Very nice 

Is this made by you? Could you share the specifications?

Electronics:
2205@2300KV
30A ESC
5x4.5 Prop
850mAh Lipo
2x 5g servo
For more detail please see the video description.

Yes, this is made by me, and all specifications are in the video description. With some useful links. 

Beautiful plane. Is there any plan available?

 
This is a FliteTest model
Model name: FT DR1 Triplane
Free PDF plan also available.

Hi MakerHand, the plane is indeed beautiful. But you seem to have trouble landing safely. I think while landing you should give more elevation, and intermittent increment of throttle. That should help little nose up for a perfect landing and would prevent early breaks which causes the plane tumble forward.



This is a scaled version of FT simple cub , to suite limited space available in my backyard.

 
You are 100% right but the problem is my wheels are small and I'm landing on grass, not a smooth surface that's why it always flip over, because landing gear stuck in grass.

If so , try a float , which would slide easily over grass.