? Got a photo?

Uh, upon inspecting inside the wings with a borescope it looks like each "strap" (wing attachment fitting) is on each side of the front spar bolted through the spar and to each other with at least 5 or 6 bolts. So i referred to them as straps. My wings are not open and the slot for the pitot is small so my observation is limited. I'm not sure what my kids did with the camera at the moment.

[astjp2]

Re: AN5 torque value

I can see someone scrapping another set of spars if they use the torquing method...

[astjp2]

Re: AN5 torque value

I used an bolts with cotter pins, barely finger tight because there is nothing to prevent crushing of the attach fittings. They are only in shear and as long as they dont fall out, you are OK! One former member on here (DOT) tried to torque the bolts for the spar compression tubes, it wound up crushing the wood under the washers....Tim

[SpecialT]

Re: AN5 torque value

Ok, the kids have the camera so I get to use the $10 Malaysian borescope. Here are some pictures for entertainment value. Thanks for the heads up on torque. My fuselage wing mounts have a length of 5/16 I.D. tubing between the tabs. The wing spar fittings go on the outside of the fuselage wing mounts. To compress the spar would be pretty hard as you would need to bend the fuselage tabs and crush the metal tubing.

Hey, as an aside, can you see the rib tape on the ribs and the rivets?

[flylo]

Re: AN5 torque value

Don't forget the LPS 3 where the lower lift struts connect to the fuselage & steps.

[SpecialT]

Re: AN5 torque value

Well the 5 year old was playing with the rudder, or when the wind came up, I got a 4" tear in the rudder in the same area that had been previously has some kind of silver/gray repair done, so I asked the little boy if he did it, to which he shook hid head "NO." So I bought one of these

http://www.aircraftspruce.com/catalog/cspages/pfpracticekit.php

And I'm going to give it a go and "practice" some fabric repair. I'm not sure what's up with the fabric until I sand off the paint, but the fabric looks green around the rudder tear. The fuselage fabric is white on the inside, and clearly says "Polyfiber." And the wings are pink on the inside and say "Polyfiber." The log books only say "Recovered with Poly stits."

p.s. Bought some Corrosion-X for the lower lift strut brackets

[Guest]

Re: AN5 torque value

Well the 5 year old was playing with the rudder, or when the wind came up, I got a 4" tear in the rudder in the same area that had been previously has some kind of silver/gray repair done, so I asked the little boy if he did it, to which he shook hid head "NO." So I bought one of these

http://www.aircraftspruce.com/catalog/cspages/pfpracticekit.php

And I'm going to give it a go and "practice" some fabric repair. I'm not sure what's up with the fabric until I sand off the paint, but the fabric looks green around the rudder tear. The fuselage fabric is white on the inside, and clearly says "Polyfiber." And the wings are pink on the inside and say "Polyfiber." The log books only say "Recovered with Poly stits."

p.s. Bought some Corrosion-X for the lower lift strut brackets

Hello,

Red text above makes me reflect on these few things;

1) 5 year olds cannot tear good fabric, probably even if they have a sharp knife,

2) Wind that is strong enough to tear good fabric will probably blow a 5 year old away,

3) The tear is in a place that had previously been repaired,

4) Maybe the fabric is not good?


So all that makes wonder if the fabric is any good, what was it's last test value and when was it done would be things that I would want to know if it was mine.

You may need a rudder recover rather than a repair. Of course I don't know if that is the case or anything about the history of your plane but knowing the test result and time frame would be valuable for you. Perhaps you already know that info.

Hope this helps, Dave R.

[flylo]

Re: AN5 torque value

When I built my hanger here on the farm I had planned on a Bifold door & bolted 5 trusses together & used a 30x40 tarp folded so it was 40x15. That door faces west & my my youngest son would crawl in the tarp & the wind would blow him up to the trusses. I ended up welding 2 pair of 15' wide 13' tall bifold doors like giant closet doors & they've worked great since 2000. I sold National hardware track with 1 barn door roller per pair & mounted the on a 3"x5" 3/8" angle bolted to the post in a way I could adjust for sag & they've never sagged. You can still pick up the center end on pair & rattle the roller. The next year at OshKosh there was a bolt together kit exactly like mine using National track & hardware. You can open them with 1 finger & when & built them I had no idea if they'd work.

[SpecialT]

Re: AN5 torque value

Yes, the damage was prior from wind slamming the rudder into the elevator as the rudder stop bolts were not adjusted out far enough, I just replaced the bolts and installed longer ones and adjusted the rudder. There was a painted gray patch on the rudder, I didn't think the youngest son did it, but obviously the fabric is weak in that area. I'm not sure when I am going to get to sanding it out to take a better look. My mechanic said he wanted to fabric test the plane, but he's out of state and I'm doing all I can before I get him over here. No log entries on lbs. test. The previous owner was an IA.

If I was in Alaska I would put a piece of duct tape on it and fly it home. It's on the left side and who uses left rudder?

[Guest]

Re: AN5 torque value

I had fabric damage like that too even with good fabric, best wishes, Dave R.

[SpecialT]

Re: AN5 torque value

Sounds nice. I was wondering how many trusses you would need to use on the gable end, and how heavy of a door you could hang on it. 5 sounds beefy enough. Unless you have "Ag" property out here in California I don't think you can get away with an Ag building like that. You must pull a county permit and only way to avoid engineering is to build "code conforming," and only a 16' garage header would fly. So you are stuck with and engineering fee, and then the county doesn't want any liability, so they want your engineer to write a letter saying they inspected it and it's OK after you frame it. We build a 40' x 50' metal building with regular shop door roll ups and the county required the engineer inspect the concrete footing also. I think Big Al's cousins run the place.