It was a bit more windy today than yesterday, so a perfect "laboratory" to really assess the wind handling of the Mig29 V4M3e3... :)
I am happy to report that it handles the wind amazingly well. Although I think we can never fully eliminate Elevon Polar Pitch Effect (EPPE), it is reduced considerably with the mods Stephan and I have made. If it is there, it is very subtle and believe me I flew so many figure 8s throughout 13 flights this morning looking for EPPE, I almost got dizzy... :/
So you might ask yourself why we seem to be so anal about this whole EPPE thing, why don't we just fly our planes to accommodate for it? Well true, that can be done, but I think that since both Stephan and I are trying to push ourselves to fly more scale and execute more precision aerobatics and maneuvers, we would rather be proactive and make the tail slide out in a "drift turn" when we choose to rather than be reactive and try to compensate for it.
As well, if you think about it, the number one maneuver you do with your plane during a flight is turning. Due to confined flying areas, radio range, plane orientation, we are constantly turning our planes. So if there is any maneuver where I and I think Stephan is the same want our planes to be smooth, crisp and predictable it is in a turn as quite often we are coming out of a turn to do another aerobatic maneuver or we are turning shortly after a maneuver...in my case often to miss a tree or some other such obstacle! Since the wind is an unpredictable variable, the more steady and predictable the plane is in windy conditions and the less I have to compensate for certain behaviors the better, at least for me.
In the diagram below I have tried to show what I mean by the tail being pushed out in turns. I first noticed it months ago when I was flying my FRC Foamies F15 MK2 which has fairly scale, small elevons and my stock Mig29 V3 with full size elevons. It was around this time that Stephan and I started sharing ideas for modifying our planes to fly the way we want them to. Both planes were the same weight and had the same power system, but the tail end of the Mig would continually get pushed wide, making turns wider and needing either more speed or more room to make a 180 degree turn with normal, smooth inputs.
Another bonus I found in the wind today with the added stability mods we added and reshaped elevons and vertical stabs/rudders was a much quieter and cleaner plane, especially in the back end. The stock Mig29 V4 although probably one of if not the most stable stock park jet I have ever flown, it still twitches and bobs around a bit in the wind. Not like it is having a seizure or anything, but it isn't what I would call "quiet". It also suffers occasionally from "tail wag" in the yaw axis when entering a turn in the wind. I know that due to the "toed in" vert stabs where the back of the vert stabs is angled out to create a wedge, the plane is self correcting and believe me this is a great feature, but it feels sometimes with the stock plane there is a lot of turbulence going on back there in a turn in windy conditions.
In this picture below I have tried to explain what I mean as we are often referring to tail wag, fish tailing when talking about EPPE as well. What I am trying to describe is more pronounced in the yaw axis where it looks like a fish swimming into the turn as I roll the plane on it's side. As you look at this picture, imagine you are looking at "God's eye view" from above the plane.
Although this phenomenon is not completely eliminated with the V4M3e3 mods, it is greatly reduced. The toed in/out vert stabs that create the wedge of stability are still doing their corrections, but there seems to be much less turbulence going on in the back end of the plane. Perhaps this is in part to the slightly smaller elevons not creating as much drag and turbulence while the plane is turning, but perhaps it is also due to the vertical trailing edge on the V4M3e3 as shown in comparison to the stock V4 below. I'm not sure and without a wind tunnel to verify, I just have to go with my best guess and "seat of the pants" feel as I fly it. I believe that the vertical trailing edge creates less turbulence than the angled trailing edge, but just my theory. What I do know it is that it is an improvement in stability, precision and handling for sure... :)
So as always, perhaps there is a bit more tweaking to do with the elevons and vertical stabs, but I for one am extremely pleased with the improvements these mods have provided me. As Stephan and I discussed on yesterday's post of my video, perhaps there could still be some reduction in the tail plate and again, these assessments in this and previous posts are only my judgments based on how I like to fly. The movement of the Center of Lift (COL) and Center of Gravity (CofG) that occurred as a result of these mods is still very manageable. However, when I think of the slight reduction of the elevons and the tail plate combined with the slight addition to the trailing edge of the KF we made equating to the CofG moving 3/4" on a 40" long plane, perhaps we are getting close to the edge of how far we can go? Interesting thoughts, but in my humble opinion, this plane certainly rocks and performs beyond what I could have expected once again... :)
Cheers,
Scott
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