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?

PXL_20210407_121945346.jpgPXL_20210407_121957140.jpgPXL_20210407_122057321.jpgPXL_20210407_122114674.jpg

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.