N188LR First Flight

[rocketman2tm]

I introduced N188LR to the sky Easter morning. Wow that thing can climb! The flight was uneventful and I have since taken it up this morning as well.

Two things that have come out of the flights so far:

I'm going to add another degree of pitch to the prop before the first flight. I'm into the yellow arc rpm at 100 mph at 86 rpm. Considering that I can apparently reach 500 feet AGL in 2600 feet, I probably can afford to give up some climb.

Left wing seems heavy. I have to apply a slight amount of pressure to the stick to counter it. What adjustment needs to be made to correct this? I want to say that I'll be making an adjustment to the light strut rod ends, but do I adjust the front or the back and do I adjust the heavy wing or the light wing?

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Made a short video of the first takeoff and landing. I'm no Trent Palmer yet.
https://www.youtube.com/watch?v=89C9lM3vmx0

Specs:
Super sport 7, Rotax 912is Sport, Whirlwind 72", Oratex, 10 inch Dynon Skyview, Random $70 android tablet from Amazon, Aeroled lights, Ack elt, 8.5 x 6.00 Dessert Aero Classic tires, Aluminum Grove gear, faired wing struts (not the new streamlined ones), Rust-oleum cherry red (matches the red Oratex pretty well and easy to touch up)

821 lbs empty weight.

[Eric Page]

She's a beauty! Well done, and congratulations!

[alexM]

Awesome. Thanks for the ride. Plane looks great

[Dave S]

John,


"Left wing seems heavy." Pretty much means you did your building accurately....:)

If you ever read the classic, "Stick & Rudder", the author goes into a short discussion about when standard aircraft came off the production line way back whenever, the first flight was followed by an adjustment of washout to correct the "heavy wing". If the wings are built entirely symmetrical with respect to washout; P factor will assure that the left wing will want to descent if you have an engine rotating to the right.

If you think about the aerodynamics, you will figure it out. Looking for a little more angle of attack in the heavy wing and/or a little less on the other side. Ideally a person will adjust one lift strut to increase washout a bit while adjusting the opposite side to decrease the washout a bit if necessary. Doing a half turn on one rod end at a time between test flights works well.

I favor leaving the rear rod ends alone as much as possible (so the dihedral stays the same on the greater load bearing struts) and adjusting the front but it has been done both ways and in combination.


Really nice job on the plane!:)

I do like that "from the garage...." logo!

[bumsteer]

Nicely done. Congrats!!

Rick

[jiott]

Agree with Dave on washout adjustment. I would recommend alternating the adjustment from side to side so each side ends up with roughly the same amount of change, + on one side, - on the other. If you did all the adjustment on one side there is the possibility that you might remove most of the washout on that side, which is not a good thing. When I did mine, John McB said not to do more than two turns on any one rod end. That would be pretty drastic. I believe I ended up with one turn on some rod ends and a half turn on the others, tweaked in over several test flights. Also I would recommend you correct any yaw trim with a fixed rudder trim tab before you finalize your wing strut adjustment, because a yaw error will affect the heavy wing error to some extent. Nothing to get real concerned about, just work both of them together.
Yes, congrats on a beautiful bird.

[Denalifox]

Ha, I see Im not the only one who stumbled upon Cherry Red Rustoleum. haha. congrats!

[rocketman2tm]

The cherry Rust-oleum is a really close match and I would much rather scuff and touch up with a rattle can. This is a bush plane after all.

[Maverick]

Agree with Dave on washout adjustment. I would recommend alternating the adjustment from side to side so each side ends up with roughly the same amount of change, + on one side, - on the other. If you did all the adjustment on one side there is the possibility that you might remove most of the washout on that side, which is not a good thing. When I did mine, John McB said not to do more than two turns on any one rod end. That would be pretty drastic. I believe I ended up with one turn on some rod ends and a half turn on the others, tweaked in over several test flights. Also I would recommend you correct any yaw trim with a fixed rudder trim tab before you finalize your wing strut adjustment, because a yaw error will affect the heavy wing error to some extent. Nothing to get real concerned about, just work both of them together.
Yes, congrats on a beautiful bird.

I followed Dave's procedure as related to me by Eddie. Something I did was to take pictures of the rod-ends before and after making adjustments just for my own references as I made the different adjustments. That way I could count threads as needed to keep track of the adjustments to each side for the logbook. I am going to add the rudder trim tab this weekend. Once is in place, I may or may not need to make one more adjustment as Dave mentions because of the rudder effect to the heavier wing.

[efwd]

Nice airplane. Congratulations!
When my heavy wing was discovered on its first flight I spoke with John M as well. The first thing he asked was "Were you in trim?" He suggested I fix or make sure the turn and slip was correct. I made sure that was the case and then adjusted my rod ends per Paul's suggestion. He had told me, while getting my refresher (before 1st flight) at Stick and Rudder, that I could expect a heavy wing and when I adjust the rod ends, start by screwing the bearing in as to not get too many threads showing. That meant adjusting the "light" wings front bearing first. I turned 1.5 turns in on the front bearing of the light wing and that is all I needed after I had added the trim tab to the rudder.

[jrevens]

Congratulations John! Good job! The other guys have pretty much covered this, but here is a excerpt from an explanation of wing rigging that I saved. I believe it may have come from John McBean or someone else at the factory... sorry that I don't know for sure. It was helpful to me. I had the heavy left wing also. Keep in mind that besides P-factor, you also probably have just a pilot and no one in the passenger seat. This is a factor in our light aircraft.



Wing Rigging Adjustments



…you can adjust either side… we will typically decrease the angle of incidence first, then increase on the opposite wing if needed. Try to make changes equal.

For example… We have a slight left turn… or heavy left wing as they say.

We have determined that we do not have a yaw issue that is causing the left turn.


We adjust the right wing rear lift strut rod end out 1 turn… record our change and pre-flight for a test flight. Decreased Twist (wash-out).

Not enough… so now we’ll adjust the left wing rear lift strut rod end in 1 turn… record our change and pre-flight for a test flight. Increased Twist (wash-out).

Still not enough… adjust the right wing front lift strut rod end in 1 turn… record our change and pre-flight for a test flight. Decreased Twist (wash-out).

Still not enough… adjust the left wing front lift strut rod end out 1 turn… record our change and pre-flight for a test flight. Increased Twist (wash-out).

You may need to make a ½ turn or maybe a 1 ½ turn. All depends on the severity of the roll rate.


Always check to make sure that adequate rod end thread engagement is maintained.

[DesertFox4]

Great looking Kitfox John. Big congrats!

[desertdave]

Looks great! Congrats!!

[rocketman2tm]

Thanks for all of the responses guys. I'm having fun with this thing!

I got to fly this morning for the first time since this post. I made a one turn adjustment to the right rear lift strut attach point. The plane does not want to roll to the left quite as much as it did before. I think before the next flight I'll make an adjustment to the left rear lift strut attach point by one turn. As far as the rudder is concerned, I can keep the ball in the center with wings level with the stick and my feet on the floor, so I believe this can be resolved with lift strut adjustments. Hoping to get this resolved so I can start doing some stall testing.

I added another degree of pitch to the prop as well and saw about 110 (10 mph improvement). Considering I live in Wisconsin, I don't mind giving up a little climb for cruise.

I did my first pavement landings with the plane today as well. Very good manners on pavement, I was quite happy about that. When I measured the toe on the landing gear, I was around 0.25 degrees toe in on the right side and 0.40 degrees toe out on the left. I was debating on getting a 0.5 degree shim for the left to bring it in, but I don't know if it is necessary.