Рет қаралды 6,182
I ordered this ready-to-fly (RTF) J3 Cub model from Banggood on the first week of September right before Labor Day. It was on sale at $89.99, plus $2.70 for shipping and $1.80 for shipping insurance, so I paid a total of $94.49. However, the price may have changed, but I suspect it will go back on sale again if you are willing to wait:
www.banggood.com/XK-A160-J3-S...
It was not in stock when I placed the order, but I did not care since I was not in a hurry to receive it. It was delivered to my home late October.
I think what I paid was a very good price for such a complete package of a nicely-sized parkflyer with a respectable 650mm wingspan. It is not too small and it is not big either.
In the first and three episodes, I showed the unboxing, the assembly, and the maiden flight:
• XK A160-J3 Skylark 4CH...
• XK A160-J3 Skylark 4CH...
• XK A160-J3 Skylark 4CH...
My initial observations were all good. However, as I watched more reviews of this airplane on KZbin, I realized that many people have had or have been having an issue they called a "tip stall". The plane was becoming unstable during some turns and then stalling or going into a spin without warning. A video posted by KZbinr Albert Kim was especially curious, because his plane crashed during a turn, although it had plenty of airspeed:
• Multiprotocol Module T...
Watch that video at 9:52 and at 10:12. After watching that video, I became concerned and wanted to investigate this issue further to figure out what is the culprit of these crashes and if they are systemic to this airplane, or even to the whole XK line.
In the fourth video, I presented my findings and what I believed the cause of this issue was. And my findings were really bad news in my opinion. I think this product should have never been released for sale. This instability issue seemed to be widespread enough that I believe it is a design or programming flaw of the stabilization system.
• XK A160-J3 Skylark 4CH...
In this video, I am doing another flight of this airplane, but this time using my beloved RadioMaster TX16S transmitter. Despite my good initial impression during the maiden flight, I did not have the same performance and stability in this flight. I am suspecting an issue with the calibration of the stabilization system. The plane also felt tail heavy in the "expert" mode, which I did not like at all. This flight was not that much fun for me, although I had more precise control via my TX16S. If you own any XK airplanes, I suggest you check them before your next flight using the procedure I detail in the previous episode. GOOD LUCK!
My next goal is to disable the stabilization system completely and flying this airplane manually without any stabilization. If needed, I am also going to adjust the center of gravity (CG) adding some weight to the nose. If I succeed, I will post another update video.
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Stay safe and healthy! Cheers!