moses

Iā€™m assembling my new Katana GS40 ARF and everything looks good so far. The next step is to install the fairings. The instructions say to use a ruler and measure up from the bottom of the fuselage to the trailing edge of the wing ā€“ and then to move back use that same measurement at the rear of the fairing. The pictures show this procedure clearly.

I noticed that using this procedure, the fairings will not line up with the horizontal stabilizer. For example, if I were to extend a line from the trailing edge of the wing to the leading edge of the horizontal stabilizer, the rear edge of the fairings will be above this line. I assume I should just follow the instructions and that the fairings should not line up with the horizontal stabilizer. Could you folks confirm this please.

Thanks,
Moses

STLPilot

My Feedback: (21)

Just make sure the front of the fairing lines up with the trailing edge of the wing, top and bottom.

Then put a straight edge (18" metal ruler works best) on the top of the wing at the top of the tip of the trailing edge and tight against the fuse and lay it on the h-stab.

Then mark your line. Then remove the monokote on the fairing and fuse where they butt up. The fairing is easy to remove. Just lift each color then run your razor down the fairing. Then epoxy it on with 10 minute epoxy. Again while it's drying have some alcohol ready. Make sure you line the front of the fairing up with the trailing edge, no brainer. Then put your straight edge on the h-stab to the top of the trailing edge again, tight to the fuse. Then move the fairing tight to the straight edge.

The incidence for the fairing, h-stab and ailerons are 0.

moses

Thanks for the speedy reply. That is exactly what I needed to know. Only a small discrepancy between the two methods but I like your method better.

Moses

STLPilot

My Feedback: (21)

Sure no problem. An extra set of hands holding the straight edge really helps. Especially because you technically don't have anything to put the straight edge on when you line it up on the tip of the top of the trailing edge.

I'm no Picasso, but either was he until 50 years later. Wouldn't be too surprised if I saw this sketch in the museum of engineering in 100 years.

ACS

My Feedback: (13)

I finished my Katana before this post. It sounds like I was wrong in following the directions. My fairings are above the stab.
Have not flown it yet, is this going to be a big problem and change the flight characteristic. I hate to think that someone
could do something wrong when they follow the manufactures instructions. If so what can be done about now?

STLPilot

My Feedback: (21)

I just looked at the manual and it does not say anything about installing the fairings. Honestly when I built mine I never even opened the manual, just glanced it. We did not write the manual, we did some of the slight design changes for the airframe and only as recommendations to Accel, in which they did make the changes.

There are a couple of discrepancies in the manual because it was written for the older version Katana. Like the way the wires go into the fuse. You don't have to run the servo wire for the throttle so far back. You can insert it just behind the main spar under the wing. Also the tail feather wires, after they exit the 2nd hole don't run them down the wing, just cut a hole in the wing where they exit and pull them up to the hatch opening.

Also some of the rudder monokote has to be cut, just hold the rudder up to the light. You will also have to bevel the wood with a razor where you score the monokote.

The assembly is still really simple. How far up are the fairings from the incidence?

ACS

My Feedback: (13)

STLPilot, if you look at page 6 in the manual that I have it gives clear instructions on how to install the fairings,
just as moses had described in his post. I understand that OMP did not write the manual. The fairings are 5/16" up
from the stab. I am looking for some help in understanding how this will effect the flying and is it worth my time and
effort to try and correct.

STLPilot

My Feedback: (21)

OK. My manual has a blank page for page 6. Something must of happened at the printer.

Can someone take a picture of it please, maybe I'm wrong about 0 incidence, but that's what I heard. Does it say to have the fairings at 5/16th up?

Will 5/16th effect it? You won't know till you fly it. Might help it.

ACS

My Feedback: (13)

The manual does not say anything about the incidence or to have the fairings 5/16th up.
I have the CG set at 125mm. I flew the plane today and it seemed to fly on the nose heavy
side. I have scanned the page in the manual but I'm not sure how to post that file.

ACS

My Feedback: (13)

Looks like I might have got lucky or at least guessed right on the file.

WingShot

My Feedback: (3)

ACS is right, if you follow the directions as written in the manual, it does lead to the fairings a little higher than the stab. I didn't feel comfortable with that but that's what the manual said, and so I did it. Therefore, I'm in the same boat as ACS. I really like the quality of this ARF but the manual is one of the worst I've ever seen--and I've seen quite a few because I write manuals for a living as a Technical Writer.

STLPilot

My Feedback: (21)

Well I'm sorry about the manual, but I think it's wrong. But then again I could be wrong. This could be advice coming from the Accel Hobby designer. I will find out. I would not expect 5/16th up not to effect flight performance, if anything improve for 3D, but not for pattern.

I was under the impression that the incidence is 0 for the motor, fairings, ailerons and stab.

If your CG is 135-140 MM then it's not nose heavy. What's your CG?

Hopefully Mike will tune in today.

Spacey

Ahh Dion I agree with you on this one. Doesn't make much sense to have the fairings go up at the back. I would also think that they would be exactly in line with the wing centre line.

AFSalmon

My Feedback: (3)

The incidence should be zero on all surfaces. Don't know why Accel would suggest otherwise but that was never my input when tweaking this model for them and this is the first we saw the final manual. Dion describes the correct method for installing the fairings. Use a straight edge lined up on the top of the stab and against the TE of the wing. Everything should be lined up this way.

Dion, I would suggest posting a correction on our website. Maybe just a quick description as above along with a photo of the plane with a straight edge on top of the stab and the fairing.

For those that installed per Accel's instructions, I can only say go fly and see how it does! It may be fine but my gut thinking is that it's going to act differently upright and inverted. Basically if they are a little high at the rear they will act slightly like spoilerons although we are talking about a VERY small flying area relative to the rest of the wing. If they do anything at all I would say they predominantly would add some drag versus making any noticeable flight performances.

STLPilot

My Feedback: (21)

Here is the updated instructions.

ACS

My Feedback: (13)

Mike and Dion thanks for helping clear this up. I just wish I did'nt have to take apart a new plane, some replacement parts would be nice.

sgillmore

My Feedback: (50)

I purchased one of these for my son. We just put the fairing on a couple days ago and I just found out today there's a problem. We took great care to assemble it properly according to the instructions. Now I find out today that it's put together wrong. IMO, replacement fairing should be provided at no charge. It's bad enough that we have to tear our new plane apart as a result of a screw up by the manufacturer. How Accel handles this issue will definitely decide whether I by another Accel kit.

Ok--now I'm really upset. I just noticed the date on the this thread. This has been a problem for almost a year and the manual in my box is still wrong!!! Am I just suposed to assume the manual that comes in the box is wrong and check the manufactures website before building a new plane.

STLPilot

My Feedback: (21)

We had the newly revised manual posted on our website and it was dated. You should just call Accel and see if they will replace some fairings for you.

sgillmore

My Feedback: (50)

Called Accel and they were very helpful and agreed to send me replacement fairings at no charge. I sure wish Accel would have taken a few extra steps to get addendums or notifications to the retailers, so I could have avoided this headache.

I guess the lesson learned here is check for updated manuals before every build!