Horizontal stab attach bolt hole

[TimHicks]

Any comments on the thru hole(s) where it attaches to fuse?

[Larry Lyons]

Re: Horizontal stab attach bolt hole

Looks like it went from one plane to another. With the wires in tension that stab will not be going any place, in my opinion anyway. However because it is not a moving part and not a structural part, a weldment should be an approved fix but we will see as there are way more qualified people that will weigh in here.
Larry

[TimHicks]

Re: Horizontal stab attach bolt hole

You may be right about it being moved from another airplane becasue both the leading edge hole and the trailing edge hole look like this, twice drilled. But only on one of the two stabilizers. The other one shows no evidence of being double-drilled.
My IA is a good welder and he says the thing to do is weld it up and redrill it correctly. Just wanted to bounce it off of the tribe.

[DPKII]

Re: Horizontal stab attach bolt hole

Tim,
I have seen horizontals with round plates (fender type washers) bent to match the tubing and welded over the bolt holes. I don't know if this was factory or not but the tubes only showed evidence of one hole on the inside. In other words, the washers were not welded on to cover a miss-drilled hole. My thinking was that they were there to keep the tubing from crushing in case of over-tightning of the mounting bolts. In your case a washer or small plate welded over the area may be a good way to fix the double holes.

David

[Robert Lees]

Re: Horizontal stab attach bolt hole

Weld it up and redrill.

Photo:


Full text & photos about 1/2 way doen here.

[Guest]

Re: Horizontal stab attach bolt hole

You may be right about it being moved from another airplane becasue both the leading edge hole and the trailing edge hole look like this, twice drilled. But only on one of the two stabilizers. The other one shows no evidence of being double-drilled.
My IA is a good welder and he says the thing to do is weld it up and redrill it correctly. Just wanted to bounce it off of the tribe.

Hi Tim,
AC43.13-1B chapter 4 page 42 says this;

4-60. STEEL AND ALUMINUM FITTINGS.
a. Steel Fittings. Inspect for the following
defects.
(1) Fittings are to be free from
scratches, vise and nibbler marks, and sharp
bends or edges. A careful examination of the
fitting with a medium power (at least
10 power) magnifying glass is acceptable as an
inspection.
(2) When repairing aircraft after an accident
or in the course of a major overhaul, inspect
all highly-stressed main fittings, as set
forth in the manufacturer’s instruction manual.
fittings.
(4) Elongated or worn bolt holes in fittings,
which were designed without bushings,
are not to be reamed oversize. Replace such
fittings, unless the method of repair is approved
by the FAA. Do not fill holes with
welding rod. Acceptable methods of repairing
elongated or worn bolt holes in landing gear,
stabilizer, interplane, or cabane-strut ends are
shown in figure 4-25.

The figure basically shows how to make a repair washer and weld it on.

Dave

[Hank Jarrett]

Re: Horizontal stab attach bolt hole

Looks to me like you need a stepped binocular bolt. The shank has an overlapping double diameter in the stab holes and a single diameter in the airframe hole. Provides great load capacity and no play but are a pure B**CH to put in. ;-) When I worked for the Navy we had a set of "special fasteners" that were a riot to show to mechanics for use in "special" repairs.
We also had "Joggle bolts" (for misaligned bolt holes), offset head bolts (to hide holes too close to the edge) and angle bolts (shank angled from the head so a crooked drill line is hidden). They were all gags, but hilarious the first time you gave one to a mechanic.
Hank

By teh way, I have seen the washer repairs and they seem to work well.

[flyguy]

Re: Horizontal stab attach bolt hole

Thank you very much Dave. I have one with the forward hole just a tiny bit loose. I'll have to read your reference in in 43 if it turns out to need repair.
Darryl

[TimHicks]

Re: Horizontal stab attach bolt hole

Thanks for everyone's advice. What's interesting is that both stabs, on both the leading and trailing edges, have fore/aft (horizontal) holes that are reinforced with a washer. When would these ever be used?
The tube in the fuselage only has holes for the vertical bolts that were installed.

[Guest]

Re: Horizontal stab attach bolt hole

Thanks for everyone's advice. What's interesting is that both stabs, on both the leading and trailing edges, have fore/aft (horizontal) holes that are reinforced with a washer. When would these ever be used?
The tube in the fuselage only has holes for the vertical bolts that were installed.

My guess is when these part were used on a pre-war fuselage. Pre-wars had horz. bolts.

Or it could be that somebody just decided to go to vert. bolts instead.

Is your a/c a pre-war?

Dave

[TimHicks]

Re: Horizontal stab attach bolt hole

No, it's not a pre-war. N96872 is a 1946 BC-12 with a Continental 65. I didn't know that pre-war birds had horizontal bolts. So I guess that the horizontal stabs are interchageable between pre and post war aircraft.
I'll re-check the logs to see if they indicate anything about replacing the tail somewhere in its history.

[Acroeric]

Re: Horizontal stab attach bolt hole

They will fit but most pre-wars have 3 hinges, post-wars have 2 hinges per side.

[TimHicks]

Re: Horizontal stab attach bolt hole

Aha. My stabs and elevators have 3 hinges per side. So this means that they are prewar, right? But I have a metal trimtab with the jackscrew-type actuation. I share a hangar with a yellow 1941 (pre-war) TCraft and its trimtab looks very different. And its rudder has 3 hinges while mine has only 2.

[Hank Jarrett]

Re: Horizontal stab attach bolt hole

My 41 is 3 hinge but has vertical bolts and a jack screw trim. I am to the point that I don't expect ANYTHING to be "standard" on a Taylorcraft.
Hank

[Laz]

Re: Horizontal stab attach bolt hole

does anyone know the proper bolt that is used to attach the rear post of the vertical stab to to the rear post. is is a an hex bolt or one with the slotted head? It seems that a hex head bolt is too thick and will interfere with the rudder