I wasn't sure which group to post this in, but here is my situation:

I obtained a Seagull Harrier 46 with the horizontal stabilizer glued in, not quite parallel to the wings. I would estimate that it is off by 1 to 1.5 degrees. Can this be trimmed out in flight or should the stabilizer be removed and refitted?

Thanks,
G

It could be trimmed out in flight, but the plane wouldn't fly as nice. I had two planes built for me by other builders, and both rear stabs were off by 2-3 degrees. Both planes turned out to be poor flyers and were all over the sky on their maiden flight. One ended up crashing as a result. I would try to correct the horizontal stabilizer. A plane that's built straight and true will always fly better than one with a crooked rear stab.

It will fly fine. I always make it a point to get them parallel, but have flown dozens of planes over the years, with the stab off a little. Does not effect the flight, unless you are into precision aerobatics.

I'll see if I can remove the stab. Do you have any suggestions? The best I can think of is to try to get a razor blade in there and try to cut at the glue joint without tearing it to pieces. The wing is a two piece connected via two tubes, I wonder if it would be easier to try to straighten the wings because the horizontal stab looks perpendicular to the vertical "stab" (not really much of a stab as an extension of the fuselage). Any help would be appreciated.

Thanks,
G

This would be an easier solution but the other post scares me a little. All of the planes I have put together have the stab parallel to the wing and I've never flown one where this was not the case. I wish I could program this into to my RF G2 sim to see what it would be like.

I broke the horizontal stab from the fuselage in a minor crash a few months ago. BTW, this was on my Midwest Aerobat. When I put everything back together, I didn't notice that the stab was down on one side as compared to the wing until after I flew it a few times. The only real noticeable difference was that I needed a little left aileron trim and that was about it. It flew just fine otherwise. I left it alone.

DS.

Before you start tearing anything apart, take the time to determine which surface is really wrong. Get out a square and check the alignment of the horizontal stab and the fin. If they are square then you may want to adjust the wing.

I faced the same alignment problem with the plane I just finished. The fin was built into the plane before covering. Since this is a small pattern plane I was VERY careful when installing the horizontal stab. I am certain it is exactly square to the fin. When I finally got to the step where I attached the wing I found it was not parallel to the horizontal stab. It also appeared by eye that the wing was not quite square to the fin. I ended up enlarging one of the forward wing holes and shimming a bit to lower one side of the wing to bring it in line with the other surfaces. I still have to check the incidence to confirm that's correct.

Since the angle is so small, I guess I'll give it a try and if I can't hover it (it is supposed to be extremely easy to hover this and I can hover my Modeltech Twister), I'll fix the problem.

Thanks for all the input. Any other comments would be appreciated.

G

I am certain that the horizontal and vertical stabs are perpendicular. I can very nearly correct the problem shimming the wing halves, but it leaves a gap between the wing and fuse. Since they are removeable, I didn't want to fill the gaps with anything permanent. I'm not sure what the best answer is. Should I worry about the 1/8" gaps that I introduce? Is that better than flying with them misaligned?

Foam tape or silicone can fill gaps.

I have determined that the tubes that are mounted inside the fuse (the wing tubes pass through these) are not square to the fuse, which is causing them to tilt about 1 degree. It seems to me that the correct answer is to correct that problem, but it does not look easy for me to accomplish. That leaves me, I think, with two other options: 1) shim the wings or 2) fly as is and trim out. I'm so confused, this type of problem is new to me. Please continue helping as I have not decided what to do as of yet.

Thanks,
G

Keep in mind that mine were at least 2-3 degrees off. I want to say even 4 degrees. One plane required almost full aileron trim ( close to 5/16" ) to fly level. Whenever I pulled a loop, the plane would veer off sharply to one side and went over the pitt area. None of my other planes does that. Ideally, you want as little trim as possible. It might not be that bad in your case since your rear stab is only a little off.

I figure a picture is worth 1000 words. I added a few pics to my gallery, please check them out and see what you think. If you would like another angle, let me know.

Thanks,
G

Personally, if I can see a misalignment during build/assembly, I fix it. Doesn't matter if it's a Cub or an aerobatic plane. When I pull back on the stick I want a loop, not a corkscrew like Richard described. Choose the method which seems best, and deal with it. From everything you've said, it sounds like you've identified the wing tube as the primary cause. Maybe some pics of that area would help people suggest a fix that's not as bad as you think it will be. Note, you can post pics in a thread too. Use the add reply button, instead of the quick reply box that's at the bottom of the thread. Then hit the "Click here to upload!" link in the bottom left corner of the text box.

GMoneyPit, From what I can see in your pictures I think it's acceptable. I have seen way worse, and have flown way worse with minimal troubles. You mite have to do a little extra trim work but also IMO that type of plane is not a full on pattern ship or a slick Warbird. For sport and 3D I say.............. Fly it like ya stole it and have fun.

Joe A.

This problem was discussed in great detail in the RC Pattern column in the last issue of Flying Models.

my eye says it is the stab and NOT the wing. The wing looks square to the fuse in the pics Not sure what kind of flying you're going to do but it should be ok