Good day,

I am in the process of mounting the horizontal stabilizer to my LT-40. I have put the wing on and have it fairly well in position. Using a tap measure, I have mesaured the distance from the floor to each wing tip and have found it to be off by a 1/2 inch - 13" and 12.5" for each wing tip. The question is do I need to ensure that the wing is even prior to setting the horiztonal stablizer in place?

Appreciate the help. We'll see if the pic comes through.

Hans

There are many who have a much better knowledge than I do about these things, but I do not think it is a big deal.

The short answer to your question is that the difference will never be noticed in flight. However, if it bothers you, first get the fuselage level. It appears to be a stick of some sort with a flat top across the fuselage so it should be easy enough to get level. Then measure the space from the floor to the wing tips and see how close they are. It could be as simple as one leg of the main gear just a bit longer than the other and projected out to the wing tips, the distance gets greater. Get the fuse level, then check the wing tips.

That is likely caused by your undercarriage being slightly misaligned. Don't worry about it and it has nothing to do with the wing stab alignment.

Here is how I do my wing stab alignment. Mount the wing and measure from the rear of the fuz to each wing tip, adjust till they equalise if required.

Now dry fit the stab and measure from each stab tip to each wing tip adjust till they equalise if required. Mark the stab with a non permanent marker.

Now eyeball it from the rear. By moving your eyeline up and down you can check if the stab tips kiss the line of the wing at the same time. If they don't steal your wife's emery board and adjust the stab slot till they do. Glue and check before the glue sets.

1st, you need to block up the fuselage and not use the landing gear for measuring. This will provide an accurate measurement, where as the LG can flex and be slightly different in height. What IS IMPORTANT is that the main wing and the horizontal stab are parallel with each other. The plane flies on its wings. The fuselage is just there to hold the wings, as long as the wings a parallel the plane should fly properly.

2nd, with the main wing installed on the plane, you need to attach the horizontal stab (the part the moveable elevator connects to ) and insure it is parallel with the main wing.
You do this as follows:

Measure from each wingtip on the main wing to the tip of the horizontal stab. You want the same distance on each side.

Once you have the horizontal stab centered (equal distance on both sides ), from the rear of the planesight forward and make sure the horizontal stab is even with the main wing. Then you can glue/epoxy the horizontal stab in place.

What is just as important is the incidence. Incidence is the angle the main wing and horizontal stab are at. MANY planes are at 0/0 - the maing wing is at 0 degrees and the horizontal stab is at 0 degrees. Just because the plane may be an ARF or a kit you shouldnot assume the incidence is correct. If the incidence is wrong the plane can jump off the ground before it is ready to fly (too much positive incidence), can take forever to get off the ground (too much negative incidence ) and/or not fly/handle properly. If the instructions OR the the plans do not state an incidence, use 0/0. You will need an incidence meter for this. Robart and Great Planes make very good ones at a reasonable price. I prefer the GP unit over the Robart unit.

What Campy said is right on the money, but I'll add one thing.

After placing the wing on the plane, measure from each wingtip to the end of the fuse to make sure it is straight. (Then go on to Campy's step 2)

Also, before you try to do anything with incidence, see if the manual or plans mention what the incidence should be. If they don't tell you what to look for, there's no sense in trying to adjust it.

Your picture shows the fuselage on a tilt, as stated your landing gear is off. I would be more concerne with what appears to be washin on the right wing, looking from the rear. Make sure your wing is not twisted; It could be corrected while covering or steaming and twisting back into shape before covering.

i do everything the same way these fellas say but i use a string to measure from the center of front fuse to stab tip with a stikpin on the string at the front.like they say dont trust the landing gear to be level.before i glue the stab in place i check from my workbench to each tip of stab also, to make sure it is level.

As a hint afterwards, if you are using rubber bands to secure the wing to the fuselage, I use a very thin piece (line 1/16 inch wide) of black covering (contrasting) to form a line along the centerline of the top of the fuselage with the wing perfectly centered. I iron that on and put another layer of clear over that so it stays put, then cut it along the fuselage where the TE and LE meet. Then re-iron the covering strip so that it won't lift in flight. Use this line to align the wing to the fuselage then secure with your rubber bands. Then after you are done, and you have followed all the above instructions on the horizontal stab installation, you can be assured that all is properly aligned and good and straight. At least it will look good.. it will fly just fine no matter.

Appreciate the help. Will remove the landing gear and block the fuse to set the wing. I agree there seems to be a little washout on the right side and will need to figure out how to address this. Going to work on that this weekend.

Thanks - Hans